Abrasive particles containing coatings, abrasive articles containing abrasive particles, and methods of forming

Abstract

The following is directed to an abrasive particle having a body including a core and a coating covering at least a portion of the core. The coating can include a lithium content. In some embodiments, the coating can further include silicon, oxygen, or a combination thereof.

Description

[Technical Field]

[0001] The following is directed to abrasive particles comprising a coating over a portion of a core, abrasive articles comprising the abrasive particles, and methods of formation. [Background technology]

[0002] Abrasive articles are used in material removal operations such as cutting, grinding, or shaping a variety of materials. Fixed abrasive articles contain abrasive particles held in a bond material. The bond material can include organic and / or inorganic materials. Organic bonded abrasive articles often perform poorly under wet grinding conditions, particularly in wet grinding operations. The industry is continually striving for improvements in abrasive articles. [Brief explanation of the drawings]

[0003] The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. [Figure 1] A flow chart illustrating a process for forming abrasive particles is included, each of which can include a coating over a core according to an embodiment. [Figure 2A] 1 includes an illustrative view of a cross section of an abrasive particle according to an embodiment. [Figure 2B] 1 includes an illustrative view of a cross section of an abrasive particle according to an embodiment. [Figure 3] Included are atomic force microscope images of abrasive particles. [Figure 4] 1 includes an illustrative view of a cross section of a body of a bonded abrasive article according to an embodiment. [Figure 5] 1 includes an illustrative diagram of a process for forming an abrasive article according to an embodiment. [Figure 6] 1 includes an illustrative view of a cross section of a coated abrasive article according to an embodiment. [Figure 7] Includes a photograph of Comparative Example 7. [Figure 8A] 1 includes an SEM image of the core of an abrasive particle according to an embodiment of the present disclosure. [Figure 8B]1 includes an SEM image of the core of an abrasive particle according to an embodiment of the present disclosure. [Figure 9] Included is a plot of G-ratio versus MRR for the abrasive wheel samples. [Figure 10A] Includes SEM images of abrasive particle samples. [Figure 10B] Includes SEM images of abrasive particle samples. [Figure 10C] Includes SEM images of abrasive particle samples. [Figure 10D] Includes SEM images of abrasive particle samples. [Figure 10E] Includes SEM images of abrasive particle samples. [Figure 10F] Includes SEM images of abrasive particle samples. [Figure 10G] Includes SEM images of abrasive particle samples. [Figure 10H] Includes SEM images of abrasive particle samples. [Figure 11A] SEM images of additional samples of abrasive particles are included. [Figure 11B] SEM images of additional samples of abrasive particles are included. [Figure 11C] SEM images of additional samples of abrasive particles are included. [Figure 11D] SEM images of additional samples of abrasive particles are included.

[0004] Those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0005] The following description in combination with the drawings is provided to aid in understanding the teachings provided herein. The following disclosure focuses on specific implementations and embodiments of the teachings. This focus is provided to help explain the teachings and should not be construed as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application.

[0006] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that includes a list of features is not necessarily limited to only those features, but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive "or" and not an exclusive "or." For example, condition A or B can be satisfied by any one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0007] Additionally, the use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This specification should be read as including one, or at least one, and the singular as including the plural, and vice versa, unless it is clear that this is meant to be otherwise. For example, where a single item is described herein, two or more items can be used in place of the single item. Similarly, where two or more items are described herein, the two or more items may be replaced with a single item.

[0008] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and are not intended to be limiting. Unless specific details regarding particular materials and processing acts are described, such details may include conventional techniques that can be found in reference books and other sources within the manufacturing arts.

[0009] Embodiments are directed to abrasive particles, each of which may include a coating covering a core. The abrasive particles may include a batch of abrasive particles or may otherwise have a suitable statically related sample size. The abrasive particles may be suitable for forming a variety of abrasive articles, including, for example, bonded abrasives, coated abrasives, and fixed abrasive articles such as superabrasive articles. The abrasive particles may have improved bonding to the binding material contained in the abrasive article, facilitating improved performance of the abrasive article.

[0010] Embodiments further relate to processes for forming abrasive particles. The processes can include a drying process to facilitate the formation of coatings with improved properties. For example, the processes can enable the formation of abrasive particles with improved average coating thickness, improved coating thickness standard deviation, and improved abrasive particle morphology. In another example, the coating can facilitate improved moisture resistance of the abrasive particles and the formation of an interface between the abrasive particles and the binding material in the abrasive article with improved moisture resistance.

[0011] Further embodiments are directed to abrasive articles comprising a bond material and abrasive particles. The abrasive article can have improved bonding between the bond material and the abrasive particles, which in turn can help improve the performance and / or properties of the abrasive article. For example, the abrasive articles of embodiments herein can have improved grinding performance under wet conditions, improved performance after aging, and extended service life.

[0012] Abrasive articles can include, for example, coated abrasives such as belts and discs, bonded abrasives comprising organic and / or inorganic bond materials, and fixed abrasives including superabrasive tools. Exemplary bonded abrasive articles can include, for example, grinding wheels, cut-off wheels, ultra-thin wheels, combination wheels, cut-off wheels, chop saws, or any combination thereof.

[0013] 1 includes a flowchart illustrating an exemplary process for forming abrasive particles, each of which may include a coating overlying a core. At block 101, the process may include forming the coating. Forming the coating may include forming a mixture including a first material, a second material, and optionally a third material. A suitable mixing operation may be utilized to achieve a homogeneous dispersion of the components within the mixture.

[0014] Forming the coating can include forming a mixture including a first material that includes silica. For example, the first material can include a dispersion of silica in a solvent. The solvent can be aqueous or organic. In some aspects, the first material can include silica nanoparticles. In one embodiment, the first material can be a dispersion of silica nanoparticles in water.

[0015] In another embodiment, the coating can include a specific content of a first material comprising silicon (i.e., silica) relative to the total weight of the mixture or relative to the total weight of the first portion of the coating (e.g., 202), which can facilitate improved formation and properties of the coating. For example, the mixture and resulting coating can include at least 10 wt. % of the first material comprising silicon relative to the total weight of the mixture, e.g., at least 15 wt. %, at least 20 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %, at least 60 wt. %, at least 70 wt. %, or at least 80 wt. % of the first material comprising silicon relative to the total weight of the mixture. In another example, the mixture can include 95 wt. % or less of the first material comprising silicon relative to the total weight of the mixture, e.g., 90 wt. % or less or 85 wt. % or less of the first material comprising silicon relative to the total weight of the mixture. It will be understood that the mixture can include the first material comprising silicon in a content including any of the minimum and maximum percentages described herein. Unless otherwise specified, the content of any species (e.g., silicon, lithium, potassium, sodium, aluminum, etc.) is calculated by ICP analysis, as described in the measurement of abrasive particles (Sample S1) in Example 1 provided herein. As used herein, ICP can be performed using an ICP-OES Agilent 5110 or equivalent. The abrasive grain sample can be prepared as follows: 0.5000±0.0100 grams of the abrasive grain sample and 3.0000±0.0100 g of lithium tetraborate are weighed and added to a Pt / Au crucible; 200 μl of lithium bromide solution is added to the crucible and mixed thoroughly; the mixture is melted at 1300±30° C. and then cooled to form a molten sample; the molten sample is transferred to a beaker; approximately 125 mL of DI H2O and 25 mL of HCl are added to the beaker and heated and then cooled to obtain a solution; and the solution is subjected to ICP testing.

[0016] Forming the coating can include forming a mixture including a second material comprising lithium. For example, the second material can include lithium silicate. In certain embodiments, the coating can include a specific content of the second material comprising lithium relative to the total weight of the mixture, which can facilitate improved formation and properties of the coating. For example, the mixture can include at least 10 wt. % of the second material comprising lithium relative to the total weight of the mixture, e.g., at least 15 wt. %, at least 20 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %, at least 60 wt. %, at least 70 wt. %, or at least 80 wt. % of the second material comprising lithium relative to the total weight of the mixture. In another example, the mixture can include 95 wt. % or less of the second material comprising lithium relative to the total weight of the mixture, e.g., 90 wt. % or less or 85 wt. % or less of the second material comprising lithium relative to the total weight of the mixture. It will be understood that the mixture can include the second material comprising lithium in a content including any of the minimum and maximum percentages described herein.

[0017] In one non-limiting embodiment, forming a coating, e.g., a first portion of a coating, can include forming a mixture including an optional third material comprising potassium. For example, the third material can include potassium silicate. In certain embodiments, the coating can include a specific content of the third material relative to the total weight of the mixture, which can facilitate improved formation and properties of the coating. For example, the mixture can include at least 0.01 wt% of the potassium-containing third material relative to the total weight of the mixture, e.g., at least 2 wt%, at least 4 wt%, at least 6 wt%, at least 8 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, or at least 50 wt% of the potassium-containing third material relative to the total weight of the mixture. In another example, the mixture can include no more than 70 wt% of the potassium-containing third material relative to the total weight of the mixture, e.g., no more than 65 wt%, no more than 60 wt%, or no more than 55 wt% of the potassium-containing third material relative to the total weight of the mixture. Additionally, the mixture may include a third material including potassium, in a content including any of the minimum and maximum percentages described herein.

[0018] In yet other embodiments, forming the coating can include forming a mixture including an optional fourth material comprising sodium. For example, the fourth material can include sodium silicate. In certain embodiments, the coating can include a specific content of the fourth material relative to the total weight of the mixture, which can facilitate improved formation and properties of the coating. For example, the mixture can include at least 0.01 wt% of the sodium-containing fourth material relative to the total weight of the mixture, e.g., at least 2 wt%, at least 4 wt%, at least 6 wt%, at least 8 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, or at least 50 wt% of the sodium-containing fourth material relative to the total weight of the mixture. In another example, the mixture can include 70 wt% or less of the sodium-containing fourth material relative to the total weight of the mixture, e.g., 65 wt% or less, 60 wt% or less, or 55 wt% or less of the sodium-containing fourth material relative to the total weight of the mixture. Additionally, the mixture may include a fourth material including sodium, in a content including any of the minimum and maximum percentages described herein.

[0019] Referring now to block 102 or FIG. 1 , the process can further include applying a coating to at least a portion of the core. Applying the coating to at least a portion of the core can include mixing the core with the mixture formed in block 101. A mixing device can be used to facilitate the formation of a uniform mixture of the core and the mixture. Examples of mixing devices can include a Hobart mixer, a Hudson mixer, or the like, or another mixing device.

[0020] In the next step, block 103 of FIG. 1 , the process can further include drying the core coated with the mixture. Drying can include drying at a temperature sufficient to form a coating over at least a portion of the core. In particular, drying can be performed at a temperature of at least 15°C, or at least 20°C, or at least 30°C, or at least 40°C, or at least 50°C, e.g., at least 60°C, or at least 70°C, or at least 80°C, or at least 90°C, or at least 100°C, e.g., at least 120°C or at least 150°C. In yet another example, the drying temperature can be 400°C or less, e.g., 350°C or less, 300°C or less, 250°C or less, 200°C or less, e.g., 190°C or less, 180°C or less, 170°C or less, or 160°C or less. Furthermore, the drying temperature can be within a range that includes any of the minimum and maximum temperatures described herein. In particular examples, the drying temperature may be in the range of 100°C to 180°C or in the range of 140°C to 150°C.

[0021] In some embodiments, drying can be carried out in an oven. In other embodiments, drying can be carried out for a specific period of time sufficient to form a dry coating on the core. For example, drying can include drying the coated core for at least 2 hours, e.g., at least 4 hours, at least 6 hours, at least 8 hours, at least 10 hours, at least 12 hours, or at least 14 hours. In another example, drying the coated core can be carried out for 20 hours or less, e.g., 18 hours or less or 16 hours or less. Furthermore, drying can include drying the coated core for a period of time ranging from any of the minimum and maximum values ​​described herein. In a particular example, drying can include drying the coated core for 12 to 16 hours.

[0022] It is noteworthy that forming processes disclosed in embodiments herein can enable improved formation of abrasive particles. For example, the abrasive particles when dry can contain 30% or less by weight of agglomerated abrasive particles, based on the total weight of the dry abrasive particles, for example, 25% or less by weight, 20% or less by weight, 15% or less by weight, 10% or less by weight, 5% or less by weight, 2% or less by weight, 1% or less by weight, 0.8% or less by weight, 0.5% or less by weight, 0.3% or less by weight, or 0.1% or less by weight of agglomerated abrasive particles, based on the total weight of the dry abrasive particles. In certain examples, the dry abrasive particles can essentially consist of loose abrasive particles.

[0023] In some embodiments, the core can comprise an abrasive material including a crystalline material, such as a polycrystalline material, a single-crystal material, or a combination thereof, an amorphous material, a ceramic material, a glass-ceramic material, a superabrasive, a mineral, a carbon-based material, or any combination thereof. In a further aspect, the sintered ceramic material can comprise an oxide, a carbide, a nitride, a boride, an oxycarbide, an oxynitride, a silicate, or any combination thereof. For example, the core can comprise a material selected from the group consisting of silicon dioxide, silicon carbide, alumina, zirconia, flint, garnet, emery, a rare earth oxide, a rare earth-containing material, cerium oxide, a sol-gel-derived particle, gypsum, iron oxide, a glass-containing particle, and combinations thereof. In another example, the abrasive particles may also include silicon carbide (e.g., Green 39C and Black 37C), brown fused alumina (57A), seed gel abrasive, sintered alumina with additives, compacted and sintered aluminum oxide, pink alumina, ruby ​​alumina (e.g., 25A and 86A), electrofused single crystal alumina 32A, MA88, alumina zirconia abrasive (e.g., NZ, NV, ZF brands from Saint-Gobain Corporation), extruded bauxite, sintered bauxite, cubic boron nitride, diamond, aluminum oxynitride, sintered alumina (e.g., CCCSK from Treibacher), extruded alumina (e.g., SR1, TG, and TGII available from Saint-Gobain Corporation), or any combination thereof. In another example, the core may have a Mohs hardness of at least 7, e.g., at least 8, or even at least 9.

[0024] In another embodiment, the core can comprise non-agglomerated particles, non-shaped abrasive particles, shaped abrasive particles, or any combination thereof. For example, the core can comprise shaped abrasive particles, such as those disclosed in U.S. Patent Publication Nos. 20150291865, 20150291866, and 20150291867. The shaped abrasive particles are formed so that, for shaped abrasive particles having the same two-dimensional and three-dimensional shape, each particle has substantially the same arrangement of surfaces and edges relative to each other. Thus, the shaped abrasive particles can have high shape fidelity and consistency in the arrangement of surfaces and edges relative to other shaped abrasive particles in a group having the same two-dimensional and three-dimensional shape. In contrast, non-shaped abrasive particles can be formed through different processes and have different shape attributes. For example, non-shaped abrasive particles are typically formed by a milling process, which forms a mass of material, which is then crushed and sieved to obtain abrasive particles of a certain size. However, unshaped abrasive particles have surfaces and edges that are generally randomly arranged and generally lack any discernible two- or three-dimensional shape in the arrangement of surfaces and edges around the body. Furthermore, unshaped abrasive particles of the same group or batch generally lack a consistent shape relative to each other, resulting in surfaces and edges that are randomly arranged when compared to each other. Thus, unshaped or broken abrasive grain has significantly lower shape fidelity than shaped abrasive particles.

[0025] In certain embodiments, the core can include a sintered ceramic material having a particular average crystallite size. In some aspects, the average crystallite size can be less than 1 micron, such as 0.9 microns or less, 0.8 microns or less, 0.7 microns or less, 0.6 microns or less, 0.5 microns or less, 0.4 microns or less, 0.3 microns or less, 0.2 microns or less, 0.1 microns or less, 0.09 microns or less, 0.08 microns or less, 0.07 microns or less, 0.06 microns or less, 0.05 microns or less, 0.04 microns or less, 0.03 microns or less, 0.02 microns or less, or 0.01 microns or less. In another embodiment, the core 201 can comprise a sintered ceramic material having an average crystallite size of at least 0.01 micron, e.g., at least 0.02 micron, at least 0.03 micron, at least 0.04 micron, at least 0.05 micron, at least 0.06 micron, at least 0.07 micron, at least 0.08 micron, at least 0.09 micron, at least 0.1 micron, at least 0.11 micron, at least 0.12 micron, at least 0.13 micron, at least 0.14 micron, at least 0.15 micron, at least 0.16 micron, at least 0.17 micron, at least 0.18 micron, at least 0.19 micron, at least 0.2 micron, at least 0.3 micron, or at least 0.4 micron, or at least 0.5 micron. Further, the core can comprise a sintered ceramic material comprising an average crystallite size ranging from and including any of the minimum and maximum values ​​described herein. For example, the core can comprise a sintered ceramic material having an average crystallite size in the range of at least 0.01 micron and less than 1 micron, at least 0.03 micron and less than or equal to 0.8 micron, at least 0.05 micron and less than or equal to 0.6 micron, at least 0.08 micron and less than or equal to 0.4 micron, or at least 0.1 micron and less than or equal to 0.2 micron. The average crystallite size can be measured by uncorrected sectioning of SEM micrographs.

[0026] Specific examples of sintered ceramic materials can include alumina (Al2O3), including, for example, microcrystalline alumina (e.g., sol-gel alumina), nanocrystalline alumina, fused alumina such as brown fused alumina, or combinations thereof. In particular, the alumina (Al2O3) can include alpha alumina (α-Al2O3).

[0027] In particular embodiments, the core can include polycrystalline alpha alumina (α-AlO), and more particularly, the polycrystalline alpha alumina (α-AlO) can include an average crystallite size of less than 1 micron, such as those described for sintered ceramic materials. In even more particular embodiments, the core can consist essentially of polycrystalline alpha alumina (α-AlO) including an average crystallite size of less than 1 micron.

[0028] In some embodiments, the core may have a density of at least 80% of theoretical density, e.g., at least 85%, at least 88%, at least 90%, at least 92%, at least 95%, or at least 98% of theoretical density. In other embodiments, the core may have a porosity of 10% or less by volume, based on the total volume of the core, or 9% or less by volume, 8% or less by volume, 7% or less by volume, 6% or less by volume, 5% or less by volume, 4% or less by volume, 3% or less by volume, 2% or less by volume, or 1% or less by volume, based on the total volume of the core. In certain embodiments, the core may be essentially free of porosity. The true density of the core was measured by first measuring the bulk density of the core. The bulk density of the core was measured using a pycnometer (Quantachrome Ultrapycnometer 1000) using ultra-high purity compressed helium adjusted to a pressure of 20 psig. The core was then crushed into powder, and the true density was measured using the pycnometer in the same manner as above. The porosity of the core is calculated by the following formula (porosity = [true density - bulk density] / [true density]).

[0029] In further embodiments, the core can have a density of the sintered ceramic material forming the core. For example, depending on the sintered ceramic material, the core can have a density of at least 2.10 g / cm3 , at least 2.20 g / cm 3 , 2.30g / cm 3 , at least 2.40 g / cm 3 , at least 2.50 g / cm 3 , at least 2.60 g / cm 3 , at least 2.70 g / cm 3 , 2.80g / cm 3 , at least 2.90 g / cm 3 , at least 3.00 g / cm 3 , at least 3.10 g / cm 3 , at least 3.20 g / cm 3 , at least 3.30 g / cm 3 , at least 3.40 g / cm 3 , 3.50g / cm 3 , at least 3.55 g / cm 3 , at least 3.60 g / cm 3 , at least 3.65 g / cm 3 , at least 3.70 g / cm 3 , at least 3.75 g / cm 3 , at least 3.80 g / cm 3 , at least 3.85 g / cm 3 , at least 3.90 g / cm 3 , or at least 3.95 g / cm 3 Additionally or alternatively, the core may have a density of 5.80 g / cm 3 Below, 5.70g / cm 3 Below, 5.60g / cm 3 Below 5.50g / cm 3 Below, 5.40g / cm 3 Below, 5.30g / cm 3 Below, 5.20g / cm 3 Below, 5.10g / cm 3 Below 5.00g / cm 3 , 4.90g / cm 3 Below, 4.80g / cm 3 Below, 4.70g / cm 3 Below, 4.60g / cm 3 Below 4.50g / cm 3 Below, 4.40g / cm 3Below, 4.30g / cm 3 Below 4.20g / cm 3 Below, 4.10g / cm 3 Below 4.00g / cm 3 or less, or 3.97 g / cm 3 It can include the following densities: In further examples, the core can have a density in a range that includes any of the minimum and maximum values ​​stated herein.

[0030] In some embodiments, the core may comprise alumina and one or more of a rare earth oxide, an alkaline earth oxide, or any combination thereof. In some aspects, the core may comprise at least 90 wt. % alumina and a total of 10 wt. % or less of one or more other oxides, based on the total weight of the core. For example, the core may comprise at least 93 wt. % and no more than 98 wt. % alumina, a total of at least 1.5 wt. % and no more than 7 wt. % of one or more rare earth oxides, and up to 2 wt. % of alkaline earth oxides. In other embodiments, the core may comprise a specific content ratio of rare earth oxide to alkaline earth oxide, C RRO / C AEO C RRO is the total content of rare earth oxides, and C AEO is the total content of alkaline earth oxides. For example, C RRO / C AEO The ratio can be at least 1.1, e.g., at least 1.5, at least 1.8, at least 2, at least 2.3, at least 2.5, at least 2.8, at least 3, at least 3.2, at least 3.5, at least 3.7, at least 3.9, or at least 4. In another example, the core has a C of 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, or 5 or less. RRO / C AEO Furthermore, C RRO / C AEO The ratio can be a range that includes any of the minimum and maximum values ​​stated herein.

[0031] In another embodiment, the core may include a specific crystalline structure including a primary crystalline phase including alumina and a secondary magnetoplumbite crystalline phase including an aluminate. In certain embodiments, the core may include a magnetoplumbite crystalline phase including an aluminate including one or more rare earth elements and / or one or more alkaline earth elements. In further embodiments, the core may include La2O3, Y2O3, or a combination thereof. In certain examples, the core may include a higher content of La2O3 than Y2O3. In another example, the core may include at least 1 wt% La2O3 relative to the total weight of the core, e.g., at least 1.5 wt%, at least 2 wt%, at least 2.5 wt%, at least 2.7 wt%, at least 2.8 wt%, at least 3 wt%, at least 3.1 wt%, or at least 3.2 wt% La2O3 relative to the total weight of the core. Additionally or alternatively, the core may comprise 8 wt% or less La2O3, based on the total weight of the core, e.g., 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, or 3.5 wt% or less La2O3, based on the total weight of the core. Further, the core may comprise a La2O3 content ranging from any of the minimum and maximum percentages described herein. In another example, the core may comprise at least 0.3 wt% Y2O3, based on the total weight of the core, e.g., at least 0.4 wt%, at least 0.5 wt%, at least 0.6 wt%, at least 0.7 wt%, at least 0.8 wt%, or at least 0.9 wt% Y2O3, based on the total weight of the core. Additionally or alternatively, the core may comprise 3 wt% or less of Y2O3, based on the total weight of the core, for example, 2.7 wt% or less, 2.5 wt% or less, 2.3 wt% or less, 2 wt% or less, 1.7 wt% or less, 1.5 wt% or less, 1.3 wt% or less, 1.1 wt% or less, or 1 wt% or less of Y2O3, based on the total weight of the core. Further, the core may comprise a Y2O3 content ranging from any of the minimum and maximum percentages described herein. In certain embodiments, the core may comprise a magnetoplumbite crystalline phase comprising an aluminate including La2O3 and Y2O3.

[0032] In one particular embodiment, the core may be essentially free of ZrO2. In at least one other embodiment, the core may include ZrO2. In another particular embodiment, the core may include a secondary magnetoplumbite crystalline phase including MgO. In particular examples, the core may include an MgO content in the range of at least 0.5 wt. % to 2 wt. % based on the total weight of the core, e.g., at least 0.7 wt. % to 1.6 wt. % or at least 0.8 wt. % to 1.4 wt. % based on the total weight of the core.

[0033] In another embodiment, the core can have a specific HV hardness. For example, the core can have an HV hardness of at least 1800, at least 1850, at least 1900, at least 1920, at least 1950, at least 1970, at least 2000, at least 2100, or at least 2200. In another example, the core can have an HV hardness of 2500 or less, e.g., 2400 or less, 2300 or less, 2200 or less, 2100 or less, 2000 or less, 1990 or less, or 1980 or less. Furthermore, the core can have an HV hardness range that includes any of the minimum and maximum values ​​described herein. HV hardness can be determined in accordance with ASTM C1327-15 using a Vickers Hardness Tester LM100AT. Abrasive grain samples can be prepared as follows: Abrasive grains are mounted using a resin to obtain cylindrical test specimens with a diameter of 25 mm. The specimen can be polished to provide a damage-free surface that can be used for hardness testing.

[0034] In one embodiment, the formation process may stop at step 103 with particles having a structure as generally provided in FIG. 2A, including a core 201 and a coating 202, where the coating comprises an inorganic material.

[0035] In an alternative embodiment, the process can proceed after step 103 to step 104, which includes the optional process of applying an organic material. Such a process can occur before incorporating the abrasive particles into the fixed abrasive. According to one embodiment, the process in step 104 includes forming a second portion of the coating (e.g., 203) overlying at least a portion of the first portion of the coating (e.g., 202). In one example, the second portion can include an organic-containing material. In a non-limiting embodiment, the organic-containing material can include a material that can facilitate bonding of the abrasive particles to a bonding material, such as an organic-containing bonding composition (e.g., phenolic resin, epoxy, etc.). In one particular process, the organic-containing material that can be included in the second portion can be a silane-containing material and / or a silanol-containing material. For example, according to the process of FIG. 1, the process in step 104 can include forming a second portion of the coating on the abrasive particles, and such particles can have a general structure as provided in the embodiment of FIG. 2B. References herein to the content of inorganic material, such as the composition from the first portion of the coating 202, are based on the weight percent of the first portion.

[0036] Coating 202 may be in direct contact with core 201. As illustrated, coating 202 may be a layer that covers the entire surface of core 201. In at least one embodiment, coating 202 may cover a majority of the surface of core 201, and a portion of the core surface may not be covered by coating 202. In certain embodiments, the coating may include a dry material. In yet other embodiments, the coating may include an unsintered material.

[0037] In some embodiments, the coating can have a specific percentage ratio of lithium content to silicon content, which can facilitate improved formation and properties of abrasive particles 200 or 210, as illustrated in Figures 2A or 2B, respectively. In some embodiments, the lithium can include a lithium-containing compound. In another aspect, the lithium-containing compound can include an oxide. In yet another embodiment, the lithium-containing compound can include lithium oxide. In some embodiments, the silicon can include a silicon-containing compound. In another aspect, the silicon-containing compound can include an oxide. In yet another embodiment, the silicon-containing compound can include silicon dioxide. In some embodiments, the percent lithium / silicon ratio can be at least 0.02%, or at least 0.03%, or at least 0.04%, or at least 0.05%, or at least 0.06%, or at least 0.07%, or at least 0.08%, at least 0.1%, or at least 0.2%, or at least 0.3%, or at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%, or at least 1.6%, or at least 1.8%, or at least 2.0%, or at least 2.2%, or at least 2.4%, or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%.In still other embodiments, the lithium / silicon percentage ratio can be 250% or less, or 220% or less, or 220% or less, or 180% or less, or 150% or less, or 120% or less, or 100% or less, or 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 43% or less, or 35% or less, or 30% or less, or 25% or less, or 24% or less, or 23% or less, or 22% or less, or 21% or less, or 20% or less, or 19% or less, or 18% or less, or 17% or less, or 16% or less, or 15% or less, or 14% or less, or 13% or less, or 12% or less, or 11% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less. In a further example, the coating can have a lithium / silicon percentage ratio within a range including any of the minimum and maximum values ​​described herein. It will be understood that all of the above ratios are applicable to elemental lithium and elemental silicon, as well as their compounds (including, for example, oxide compounds). For example, the coating can have a lithium oxide / silicon oxide (SiOx) percentage ratio within a range including any of the minimum and maximum values ​​described above for the lithium / silicon percentage ratio. The lithium / silicon percentage ratio is calculated by dividing the weight percentage of lithium in the coating by the weight percentage of silicon in the coating, and then multiplying the calculated number by 100%. The weight percentage is the value obtained by ICP analysis of the coating provided herein. For example, a coating containing 0.9 wt% lithium and 90 wt% silicon would have a lithium / silicon percentage ratio of [(0.9 wt% / 90 wt%) x 100%] = 1%.

[0038] In some embodiments, the coating can have a particular lithium content that can facilitate improved formation and properties of the abrasive particles 200 or 210. In some aspects, the lithium content in the coating is at least 0.01 wt%, or at least 0.02 wt%, or at least 0.03 wt%, or at least 0.04 wt%, or at least 0.05 wt%, or at least 0.06 wt%, or at least 0.07 wt%, or at least 0.08 wt%, or at least 0.09 wt%, or at least 0.1 wt%, or at least 0.15 wt%, or at least 0.2 wt%, or at least 0.23 wt%, or at least 0.25 wt%, or at least 0.3 wt%, or at least 0.35 wt%, or at least 0.4 wt%, or at least 0.5 wt%, based on the total weight of the coating. %, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.1%, or at least 1.2%, or at least 1.3%, or at least 1.4%, or at least 1.5%, or at least 1.6%, or at least 1.7%, or at least 1.8%, or at least 1.9%, or at least 2.0%, or at least 2.1%, or at least 2.2%, or at least 2.3%, at least 2.4%, or at least 2.5%, or at least 2.6% by weight. In still other embodiments, the lithium content can be 20 wt% or less, or 19 wt% or less, or 18 wt% or less, or 17 wt% or less, or 16 wt% or less, or 15 wt% or less, or 14 wt% or less, or 13 wt% or less, or 12 wt% or less, or 11 wt% or less, or 10 wt% or less, or 9 wt% or less, or 8 wt% or less, or 7 wt% or less, or 6 wt% or less, or 5 wt% or less, or 4 wt% or less, or 3 wt% or less, or 2 wt% or less, or 1.8 wt% or less, based on the total weight of the coating. It will be understood that the coating can have a lithium content within a range including any of the minimum and maximum values ​​stated herein.As will be understood, the weight percent of lithium is calculated according to ICP analytical techniques as described herein, and weight percent of lithium is intended to refer to weight percent of elemental lithium.

[0039] In some embodiments, the coating can have a content of a particular lithium-containing material that can facilitate improved formation and properties of the abrasive particles 200 or 210. In some aspects, the content of the lithium-containing material in the coating is at least 0.01 wt.% based on the total weight of the coating, or at least 0.02 wt.%, or at least 0.03 wt.%, or at least 0.04 wt.%, or at least 0.05 wt.%, or at least 0.06 wt.%, or at least 0.07 wt.%, or at least 0.08 wt.%, or at least 0.09 wt.%, or at least 0.1 wt.%, or at least 0.15 wt.%, or at least 0.2 wt.%, or at least 0.23 wt.%, or at least 0.25 wt.%, or at least 0.3 wt.%, or at least 0.35 wt.%, or at least 0.4 wt.%, or It may be at least 0.5% by weight, or at least 0.6% by weight, or at least 0.7% by weight, or at least 0.8% by weight, or at least 0.9% by weight, or at least 1.0% by weight, or at least 1.1% by weight, or at least 1.2% by weight, or at least 1.3% by weight, or at least 1.4% by weight, or at least 1.5% by weight, or at least 1.6% by weight, or at least 1.7% by weight, or at least 1.8% by weight, or at least 1.9% by weight, or at least 2.0% by weight, or at least 2.1% by weight, or at least 2.2% by weight, or at least 2.3% by weight, at least 2.4% by weight, or at least 2.5% by weight, or at least 2.6% by weight. In still other embodiments, the lithium-containing material content can be 20 wt% or less, based on the total weight of the coating, or 19 wt% or less, or 18 wt% or less, or 17 wt% or less, or 16 wt% or less, or 15 wt% or less, or 14 wt% or less, or 13 wt% or less, or 12 wt% or less, or 11 wt% or less, or 10 wt% or less, or 9 wt% or less, or 8 wt% or less, or 7 wt% or less, or 6 wt% or less, or 5 wt% or less, or 4 wt% or less, or 3 wt% or less, or 2 wt% or less, based on the total weight of the coating.It will be understood that the coating can have a lithium-containing material content within a range including any of the minimum and maximum values ​​described herein. In certain embodiments, the coating can have a particular lithium oxide and / or lithium silicate content that can facilitate improved formation and properties of the abrasive particles 200. For example, the lithium-containing material content described in embodiments herein can apply to lithium oxide and / or lithium silicate.

[0040] In yet another embodiment, the coating can have a specific percentage ratio of potassium content to silicon content that can facilitate improved formation and properties of the abrasive particles 200 or 210. In some embodiments, the potassium can include a potassium-containing compound. In another aspect, the potassium-containing compound can include an oxide. In yet another embodiment, the potassium-containing compound can include potassium oxide. In some embodiments, the silicon can include a silicon-containing compound. In another aspect, the silicon-containing compound can include an oxide. In yet another embodiment, the silicon-containing compound can include silicon dioxide. In some aspects, the percentage ratio of potassium / silicon is at least 0.01%, or at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, at least 0.1%, or at least 0.2%, or at least 0.3%, or at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least In any case, the solubility of the cellulose in the cellulose membrane is at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%, or at least 1.6%, or at least 1.8%, or at least 2.0%, or at least 2.2%, or at least 2.4%, or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.1%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%.In yet other embodiments, the potassium / silicon percentage ratio is 40% or less, or 39% or less, or 38% or less, or 37% or less, or 36% or less, or 35% or less, or 34% or less, or 33% or less, or 32% or less, or 31% or less, or 30% or less, or 29% or less, or 28% or less, or 27% or less, or 26% or less, or 25% or less, or 24% or less, or 23% or less, or 22% or less, or 21% or less, or 20% or less, or 1 9% or less, or 18% or less, or 17% or less, or 16% or less, or 15% or less, or 14% or less, or 13% or less, or 12% or less, or 11% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less, or 2% or less, or 2% or less, or 1% or less, or 0.9% or less, or 0.8% or less, or 0.7% or less, or 0.6% or less, or 0.5% or less, or 0.4% or less. In further examples, the coating can have a potassium / silicon percentage ratio within a range including any of the minimum and maximum values ​​described herein. It will be understood that all of the above ratios are applicable to elemental potassium and silicon, and compounds thereof (including, for example, oxide compounds). For example, the coating can have a potassium oxide / silicon oxide (SiOx) percentage ratio within a range including any of the minimum and maximum values ​​for the potassium / silicon percentage ratio described above. The potassium / silicon percentage ratio is calculated by dividing the weight percentage of potassium in the coating by the weight percentage of silicon in the coating, and then multiplying the calculated number by 100%. The weight percentage is the value obtained by ICP analysis of the coating provided herein. For example, a coating containing 0.9 wt% potassium and 90 wt% silicon would have a potassium / silicon percentage ratio of [(0.9 wt% / 90 wt%) x 100%] = 1%.

[0041] In another embodiment, the coating can have a particular silicon content that can facilitate improved formation and properties of the abrasive particles 200 or 210 . In some embodiments, the silicon content is at least 21 wt% based on the total weight of the coating, e.g., at least 25 wt%, or at least 30 wt%, or at least 32 wt%, or at least 33 wt%, or at least 35 wt%, or at least 37 wt%, or at least 38 wt%, or at least 40 wt%, or at least 41 wt%, or at least 42 wt%, or at least 43 wt%, or at least 44 wt%, or at least 45 wt%, or at least 46 wt%, or at least 48 wt%, or at least 50 wt%, or at least 52 wt%, or at least 55 wt%, or at least 60 wt%, or at least 65 wt%, or at least 70 wt%, or at least 75 wt%, or at least 80 wt%, or at least 85 wt%, or at least 90 wt%, or at least 92 wt%, or at least 95 wt% based on the total weight of the coating, such as first portion 202 of the coating. In still other non-limiting embodiments, the silicon content can be 99% by weight or less, or 98% by weight or less, or 97% by weight or less, or 96% by weight or less, or 95% by weight or less, or 93% by weight or less, or 90% by weight or less, or 88% by weight or less, or 85% by weight or less, or 83% by weight or less, or 80% by weight or less, or 77% by weight or less, or 75% by weight or less, or 72% by weight or less, or 68% by weight or less, or 64% by weight or less, or 61% by weight or less, or 58% by weight or less, or 56% by weight or less, or 54% by weight or less, or 53% by weight or less, or 51% by weight or less, or 50% by weight or less, or 49% by weight or less, or 48% by weight or less, or 46% by weight or less, or 45% by weight or less, or 44% by weight or less, based on the total weight of the coating. In further examples, the coating can have a silicon content within a range including any of the minimum and maximum values ​​described herein. For example, the coating may have a silicon content ranging from at least 21% to no more than 77% by weight, or ranging from at least 33% to no more than 61% by weight, or ranging from at least 38% to no more than 52% by weight.As will be understood, weight percent silicon is calculated according to ICP analytical techniques as described herein and is intended to refer to weight percent of elemental silicon.

[0042] In another embodiment, the coating can have a content of certain silicon-containing compounds that can facilitate improved formation and properties of the abrasive particles 200 or 210 . In some embodiments, the content of the silicon-containing compound can be at least 21 wt.% based on the total weight of the coating, for example, at least 25 wt.%, or at least 30 wt.%, or at least 32 wt.%, or at least 33 wt.%, or at least 35 wt.%, or at least 37 wt.%, or at least 38 wt.%, or at least 40 wt.%, or at least 41 wt.%, or at least 42 wt.%, or at least 43 wt.%, or at least 44 wt.%, or at least 45 wt.%, or at least 46 wt.%, or at least 48 wt.%, or at least 50 wt.%, or at least 52 wt.%, or at least 55 wt.%, or at least 60 wt.%, or at least 65 wt.%, or at least 70 wt.%, or at least 75 wt.%, or at least 80 wt.%, or at least 85 wt.%, or at least 90 wt.%, or at least 92 wt.%, or at least 95 wt.% based on the total weight of the coating, such as the first portion 202 of the coating. In still other non-limiting embodiments, the content of the silicon-containing compound can be 99% by weight or less, or 98% by weight or less, or 97% by weight or less, or 96% by weight or less, or 95% by weight or less, or 93% by weight or less, or 90% by weight or less, or 88% by weight or less, or 85% by weight or less, or 83% by weight or less, or 80% by weight or less, or 77% by weight or less, or 75% by weight or less, or 72% by weight or less, or 68% by weight or less, or 64% by weight or less, or 61% by weight or less, or 58% by weight or less, or 56% by weight or less, or 54% by weight or less, or 53% by weight or less, or 51% by weight or less, or 50% by weight or less, or 49% by weight or less, or 48% by weight or less, or 46% by weight or less, or 45% by weight or less, or 44% by weight or less, based on the total weight of the coating. In further examples, the coating can have a silicon-containing compound content within a range including any of the minimum and maximum values ​​described herein. In another embodiment, the coating may include silicon oxide (SiOx) in any of the contents described for the silicon-containing compounds.

[0043] In another embodiment, the coating can have a particular oxygen content that can facilitate improved formation and properties of the abrasive particles 200 or 210. In one aspect, the oxygen content can be at least 32% by weight, or at least 33% by weight, or at least 35% by weight, or at least 37% by weight, or at least 38% by weight, or at least 40% by weight, or at least 41% by weight, or at least 42% by weight, or at least 43% by weight, or at least 44% by weight, or at least 45% by weight, or at least 46% by weight, or at least 48% by weight, or at least 50% by weight, or at least 52% by weight, or at least 55% by weight, or at least 60% by weight, or at least 65% by weight, or at least 70% by weight, or at least 75% by weight, or at least 80% by weight, or at least 85% by weight, or at least 90% by weight, or at least 92% by weight, or at least 95% by weight, based on the total weight of the coating. In still other non-limiting embodiments, the oxygen content can be 99% by weight or less, or 98% by weight or less, or 97% by weight or less, or 96% by weight or less, or 95% by weight or less, or 93% by weight or less, or 90% by weight or less, or 88% by weight or less, or 85% by weight or less, or 83% by weight or less, or 80% by weight or less, or 77% by weight or less, or 75% by weight or less, or 72% by weight or less, or 68% by weight or less, or 64% by weight or less, or 61% by weight or less, or 58% by weight or less, or 56% by weight or less, or 54% by weight or less, or 53% by weight or less, or 51% by weight or less, or 50% by weight or less, or 49% by weight or less, or 48% by weight or less, or 46% by weight or less, or 45% by weight or less, or 44% by weight or less, based on the total weight of the coating. In further examples, the coating can have an oxygen content within a range including any of the minimum and maximum values ​​described herein. For example, the coating may include an oxygen content ranging from at least 21% to no more than 77% by weight, inclusive, or at least 33% to no more than 65% by weight, inclusive. As will be understood, the weight percent of oxygen is calculated according to ICP analytical techniques as described herein and is intended to refer to the weight percent of elemental oxygen.In another embodiment, the coating can have a specific potassium content that can facilitate improved formation and properties of the abrasive particles 200. In one aspect, the potassium content can be at least 0.01 wt%, or at least 0.02 wt%, or at least 0.03 wt%, or at least 0.04 wt%, or at least 0.05 wt%, or at least 0.06 wt%, or at least 0.07 wt%, or at least 0.08 wt%, or at least 0.09 wt%, or at least 1 wt%, e.g., at least 2 wt%, or at least 3 wt%, or at least 4 wt%, or at least 5 wt%, or at least 6 wt%, or at least 7 wt%, or at least 8 wt%, or at least 9 wt%, or at least 10 wt%, based on the total weight of the coating. In still other embodiments, the potassium content is 30% by weight or less, 29% by weight or less, or 28% by weight or less, or 27% by weight or less, or 26% by weight or less, or 25% by weight or less, or 24% by weight or less, or 23% by weight or less, or 22% by weight or less, or 21% by weight or less, or 20% by weight or less, or 19% by weight or less, or 18% by weight or less, or 17% by weight or less, or 16% by weight or less, or 15% by weight or less, or 14% by weight or less, or 13% by weight or less, or 12% by weight or less, based on the total weight of the coating. The potassium content may be 11% by weight or less, or 10% by weight or less, or 9% by weight or less, or 8% by weight or less, or 7% by weight or less, or 6% by weight or less, or 5% by weight or less, or 4% by weight or less, or 3% by weight or less, or 2% by weight or less, or 1% by weight or less, or 0.9% by weight or less, or 0.8% by weight or less, or 0.7% by weight or less, or 0.6% by weight or less, or 0.5% by weight or less, or 0.4% by weight or less, or 0.3% by weight or less, or 0.2% by weight or less, or 0.1% by weight or less, or 0.05% by weight or less. In a further example, the coating may have a potassium content within a range including any of the minimum and maximum values ​​described herein. In at least one particular embodiment, the coating may be essentially free of potassium. In yet another particular embodiment, potassium may be an unavoidable impurity present in the coating.For example, potassium in the coating may result from the use of starting materials containing impurities, including potassium-containing materials. As will be understood, the weight percent of potassium is calculated according to ICP analytical techniques as described herein and is intended to refer to the weight percent of elemental potassium.

[0044] In yet another embodiment, the coating can have a specific percentage ratio of sodium content to silicon content, which can facilitate improved formation and properties of the abrasive particle 200. In some embodiments, the sodium can include a sodium-containing compound. In another aspect, the sodium-containing compound can include an oxide. In yet another embodiment, the sodium-containing compound can include sodium oxide. In some embodiments, the silicon can include a silicon-containing compound. In another aspect, the silicon-containing compound can include an oxide. In yet another embodiment, the silicon-containing compound can include silicon dioxide. In some embodiments, the sodium / silicon percentage ratio is at least 0.01%, or at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, or at least 0.1%, or at least 0.2%, or at least 0.3%, or at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%. , or at least 1.6%, or at least 1.8%, or at least 2.0%, or at least 2.2%, or at least 2.4%, or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%, or at least 4.2%, or at least 4.4%, or at least 4.6%, or at least 4.8%, or at least 5.0%, or at least 5.2%, or at least 5.4%, or at least 5.5%.In yet other embodiments, the sodium / silicon percentage ratio is 40% or less, or 39% or less, or 38% or less, or 37% or less, or 36% or less, or 35% or less, or 34% or less, or 33% or less, or 32% or less, or 31% or less, or 30% or less, or 29% or less, or 28% or less, or 27% or less, or 26% or less, or 25% or less, or 24% or less, or 23% or less, or 22% or less, The sodium / silicon ratio may be 21% or less, or 20% or less, or 19% or less, or 18% or less, or 17% or less, or 16% or less, or 15% or less, or 14% or less, or 13% or less, or 12% or less, or 11% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less, or 2.5% or less, or 2.3% or less, or 2% or less, or 1% or less, or 0.5% or less. In a further example, the coating may have a sodium / silicon percentage ratio within a range including any of the minimum and maximum values ​​described herein. It will be understood that all of the above ratios are applicable to elemental sodium and silicon, as well as their compounds (e.g., including oxide compounds). For example, the coating may have a sodium oxide / silicon oxide (SiOx) percentage ratio within a range including any of the minimum and maximum values ​​described above for the sodium / silicon percentage ratio. The sodium / silicon percentage ratio is calculated by dividing the weight percentage of sodium in the coating by the weight percentage of silicon in the coating, and then multiplying the calculated number by 100%. The weight percentage is the value obtained by ICP analysis of the coating provided herein. For example, a coating containing 0.9 wt% sodium and 90 wt% silicon would have a sodium / silicon percentage ratio of [(0.9 wt% / 90 wt%) x 100%] = 1%.

[0045] In another embodiment, the coating can have a particular sodium content that can facilitate improved formation and properties of the abrasive particles 200. In one aspect, the sodium content can be at least 0.1 wt.%, e.g., at least 0.2 wt.%, or at least 0.3 wt.%, or at least 0.4 wt.%, or at least 0.5 wt.%, or at least 0.6 wt.%, or at least 0.7 wt.%, or at least 0.8 wt.%, or at least 0.9 wt.%, or at least 1 wt.%, or at least 1.5 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 4 wt.%, or at least 5 wt.%, or at least 6 wt.%, or at least 7 wt.%, or at least 8 wt.%, or at least 9 wt.%, or at least 10 wt.%, based on the total weight of the coating. In still other embodiments, the sodium content may be 20 wt% or less, or 19 wt% or less, or 18 wt% or less, or 17 wt% or less, or 16 wt% or less, or 15 wt% or less, or 14 wt% or less, or 13 wt% or less, or 12 wt% or less, or 11 wt% or less, or 10 wt% or less, or 8 wt% or less, or 6 wt% or less, or 4 wt% or less, or 2.5 wt% or less, or 2 wt% or less, or 1.5 wt% or less, or 1.2 wt% or less, based on the total weight of the coating. In further examples, the coating may have a sodium content within a range including any of the minimum and maximum values ​​described herein. In other examples, the coating may include a sodium content of at least 0.1 wt% and 16 wt% or less, inclusive, or at least 0.3 wt% and 9 wt% or less, inclusive, or at least 0.5 wt% and 1.2 wt% or less. In at least one specific embodiment, sodium may be present among impurities included in the coating. For example, sodium-containing materials may be unavoidable impurities contained in the starting materials, resulting in the presence of sodium in the coating. In one particular embodiment, the coating may be essentially free of sodium. In another particular embodiment, the coating may be essentially free of sodium.As will be understood, weight percent sodium is calculated according to ICP analytical techniques as described herein and is intended to refer to weight percent of elemental sodium.

[0046] According to another non-limiting embodiment, the coating can have a particular percentage ratio of sodium content to lithium content that can facilitate improved formation and properties of the abrasive particle 200. In certain aspects, the percentage ratio of sodium / lithium is at least 0.01%, or at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, or at least 0.1%, or at least 0.2%, or at least 0.3%, or at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%, or at least 1.6%, or at least 1.8%, or at least 2.0%, or at least 2.2%, or at least 2.4%, or less. or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%, or at least 6%, or at least 8%, or at least 10%, or at least 13%, or at least 16%, or at least 20%, or at least 24%, or at least 28%, or at least 31%, or at least 35%, or at least 39%, or at least 43%, or at least 45%, or at least 47%, or at least 48%, or at least 50%, or at least 52%, or at least 54%, or at least 56%, or at least 58%, or at least 61%.In still other embodiments, the sodium / lithium percentage ratio is 600% or less, or 550% or less, or 530% or less, or 510% or less, or 490% or less, or 470% or less, or 450% or less, or 430% or less, or 420% or less, or 400% or less, or 350% or less, or 320% or less, or 300% or less, or 250% or less, or 200% or less, or 100% or less, or 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less, or 15% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less. In further examples, the coating can have a sodium / silicon percentage ratio within a range including any of the minimum and maximum values ​​described herein. In certain examples, the coating can have a sodium / silicon percentage ratio within a range including at least 4.0% and not more than 600%, or within a range including at least 35% and not more than 500%, or within a range including at least 47% and not more than 420%. The sodium / lithium percentage ratio is calculated by dividing the weight percentage of sodium in the coating by the weight percentage of lithium in the coating, and then multiplying the calculated number by 100%. The weight percentage is the value obtained by ICP analysis of the coating provided herein. For example, a coating containing 0.9 wt% sodium and 90 wt% lithium would have a sodium / lithium percentage ratio of [(0.9 wt% / 90 wt%) x 100%] = 1%.

[0047] According to another non-limiting embodiment, the coating can have a particular percentage ratio of sodium content to potassium content that can facilitate improved formation and properties of the abrasive particle 200. In certain aspects, the percentage ratio of sodium / potassium is at least 0.01%, or at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, or at least 0.1%, or at least 0.2%, or at least 0.3%, or at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%, or at least or at least 1.6%, or at least 1.8%, or at least 2.0%, or at least 2.2%, or at least 2.4%, or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%, or at least 5.0%, or at least 8.0%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%. In still other embodiments, the sodium / potassium percentage ratio is 200% or less, or 190% or less, or 180% or less, or 170% or less, or 60% or less, or 150% or less, or 140% or less, or 130% or less, or 120% or less, or 110% or less, or 100% or less, or 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less, or 15% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less. In further examples, the coating can have a sodium / potassium percentage ratio within a range including any of the minimum and maximum values ​​described herein.The sodium / potassium percentage ratio is calculated by dividing the weight percentage of sodium in the coating by the weight percentage of potassium in the coating, then multiplying the calculated number by 100%. The weight percentages are values ​​obtained by ICP analysis of the coatings provided herein. For example, a coating containing 0.9 wt% sodium and 90 wt% potassium would have a sodium / potassium percentage ratio of [(0.9 wt% / 90 wt%) x 100%] = 1%.

[0048] According to another non-limiting embodiment, the coating can have a particular percentage ratio of potassium content to lithium content that can facilitate improved formation and properties of the abrasive particle 200. In certain aspects, the percentage ratio of potassium / lithium is at least 0.01%, or at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, or at least 0.1%, or at least 0.2%, or at least 0.3%, or at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%, or at least or at least 1.6%, or at least 1.8%, or at least 2.0%, or at least 2.2%, or at least 2.4%, or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%, or at least 5.0%, or at least 8.0%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%. In still other embodiments, the potassium / lithium percentage ratio is 200% or less, or 190% or less, or 180% or less, or 170% or less, or 60% or less, or 150% or less, or 140% or less, or 130% or less, or 120% or less, or 110% or less, or 100% or less, or 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less, or 15% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less. In further examples, the coating can have a potassium / lithium percentage ratio within a range including any of the minimum and maximum values ​​described herein.The potassium / lithium percentage ratio is calculated by dividing the weight percentage of potassium in the coating by the weight percentage of lithium in the coating, then multiplying the calculated number by 100%. The weight percentages are values ​​obtained by ICP analysis of the coatings provided herein. For example, a coating containing 0.9 wt% potassium and 90 wt% lithium would have a potassium / lithium percentage ratio of [(0.9 wt% / 90 wt%) x 100%] = 1%.

[0049] In yet other embodiments, the coating can have a particular sodium content relative to the lithium content, which can facilitate improved formation and properties of the abrasive particle 200. In certain aspects, the coating includes a sodium content that is 10 times or less than the lithium content, as measured in weight percent by the ICP analytical techniques described herein, or the coating includes a sodium content that is 8 times or less than the lithium content, or the coating includes a sodium content that is 6 times or less than the lithium content, or the coating includes a sodium content that is 4 times or less than the lithium content, or the coating includes a sodium content that is 3 times or less than the lithium content, or the coating includes a sodium content that is 2.8 times or less than the lithium content, or the coating includes a sodium content that is 2.5 times or less than the lithium content, or the coating includes a sodium content that is 2.2 times or less than the lithium content, or the coating includes a sodium content that is 2 times or less than the lithium content, or the coating contains a sodium content that is less than or equal to 1.8 times the lithium content, or the coating contains a sodium content that is less than or equal to 1.5 times the lithium content, or the coating contains a sodium content that is less than or equal to 1.3 times the lithium content, or the coating contains a sodium content that is less than or equal to 0.9 times the lithium content, or the coating contains a sodium content that is less than or equal to 0.6 times the lithium content, or the coating contains a sodium content that is less than or equal to 0.3 times the lithium content, or the coating contains a sodium content that is less than or equal to 0.2 times the lithium content, or the coating contains a sodium content that is less than or equal to 0.1 times the lithium content, or the coating contains a sodium content that is less than or equal to 0.05 times the lithium content, or the coating contains a sodium content that is less than or equal to 0.01 times the lithium content.

[0050] In yet other embodiments, the coating can have a particular sodium content relative to the potassium content, which can facilitate improved formation and properties of the abrasive particle 200. In certain aspects, the coating includes a sodium content that is 10 times or less than the potassium content, as measured in weight percent by the ICP analytical techniques described herein, or the coating includes a sodium content that is 8 times or less than the potassium content, or the coating includes a sodium content that is 6 times or less than the potassium content, or the coating includes a sodium content that is 4 times or less than the potassium content, or the coating includes a sodium content that is 3 times or less than the potassium content, or the coating includes a sodium content that is 2.8 times or less than the potassium content, or the coating includes a sodium content that is 2.5 times or less than the potassium content, or the coating includes a sodium content that is 2.2 times or less than the potassium content, or the coating includes a sodium content that is 2 times or less than the potassium content, or the coating contains a sodium content that is 1.8 times or less than the potassium content, or the coating contains a sodium content that is 1.5 times or less than the potassium content, or the coating contains a sodium content that is 1.3 times or less than the potassium content, or the coating contains a sodium content that is 0.9 times or less than the potassium content, or the coating contains a sodium content that is 0.6 times or less than the potassium content, or the coating contains a sodium content that is 0.3 times or less than the potassium content, or the coating contains a sodium content that is 0.2 times or less than the potassium content, or the coating contains a sodium content that is 0.1 times or less than the potassium content, or the coating contains a sodium content that is 0.05 times or less than the potassium content, or the coating contains a sodium content that is 0.01 times or less than the potassium content.

[0051] In another embodiment, the coating can have a content of a specific silicate-containing compound that can facilitate improved formation and performance of the abrasive particles 200. In certain embodiments, the silicate-containing compound can include potassium silicate, sodium silicate, lithium silicate, or a combination thereof. In some aspects, the content of the silicate-containing compound is at least 1 wt%, or at least 5 wt%, or at least 10 wt%, or at least 15 wt%, or at least 20 wt%, or at least 30 wt%, or at least 40 wt%, or at least 50 wt%, or at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or at least 90 wt%, based on the total weight of the coating. In still other embodiments, the content of the silicate-containing compound is 99 wt% or less based on the total weight of the coating, or 95 wt% or less, or 90 wt% or less, or 80 wt% or less, or 70 wt% or less, or 60 wt% or less, or 50 wt% or less, or 40 wt% or less, or 30 wt% or less, or 20 wt% or less, or 10 wt% or less based on the total weight of the coating. In a further example, the coating can have a silicate-containing compound content within a range including any of the minimum and maximum values ​​described herein, where it is understood that the weight percent of the silicate-containing compound is calculated according to ICP analytical techniques as described herein.

[0052] In another embodiment, the coating can have a content of a specific silica-containing compound that can facilitate improved formation and properties of the abrasive particles 200. In certain embodiments, the silica-containing compound can include silicon dioxide or a combination thereof. In some aspects, the content of the silica-containing compound is at least 1 wt.%, or at least 5 wt.%, or at least 10 wt.%, or at least 15 wt.%, or at least 20 wt.%, or at least 30 wt.%, or at least 40 wt.%, or at least 50 wt.%, or at least 60 wt.%, or at least 70 wt.%, or at least 80 wt.%, or at least 90 wt.% based on the total weight of the coating. In still other embodiments, the content of the silica-containing compound is 99 wt.% or less based on the total weight of the coating, or 95 wt.% or less, or 90 wt.% or less, or 80 wt.% or less, or 70 wt.% or less, or 60 wt.% or less, or 50 wt.% or less, or 40 wt.% or less, or 30 wt.% or less, or 20 wt.% or less, or 10 wt.% or less based on the total weight of the coating. In a further example, the coating can have a silica-containing compound content within a range including any of the minimum and maximum values ​​described herein, where it is understood that the weight percent of the silica-containing compound is calculated according to ICP analytical techniques as described herein.

[0053] According to another non-limiting embodiment, the coating can have a particular percentage ratio of silicate content to silica content that can facilitate improved formation and properties of the abrasive particle 200. In some aspects, the percentage ratio of silicate / silica is at least 10%, or at least or at least 15%, or at least 20%, or at least 25%, or at least 30%, or at least 35%, or at least 40%, or at least 45%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 100%. In still other embodiments, the silicate / silica percentage ratio is 1000% or less, or 900% or less, or 800% or less, or 700% or less, or 600% or less, or 500% or less, or 400% or less, or 300% or 200% or less, or 190% or less, or 180% or less, or 170% or less, or 60% or less, or 150% or less, or 140% or less, or 130% or less, or 120% or less, or 110% or less, or 100% or less, or 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less, or 15% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less. In a further example, the coating can have a silicate / silica percentage ratio within a range including any of the minimum and maximum values ​​described herein. The silicate / silica percentage ratio is calculated by dividing the weight percentage of silicate-containing compounds in the coating by the weight percentage of silica-containing compounds in the coating, and then multiplying the calculated number by 100%. The weight percentage is the value obtained by ICP analysis of the coatings provided herein. For example, a coating containing 0.9 wt% silicate-containing compounds and 90 wt% silica-containing compounds would have a silicate / silica percentage ratio of [(0.9 wt% / 90 wt%) x 100%] = 1%.

[0054] In some embodiments, the abrasive particle 200 can have an average coating coverage on the surface of the core 201, which can facilitate improved properties and performance of the abrasive particle. In some aspects, the average coating coverage can be at least 50% of the total surface of the core, at least 55%, at least 57%, at least 59%, at least 61%, at least 63%, at least 65%, at least 68%, at least 70%, at least 72%, at least 75%, at least 76%, at least 77%, at least 79%, at least 80%, at least 82%, at least 84%, at least 85%, at least 87%, at least 88%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, and at least 98%, at least 99%, and up to 100% of the total surface of the core 201.

[0055] In some embodiments, the abrasive particles may include a coating containing an alkali metal element including lithium, silicon, oxygen, or any combination thereof. In particular embodiments, the coating may include a silicon content higher than that of lithium. In another particular embodiment, the coating may include an oxygen content higher than that of lithium. In yet another particular embodiment, the coating may include lithium, silicon, and oxygen. For example, the coating may include a lithium-containing material. In a more particular example, the coating may include a lithium-containing material including at least one of silicon and oxygen. In an even more particular example, the coating may include a lithium-containing material including silicon and oxygen.

[0056] The coating coverage can be determined by energy dispersive spectroscopy (EDS) analysis. Image acquisition of the abrasive particles can be performed using a Zeiss Merlin™ field emission scanning electron microscope (FESEM) with suitable imaging parameters and Bruker software Fast Acquisition. For example, parameters of 7 kV, 300 pA, and a maximum WD of 10 mm can be used for imaging. Prior to image acquisition, the abrasive particles can be coated with Au / Pd for 30 seconds. EDS can be used to quantify the elements of the abrasive particles and to indicate whether a point on the core is covered by the first moiety. 1% Si can be used as the 1% Si threshold, and the quantitative chemical analysis for each point can be reduced to a binary value (covered or not). The amount of Au / Pd coating and C element are not considered in the analysis. To calculate the reported confidence intervals, one can use the 95% confidence interval (95% CI) on a binomial distribution calculator, such as the Binomial Probability Confidence Interval Calculator (version 4.0), available at www.dianelsoper.com. For example, if 53 of 60 points show an SI greater than 1%, the number of trials to enter into the calculator is 60, with 53 being successful. With a 95% CI, coverage is 77% to 95%.

[0057] In another embodiment, coating 202 can have a substantially uniform thickness. In one embodiment, the thickness of coating 202 can vary along the surface of core 201.

[0058] In another embodiment, the abrasive particle 200 can have an average thickness of the coating 202, which can facilitate improved formation and properties of the abrasive particle. For example, the average thickness of the coating 202 can be at least 10 nm, at least 12 nm, at least 15 nm, at least 18 nm, at least 20 nm, at least 25 nm, at least 28 nm, at least 30 nm, at least 32 nm, at least 35 nm, at least 38 nm, at least 40 nm, at least 43 nm, at least 45 nm, at least 48 nm, at least 50 nm, at least 52 nm, at least 55 nm, at least 58 nm, at least 60 nm, at least 63 nm, at least 68 nm, at least 70 nm, at least 74 nm, at least 76 nm, at least 80 nm, at least 83 nm, at least 86 nm, or at least 90 nm. In another example, the average thickness of the coating 202 of the abrasive particle 200 can be 150 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, 110 nm or less, or 100 nm or less. Additionally, the average thickness of the coating 202 of the abrasive particle 200 can be in a range that includes any of the minimum and maximum values ​​described herein. For example, the abrasive particle can include an average thickness of the coating 202 in the range of 10 nm to 150 nm, or in the range of 80 nm to 100 nm.

[0059] In further embodiments, the abrasive particle 200 can include a particular thickness standard deviation of the coating 202, which can facilitate improved formation of the abrasive particle and improved performance of the abrasive particle. In some embodiments, the absolute value of the thickness standard deviation can be 200% or less of the average thickness, 150% or less, 100% or less, 80% or less, 50% or less, 49% or less, 47% or less, 44% or less, 42% or less, 40% or less, 38% or less, 36% or less, 34% or less, 33% or less, 31% or less, 30% or less, 29% or less, 27% or less, 25% or less, 23% or less, 21% or less, 20% or less, 19% or less, 18% or less, 17% or less, 16% or less, 14% or less, 12% or less, 11% or less, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.8% or less, 0.7% or less, or 0.5% or less of the average thickness of the coating. In another embodiment, the abrasive particles can comprise an absolute value of a thickness standard deviation of at least 0.001% of the average thickness, at least 0.05%, at least 0.08%, at least 0.1%, at least 0.2%, at least 0.3%, at least 0.4%, at least 0.5%, at least 0.7%, at least 0.8%, at least 0.9%, at least 1%, at least 1.2%, at least 1.5%, at least 1.8%, at least 2%, at least 2.2%, at least 2.5%, at least 2.8%, at least 3%, at least 4%, or at least 5% of the average thickness of the coating. Further, the abrasive particles can comprise a thickness standard deviation of the coating having an absolute value in a range including any of the minimum and maximum values ​​described herein.

[0060] In further embodiments, the abrasive particles have a diameter of at least 1 nm, at least 3 nm, at least 5 nm, at least 7 nm, at least 9 nm, at least 10 nm, at least 13 nm, at least 15 nm, at least 17 nm, at least 19 nm, at least 21 nm, at least 23 nm, at least 25 nm, at least 28 nm, at least 30 nm, at least 32 nm, at least 34 nm, at least 36 nm, at least 39 nm, at least 41 nm, at least 45 nm, at least 46 nm, at least 48 nm, or at least 50 nm. The coating 202 may have a thickness standard deviation of at least 60 nm, at least 70 nm, at least 80 nm, at least 100 nm, at least 110 nm, at least 120 nm, at least 130 nm, at least 140 nm, at least 150 nm, at least 160 nm, at least 170 nm, at least 180 nm, at least 190 nm, at least 210 nm, at least 220 nm, or at least 230 nm, at least 240 nm, at least 250 nm, at least 260 nm, at least 270 nm, or at least 280 nm. In another embodiment, the thickness standard deviation can be 500 nm or less, 480 nm or less, 460 nm or less, 420 nm or less, 400 nm or less, 350 nm or less, 320 nm or less, 310 nm or less, 300 nm or less, 280 nm or less, 260 nm or less, 230 nm or less, 210 nm or less, 190 nm or less, 170 nm or less, 150 nm or less, 130 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less, 18 nm or less, 15 nm or less, 12 nm or less, 10 nm or less, or 5 nm or less. Furthermore, the thickness standard deviation of the coating can be in a range that includes any of the minimum and maximum values ​​described herein. In particular examples, the coating thickness standard deviation may be in the range of 10 nm to 400 nm, or in the range of 30 nm to 300 nm, or in the range of 50 nm to 200 nm.

[0061] In some embodiments, coating 202 can include an amorphous phase that includes silica. In another particular aspect, coating 202 can include a certain amount of amorphous phase that can facilitate the formation and improved properties of abrasive grains 210 and abrasive articles including abrasive grains 210. For example, at least 90% by volume, or at least 95% by volume, of coating 202 can be amorphous phase. In further particular aspects, coating 202 consists essentially of amorphous phase.

[0062] In another embodiment, coating 202 can include silica in an amorphous phase and a crystalline phase. In another particular embodiment, coating 202 can include an amorphous phase consisting essentially of silica and a crystalline phase consisting essentially of silica.

[0063] In some aspects, the coating, particularly the first portion 202 of the coating, can have a specific crystalline content that can improve the manufacture and / or performance of abrasive particles and / or fixed abrasive articles containing such abrasive particles. For example, the coating may have a specific crystalline content (i.e., single crystal or polycrystalline), including, for example and without limitation, a crystalline content of at least 1% by volume of the total volume of the first portion 202, such as at least 3% by volume, or at least 5% by volume, or at least 7% by volume, or at least 10% by volume, or at least 12% by volume, or at least 15% by volume of the total volume of the coating, particularly the first portion 202. In a non-limiting embodiment, the total crystalline content of a coating, such as the first portion 202, can be limited due to the lack of high-temperature sintering. For example, in one non-limiting embodiment, a coating, such as first portion 202, can have a total crystalline content of 99% or less by volume of the total volume of the coating or first portion 202 of the coating, e.g., 97% or less, or 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less, or 10% or less, or 8% or less, or 5% or less, or 3% or less, or 2% or less by volume of the total volume of the coating; particularly, first portion 202 of the coating can have a total crystalline content of 1% or less by volume of the total volume of the coating. Furthermore, coating 202 can include a crystalline content within a range including any of the minimum and maximum percentages described herein. In a particular embodiment, first portion 202 of the coating can be essentially free of crystalline phases.

[0064] In another particular embodiment, the coating, e.g., first portion 202 of the coating, may include a major content of amorphous phase relative to the total volume of the first portion, e.g., at least 55% by volume of amorphous phase relative to the total volume of first portion 202, e.g., at least 60% by volume, or at least 70% by volume, or at least 80% by volume, or at least 90% by volume, or at least 95% by volume of amorphous content relative to the total volume of first portion 202 of the abrasive particle coating. In one particular example, first portion 202 may consist essentially of amorphous phase material. For example, in one particular embodiment, first portion 202 may include a mixture of amorphous phase silicon dioxide and amorphous phase silicate.

[0065] The degree of crystallinity can be determined by performing X-ray diffraction (also referred to in this disclosure as "XRD") analysis on a powder sample of the coating 202 prepared as follows: The first material can be placed in an alumina crucible and heated in a furnace at the sintering temperature described in the embodiments herein for 30 minutes. The crucible can then be removed from the furnace and allowed to cool at ambient temperature (i.e., 20°C to 25°C). The solid can be recovered from the crucible and manually ground, such as with a mortar and pestle, to obtain a powder sample of the coating 202. XRD can be obtained in Bragg-Brentano geometry (standard for powder XRD) using a copper X-ray source with a Cu K-alpha wavelength of 1.54 Å. Identification of the crystalline phase can be performed using EVA Bruker AXS software or another equivalent software and the ICDD-PDF4+ database (Release 2020). The crystallinity can be determined by Rietveld refinement using TOPAS 4.2 software from Bruker or another equivalent software according to the Corindon Al2O3 standard.

[0066] In some embodiments, the first portion of the coating can include domains having a particular average domain size that can facilitate improved abrasive particle formation and performance.

[0067] In another embodiment, the coating may include nanoparticles, a binder material, or a combination thereof. In a particular embodiment, the coating may include agglomerated particles including nanoparticles bound via a binder material. In some aspects, the binder material may include silicon and oxygen. In particular aspects, the binder material may include a silicate, such as a silicate including one or more alkali metals. In particular examples, the binder material may include a silicate including lithium and, optionally, another alkali metal, such as sodium, potassium, or any combination thereof. In even more particular examples, the binder material may consist essentially of lithium silicate. In another aspect, the nanoparticles may include silicon and oxygen. In particular aspects, the nanoparticles may include silica.

[0068] In another embodiment, the coating may include nanopores, such as pores having a pore size of 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less, 10 nm or less, 8 nm or less, or 6 nm or less. Additionally or alternatively, the coating may include pores having a pore size of at least 1 nm, at least 5 nm, at least 7 nm, at least 10 nm, at least 20 nm, at least 30 nm, at least 40 nm, at least 50 nm, at least 60 nm, at least 70 nm, at least 80 nm, at least 90 nm, at least 100 nm, at least 200 nm, or at least 30 nm. Furthermore, the coating may include pores having a size within a range including any of the minimum and maximum values ​​described herein.

[0069] In another embodiment, the coating may contain porosity at a specific content, such as at least 0.0001% by volume relative to the total volume of the abrasive particle, or at least 0.0005%, at least 0.001%, at least 0.005%, at least 0.01%, at least 0.05%, at least 0.1%, at least 0.5%, or at least 1% by volume relative to the total volume of the abrasive particle. Additionally or alternatively, the coating may contain porosity of 10% by weight or less relative to the total weight of the abrasive particle, or 9% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.5% by weight or less, 0.1% by weight or less, 0.05% by weight or less, 0.01% by weight or less, or 0.005% by weight or less relative to the total weight of the abrasive particle. Furthermore, the coating may contain a porosity content within a range including any of the minimum and maximum percentages described herein.

[0070] In another embodiment, the coating may comprise a density of at least 51% of theoretical density, such as at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, or at least 85%, or at least 90% of theoretical density. Additionally or alternatively, the coating may comprise a density of 98% or less of theoretical density, such as 95% or less, 93% or less, 90% or less, or 88% or less of theoretical density. Further, the coating may comprise a density range including any of the minimum and maximum percentages described herein. In further embodiments, the core may comprise a higher density than the coating.

[0071] In some embodiments, the coating may include a particular roughness that may facilitate improving the properties and / or performance of the abrasive particles.

[0072] In another embodiment, the coating can include a specific core coverage, which can facilitate improved properties and / or performance of the abrasive particle. In one example, the coating coverage can be at least 75% of the core's surface area, e.g., at least 80%, at least 85%, at least 90%, or at least 93% of the core's surface area. In another example, the coating coverage can be 99% or less of the core's surface area, e.g., greater than 97%, 95% or less, 93% or less, 90% or less, or 88% or less of the core's surface area. Furthermore, the coating coverage can be a range that includes any of the minimum and maximum percentages described herein.

[0073] In some embodiments, the coating may include a certain average number of discrete nanoparticles (loose nanoparticles) per certain area, which may facilitate improving the properties and / or performance of the abrasive particle.

[0074] 3 includes an atomic force microscopic (also referred to in this disclosure as "AFM") phase image of an abrasive particle. FIG. 3 includes an image of core 301, which includes crystallites 310.

[0075] In some embodiments, the abrasive particles can have an average domain size of at least 50 nm, at least 55 nm, at least 60 nm, at least 65 nm, at least 70 nm, at least 75 nm, at least 80 nm, at least 90 nm, at least 100 nm, at least 200 nm, at least 300 nm, at least 400 nm, at least 500 nm, or at least 600 nm. In other aspects, the abrasive particles can have an average domain size of greater than 26 nm or greater. In certain aspects, the abrasive particles can have an average domain size of 3 mm or less, 2 mm or less, 1 mm or less, 0.5 mm or less, 0.1 mm or less, 0.01 mm or less, or 0.001 mm or less. Furthermore, the abrasive particles can have an average domain size that includes any of the minimum and maximum values ​​described herein. As used herein, average domain size is intended to refer to the average of the largest dimensions of at least 20 distinguishable domains in a phase image of a randomly selected abrasive particle. The domain size of the abrasive particles was measured by scanning electron microscopy (SEM) of the polished section of the abrasive particle. A magnification of 50,000x was used, and the specimens were thermally etched at 100°C for 5 minutes. The domain size was obtained by intercept method without statistical correction.

[0076] In some embodiments, the abrasive particles may include a particular domain size standard deviation, which may facilitate improved abrasive particle formation and performance. In some aspects, the domain size standard deviation is 50% or less of the average domain size, 49% or less, 48% or less, 47% or less, 46% or less, 45% or less, 44% or less, 43% or less, 42% or less, 41% or less, 40% or less, 39% or less, 38% or less, 37% or less, 36% or less, 35% or less, 33% or less, 31% or less, 30% or less, 29% or less, 27% or less, 25% or less, 23% or less, 21% or less, 20% or less, 19% or less of the average domain size of the coating. % or less, 17% or less, 16% or less, 15% or less, 49% or less, 48% or less, 47% or less, 46% or less, 45% or less, 43% or less, 42% or less, 41% or less, 40% or less, 39% or less, 37% or less, 35% or less, 33% or less, 30% or less, 28% or less, 26% or less, 24% or less, 21% or less, 19% or less, 17% or less, 15% or less, 13% or less, 11% or less, 10% or less, 9% or less, 8% or less, 7% or less, or 5% or less. In another embodiment, the abrasive particles can comprise a domain size standard deviation having an absolute value of at least 0.001%, at least 0.01%, at least 0.1%, at least 1%, at least 2%, at least 4%, at least 3%, or at least 5% of the domain size of the coating. Additionally, the abrasive particles can include a standard deviation having an absolute value within a range that includes any of the minimum and maximum values ​​described herein.

[0077] In another embodiment, the abrasive particles can comprise a standard deviation having an absolute value of 65 nm or less, 63 nm or less, 61 nm or less, 60 nm or less, 58 nm or less, 55 nm or less, 53 nm or less, 51 nm or less, 50 nm or less, 49 nm or less, 47 nm or less, 45 nm or less, 43 nm or less, 41 nm or less, 40 nm or less, 38 nm or less, 36 nm or less, 32 nm or less, 30 nm or less, 28 nm or less, 25 nm or less, 23 nm or less, 22 nm or less, 20 nm or less, 19 nm or less, 17 nm or less, 16 nm or less, 15 nm or less, 14 nm or less, 13 nm or less, or 12 nm or less. In another embodiment, the abrasive particles can include a domain size standard deviation having an absolute value of at least 0.1 nm, at least 0.3 nm, at least 0.5 nm, at least 1 nm, at least 2 nm, at least 3 nm, at least 4 nm, at least 5 nm, at least 6 nm, at least 7 nm, at least 8 nm, at least 9 nm, at least 10 nm, at least 11 nm, at least 12 nm, at least 13 nm, at least 14 nm, at least 15 nm, at least 16 nm, or at least 17 nm. Further, the standard deviation can have an absolute value within a range that includes any of the minimum and maximum values ​​described herein.

[0078] In further embodiments, the abrasive particles (i.e., 200 or 210 illustrated in Figures 2A and 2B, respectively) may comprise a particular specific surface area that may facilitate improved properties and performance of the abrasive article. For example, the abrasive particles may comprise a specific surface area of ​​0.05 m 2 / g, e.g., at least 0.10 m 2 / g, at least 0.15m 2 / g, at least 0.17m 2 / g, at least 0.19m 2 / g, at least 0.21m 2 / g, at least 0.23m 2 / g, at least 0.25m 2 / g, at least 0.26m 2 / g, at least 0.28m 2 / g, at least 0.29m 2 / g, at least 0.31m 2 / g, at least 0.32m2 / g, at least 0.33m 2 / g, at least 0.35m 2 / g, at least 0.37m 2 / g, at least 0.38m 2 / g, at least 0.39m 2 / g, at least 0.4m 2 / g, at least 0.42m 2 / g, at least 0.44m 2 / g, at least 0.45m 2 / g, at least 0.46m 2 / g, at least 0.48m 2 / g, at least 0.5m 2 / g, at least 0.52m 2 / g, at least 0.54m 2 / g, at least 0.55m 2 / g, at least 0.56m 2 / g, at least 0.58m 2 / g, at least 0.59m 2 / g, at least 0.61m 2 / g, at least 0.63m 2 / g, at least 0.64m 2 / g, or at least 0.66m 2 In another example, the abrasive particles may comprise a specific surface area of ​​2.2 m 2 / g or less, e.g., 1.8m 2 / g or less, 1.6m 2 / g or less, 1.3m 2 / g or less, 1.2m 2 / g or less, 1.1m 2 / g or less, 0.96m 2 / g or less, 0.94m 2 / g or less, 0.91m 2 / g or less, 0.88m 2 / g or less, 0.86m 2 / g or less, 0.83m 2 / g or less, 0.8m 2 / g or less, 0.76m 2 / g or less, 0.73m 2 / g or less, 0.71m 2 / g or less, 0.68m 2 / g or less, 0.66m2 / g or less, 0.63m 2 / g or less, 0.6m 2 / g or less, 0.58m 2 / g or less, 0.55m 2 / g or less, 0.54m 2 / g or less, 0.52m 2 / g or less, 0.5m 2 / g or less, 0.47m 2 / g or less, 0.45m 2 / g or less, 0.42m 2 / g or less, 0.4m 2 / g or less, 0.38m 2 / g or less, 0.37m 2 / g or less, 0.36m 2 / g or less, 0.34m 2 / g or less, 0.31m 2 / g or less, 0.3m 2 / g or less, 0.28m 2 / g or less, 0.27m 2 / g or less, 0.25m 2 / g or less, 0.23m 2 / g or less, 0.21m 2 / g or less, or 0.18m 2 / g or less. Additionally, the abrasive particles may have a specific surface area within a range including any of the minimum and maximum values ​​described herein. For example, the abrasive particles may have a specific surface area of ​​at least 0.15 m 2 / g and 1.8m 2 / g or less, or at least 0.18m 2 / g and 1.2m 2 / g or less, or at least 0.23m 2 / g and 0.45m 2 / g or less. As used herein, specific surface area may be determined using Brunauer-Emmett-Teller (BET) surface area analysis according to ISO 9277-2010 using nitrogen gas at a bath temperature of 77.35 K.

[0079] In further embodiments, abrasive particles having a particular average particle size (i.e., 200 or 210 illustrated in Figures 2A and 2B, respectively) may have an improved specific surface area compared to a corresponding conventional abrasive particle. As used herein, a corresponding conventional abrasive particle may have the same average particle size and material, but may have a conventional coating.

[0080] In some embodiments, abrasive particles having an average particle size of 600-650 microns may have a particular specific surface area that may facilitate improved performance of the abrasive particles. In some examples, abrasive particles 200 or 210 having an average particle size of 600-650 microns may have a specific surface area of ​​at least 0.08 m 2 / g, at least 0.10m 2 / g, at least 0.12m 2 / g, at least 0.13m 2 / g, at least 0.14m 2 / g, at least 0.15m 2 / g, at least 0.16m 2 / g, at least 0.17m 2 / g, or at least 0.18m 2 / g, etc. 2 In another example, abrasive particles 200 or 210 having an average particle size of 600 to 650 microns may have a specific surface area of ​​0.50 m 2 / g or less, e.g., 0.48m 2 / g or less 、 0.46m 2 / g or less, 0.43m 2 / g or less, 0.40m 2 / g or less, 0.38m 2 / g or less, 0.36m 2 / g or less, 0.34m 2 / g or less, 0.31m 2 / g or less, 0.28m 2 / g or less, 0.26m 2 / g or less, 0.23m 2 / g or less, 0.21m 2 / g or less, or 0.18m 2 / g or less. Furthermore, abrasive particles 200 or 210 having an average particle size of 600-650 microns may have a specific surface area ranging from any of the minimum and maximum values ​​described herein. For example, abrasive particles 200 or 210 having an average particle size of 600-650 microns may have a specific surface area ranging from 0.05 m 2 / g and 0.50m 2 / g or at least 0.08m 2 / g~0.40m 2 / g or less, or at least 0.10m 2 / g~0.34m 2 / g or less, or at least 0.12m 2 / g~0.23m 2 / g or less.

[0081] In another embodiment, the abrasive particles 200 or 210 having an average particle size of 220-300 microns may have a particular specific surface area that may facilitate improved performance of the abrasive particles. In one example, the abrasive particles 200 or 210 having an average particle size of 220-300 microns may have a specific surface area of ​​0.15 m 2 / g, e.g., at least 0.16 m / g 2 / g, at least 0.17m 2 / g, at least 0.18m 2 / g, at least 0.19m 2 / g, at least 0.21m 2 / g, at least 0.23m 2 / g, at least 0.25m 2 / g, at least 0.26m 2 / g, at least 0.28m 2 / g, at least 0.29m 2 / g, at least 0.31m 2 / g, at least 0.32m 2 / g, at least 0.33m 2 / g, at least 0.35m 2 / g, at least 0.37m 2 / g, at least 0.38m 2 / g, at least 0.39m 2 / g, at least 0.4m2 / g, at least 0.42m 2 / g, at least 0.44m 2 / g, or at least 0.45m 2 In another example, abrasive particles 200 or 210 having an average particle size of 220 to 300 microns may have a specific surface area of ​​1.10 m 2 / g or less, e.g., 0.96m 2 / g or less, 0.94m 2 / g or less, 0.91m 2 / g or less, 0.88m 2 / g or less, 0.86m 2 / g or less, 0.83m 2 / g or less, 0.8m 2 / g or less, 0.76m 2 / g or less, 0.73m 2 / g or less, 0.71m 2 / g or less, 0.68m 2 / g or less, 0.66m 2 / g or less, 0.63m 2 / g or less, 0.6m 2 / g or less, 0.58m 2 / g or less, 0.55m 2 / g or less, 0.54m 2 / g or less, 0.52m 2 / g or less, 0.5m 2 / g or less, 0.47m 2 / g or less, or 0.45m 2 / g or less. Furthermore, abrasive particles 200 or 210 having an average particle size of 220-300 microns may have a specific surface area ranging from any of the minimum and maximum values ​​described herein. For example, abrasive particles having an average particle size of 220-300 microns may have a specific surface area of ​​0.15 m 2 / g and 1.10m 2 / g or at least at least 0.28m 2 / g and 0.66m 2 / g or less, or at least 0.35m 2 / g and 0.52m 2 / g or less.

[0082] In yet another embodiment, the abrasive particles 200 or 210 having an average particle size of 80 to 110 microns may have a particular specific surface area that may facilitate improved performance of the abrasive particles. In one example, the abrasive particles 200 or 210 having an average particle size of 80 to 110 microns may have a specific surface area of ​​0.22 m 2 / g, e.g., at least 0.23 m 2 / g, at least 0.25m 2 / g, at least 0.26m 2 / g, at least 0.28m 2 / g, at least 0.29m 2 / g, at least 0.31m 2 / g, at least 0.32m 2 / g, at least 0.33m 2 / g, at least 0.35m 2 / g, at least 0.37m 2 / g, at least 0.38m 2 / g, at least 0.39m 2 / g, at least 0.4m 2 / g, at least 0.42m 2 / g, at least 0.44m 2 / g, at least 0.45m 2 / g, at least 0.46m 2 / g, at least 0.48m 2 / g, at least 0.5m 2 / g, at least 0.52m 2 / g, at least 0.54m 2 / g, at least 0.55m 2 / g, at least 0.56m 2 / g, at least 0.58m 2 / g, at least 0.59m 2 / g, at least 0.61m 2 / g, at least 0.63m 2 / g, at least 0.64m 2 / g, or at least 0.66m 2 In another example, abrasive particles 200 or 210 having an average particle size of 80 to 110 microns may have a specific surface area of ​​2.2 m 2 / g or less, e.g., 1.8m2 / g or less, 1.6m 2 / g or less, 1.3m 2 / g or less, 1.2m 2 / g or less, 1.1m 2 / g or less, 0.96m 2 / g or less, 0.94m 2 / g or less, 0.91m 2 / g or less, 0.88m 2 / g or less, 0.86m 2 / g or less, 0.83m 2 / g or less, 0.8m 2 / g or less, 0.76m 2 / g or less, 0.73m 2 / g or less, 0.71m 2 / g or less, 0.68m 2 / g or less, or 0.66m 2 / g or less. Furthermore, abrasive particles 200 or 210 having an average particle size of 80 to 110 microns may have a specific surface area that includes any of the minimum and maximum values ​​described herein. For example, abrasive particles having an average particle size of 80 to 110 microns may have a specific surface area of ​​0.22 m 2 / g and 2.2m 2 / g or less, or 0.38m 2 / g~0.94m 2 / g range, or 0.58m 2 / g~0.72m 2 In yet another embodiment, the abrasive particles having an average particle size in the range of 80 to 650 microns may have a specific surface area in the range of 0.15 m 2 / g~0.72m 2 / g range or 0.18m 2 / g~0.66m 2 The specific surface area may be in the range of / g.

[0083] Referring to FIG. 1 , the process can proceed to block 104, where a second portion of the coating can be formed over at least a portion of the core. Forming the second portion can include treating the core with the second coating. In some embodiments, the second coating can include a coupling agent, e.g., a silicon-containing compound such as a silane or another organosilicon compound. In particular, the second coating can include an organosilicon coupling agent that can provide improved bonding between a surface having —OH functional groups and an organic polymer material. For example, the second coating can include an organosilane having amino, alkoxy, alkylalkoxy, alkyltrialkoxy, vinyl, acrylo, methacrylo, mercapto, or other functional groups, or any combination thereof. Specific examples of silanes can include aminosilanes, including, for example, bis-aminosilane, aminoalkyltrialkoxysilane, aminoethyltriethoxysilane, aminopropyltriethoxysilane, phenylaminoalkyltrialkoxysilane, or any combination thereof. Further examples of organosilicon compounds can include siloxanes, silicone fluids, silsesquioxanes, etc., or any combination thereof.

[0084] In an exemplary embodiment, the core can be wetted with a solution containing a silane in a solvent such as water or ethanol. The concentration of the silane can range, for example, from 2% to 6% by volume. In other embodiments, the core can be coated with a second coating using in-situ spraying or other methods known in the art.

[0085] Forming the second portion of the coating can further include drying the wetted or otherwise coated core, which may be done at a temperature of 20°C to 180°C for 10 minutes to up to 36 hours for the second portion of the coating.

[0086] According to one embodiment, after applying the second portion 203, the finally formed abrasive particles may contain a particular content of silane-containing compound, including, for example, but not limited to, at least 0.02 wt.% of silane-containing compound based on the total weight of the coating. In another embodiment, the coating may contain at least 0.5 wt.%, e.g., at least 1 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 4 wt.%, or at least 5 wt.%, or at least 6 wt.%, or at least 7 wt.%, or at least 8 wt.%, or at least 9 wt.%, or at least 10 wt.% of silane-containing compound based on the total weight of the coating. In yet another non-limiting embodiment, the coating may contain 25 wt.% or less of silane-containing compound based on the total weight of the coating, e.g., 20 wt.% or less, or 18 wt.% or less, or 16 wt.% or less, or 14 wt.% or less, or 12 wt.% or less, or 10 wt.% or less of silane-containing compound based on the total weight of the coating. It will be understood that the coating may contain a content of silane-containing compound within a range, including any of the minimum and maximum values ​​stated above.

[0087] 2B, a cross section of an abrasive particle 210 is provided, depicting an abrasive particle according to an alternative embodiment. In one embodiment, the abrasive particle 210 can include a core 201 and a coating 205 covering the core 201. The coating 205 can include a first portion 202 covering the core 201 and an optional second portion 203 covering the first portion 202 and the core 201. The first portion 202 can be disposed between the surface of the core 201 and the second portion 203. In one non-limiting embodiment, the abrasive particle 210 can be formed by first forming the abrasive particle as provided in FIG. 2A by using steps 101, 102, and 103, and then forming the optional second portion 203 covering the first portion of the core as provided in step 104.

[0088] In one non-limiting embodiment, second portion 203 can be in direct contact with first portion 202. In certain embodiments, second portion 203 can cover the entire surface of core 201, the entire first portion 202, or both. In one embodiment, second portion 203 can cover a majority of first portion 202. For example, a portion of first portion 202 may not be covered by second portion 203. In one embodiment, a portion of the core surface can be in direct contact with second portion 203. In further embodiments, second portion 203 can be bound to first portion 202 and to core 201.

[0089] In some embodiments, the second portion 203 of the coating 205 can include a silane or a silane reaction product. A silane reaction product is intended to refer to a silane derivative that can be formed in the process of forming the coating. For example, one suitable silane or silane reaction product can include 3-aminopropyltriethoxysilane.

[0090] In some embodiments, the abrasive particles 210 or 201 can include an average coating 205 or 202 content of at least 0.01% by weight relative to the weight of the core 201, for example, at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, at least 0.09%, at least 0.1%, at least 0.15%, at least 0.16%, at least 0.17%, at least 0.18%, at least 0.19%, at least 0.2%, at least 0.25%, at least 0.26%, at least 0.27%, at least 0.28%, at least 0.29%, or at least 0.3% by weight relative to the weight of the core 201. As used herein, the average coating 205 or 202 content can be the average of the coating content of at least five abrasive particles 210 or 201. In another example, the abrasive particles 210 or 201 can have an average coating 205 or 202 content of 1% or less by weight relative to the weight of the core 201, 0.9% or less by weight, 0.8% or less by weight, 0.7% or less by weight, 0.6% or less by weight, 0.55% or less by weight, 0.5% or less by weight, 0.48% or less by weight, 0.46% or less by weight, 0.45% or less by weight, 0.43% or less by weight, 0.42% or less by weight, 0.41% or less by weight, 0.4% or less by weight, 0.38% or less by weight, 0.37% or less by weight, 0.36% or less by weight, 0.35% or less by weight, or 0.34% or less by weight relative to the weight of the core 201. Additionally, the abrasive particles 210 can include an average coating 205 content ranging from any of the minimum and maximum percentages described herein.

[0091] In some embodiments, the abrasive particle 210 can include a particular average thickness of the coating 205 that can facilitate improved formation and properties of the abrasive particle 210. For example, the abrasive particle 210 can include an average thickness of the coating 205 that is 10 microns or less, 9 microns or less, 8 microns or less, 7 microns or less, 6 microns or less, 5 microns or less, 4 microns or less, 3 microns or less, 2 microns or less, 1 micron or less, 0.9 microns or less, 0.8 microns or less, 0.7 microns or less, 0.6 microns or less, 0.5 microns or less, or 0.4 microns or less, 0.3 microns or less, or 0.2 microns or less. In another example, the abrasive particles 210 can include an average coating 205 thickness of at least 0.05 microns, at least 0.06 microns, at least 0.07 microns, at least 0.08 microns, at least 0.09 microns, at least 0.1 microns, at least 0.11 microns, at least 0.12 microns, at least 0.13 microns, at least 0.14 microns, at least 0.15 microns, at least 0.16 microns, at least 0.17 microns, at least 0.18 microns, at least 0.19 microns, at least 0.20 microns, at least 0.21 microns, at least 0.22 microns, at least 0.24 microns, at least 0.26 microns, at least 0.28 microns, at least 0.29 microns, at least 0.30 microns, or at least 0.31 microns. Additionally, the abrasive particles 210 can include an average coating 205 thickness in a range including any of the minimum and maximum percentages described herein. As used herein, the average thickness of the coating 205 may refer to the average thickness of the coating 205 of at least five abrasive particles 210 .

[0092] In some embodiments, the abrasive particle 210 or 201 can include a particular ratio of the average thickness of the coating 205 or 202 to the average particle size of the core 201, respectively, which can facilitate improved formation and properties of the abrasive particle 210. For example, the ratio can be less than 1, e.g., 0.9 or less, 0.7 or less, 0.5 or less, 0.4 or less, 0.2 or less, 0.1 or less, 0.08 or less, 0.06 or less, 0.05 or less, 0.03 or less, 0.02 or less, 0.01 or less, 0.009 or less, 0.008 or less, 0.007 or less, 0.006 or less, 0.005 or less, 0.004 or less, 0.003 or less, 0.002 or less, or 0.1 or less. In another example, the ratio of the average thickness of the coating 205 or 202 to the average grain size of the core 201 can be at least 0.0005, at least 0.0007, at least 0.0009, at least 0.001, at least 0.002, at least 0.003, at least 0.004, at least 0.005, at least 0.006, at least 0.007, at least 0.008, at least 0.009, at least 0.01, at least 0.02, or at least 0.03. Furthermore, the ratio of the average thickness of the coating 205 or 202 to the average grain size of the core 201 can be a range including any of the minimum and maximum percentages described herein. As used herein, the average grain size of the core 201 refers to the D of the core 201. 50 is intended to refer to.

[0093] In some embodiments, the abrasive particles 210 and 201 have an average particle size (i.e., D) of at least 10 microns, at least 30 microns, at least 40 microns, at least 50 microns, at least 60 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 120 microns, at least 140 microns, at least 150 microns, at least 170 microns, at least 180 microns, at least 200 microns, at least 210 microns, at least 230 microns, at least 250 microns, at least 260 microns, at least 270 microns, at least 290 microns, at least 300 microns, at least 320 microns, at least 340 microns, at least 350 microns, at least 360 microns, at least 380 microns, at least 400 microns, at least 420 microns, at least 430 microns, at least 440 microns, at least 450 microns, at least 460 microns, at least 470 microns, at least 490 microns, or at least 500 microns. 50 ). In another embodiment, the abrasive particles 210 and 201 can comprise an average particle size of 3 mm or less, e.g., 2 mm or less, 1.8 mm or less, 1.6 mm or less, 1.5 mm or less, 1.2 mm or less, 1 mm or less, 900 microns or less, 850 microns or less, 830 microns or less, 800 microns or less, 750 microns or less, 700 microns or less, 650 microns or less, 600 microns or less, 550 microns or less, 500 microns or less, 450 microns or less, or 400 microns or less. Furthermore, the abrasive particles 210 and 201 can comprise an average particle size within a range including any of the minimum and maximum values ​​described herein.

[0094] It should be noted that the abrasive particles of embodiments herein may have improved characteristics, properties, and / or performance compared to corresponding conventional abrasive particles. As used herein, the term "conventional abrasive particle" is intended to refer to an abrasive particle having the same core and coating as the abrasive particles of embodiments herein, except that the coating of the conventional abrasive particle is formed using a different process than the abrasive particles of embodiments herein. Such improved characteristics of the abrasive particle may include morphology, coating coverage, average coating thickness, coating thickness uniformity, such as standard deviation of coating thickness, average domain size of the coating, standard deviation of domain size of the coating, or any combination thereof. In particular, the abrasive particles of embodiments herein have statistically relevant sample sizes, and the improved characteristics, properties, and performance are described for all samples of the abrasive particle. For example, the abrasive particles can be at least 1 kg of abrasive particles, at least 2 kg of abrasive particles, at least 4 kg of abrasive particles, at least 5 kg of abrasive particles, at least 7 kg of abrasive particles, at least 8 kg of abrasive particles, at least 10 kg of abrasive particles, at least 20 kg of abrasive particles, at least 30 kg of abrasive particles, at least 50 kg of abrasive particles, at least 100 kg of abrasive particles, at least 250 kg, at least 500 kg, or at least 1 ton of abrasive particles. In another example, the abrasive particles can constitute a significant proportion of the abrasive particles from the fixed abrasive article. In yet another example, at least 100 abrasive particles, at least 500 abrasive particles, at least 1000 abrasive particles, at least 2000 abrasive particles, at least 5000 abrasive particles, at least 8000 abrasive particles, at least 10,000 abrasive particles, or at least 500,000 abrasive particles.

[0095] It should also be noted that the process variables and parameters of embodiments herein may be controlled and / or adapted to facilitate the formation of abrasive particles with improved coating properties, as well as improved characteristics, properties, and performance. The processes of embodiments herein may facilitate the formation of abrasive particles with improved quality compared to corresponding conventional abrasive particles. For example, the drying conditions, silica concentration, mixing conditions, and / or other process features described in embodiments herein may help reduce the formation of abrasive particle agglomerates and prevent degradation of the core material and the formation of an improved coating. The abrasive particles may include a coating that may be conformal and uniform.

[0096] In further embodiments, the abrasive particle 201 or 210 can comprise an anti-aging factor that is at least 5% better than a plurality of corresponding conventional abrasive particles, at least 8% better than a plurality of corresponding conventional abrasive particles, at least 10% better, at least 12% better, at least 15% better, at least 18% better, at least 20% better, at least 22% better, at least 24% better, at least 25% better, at least 28% better, at least 30% better, at least 32% better, at least 35% better, at least 36% better, at least 38% better, or at least 40% better.

[0097] In some embodiments, coating 202 or 205 can have a particular hardness that can facilitate improved performance and / or properties of the abrasive particles and abrasive articles. In some aspects, the hardness can be greater than 1 GPa, e.g., at least 1.5 GPa, at least 1.8 GPa, at least 2 GPa, at least 2.2 GPa, at least 2.5 GPa, at least 2.8 GPa, or at least 3 GPa. In other aspects, the hardness can be less than 10 GPa, e.g., less than 8 GPa, up to 7 GPa, up to 6 GPa, up to 5 GPa, up to 4 GPa, up to 3.8 GPa, up to 3.5 GPa, up to 3.3 GPa, up to 3.2 GPa, or up to 3 GPa. In further aspects, coating 202 or 205 can have a hardness range that includes any of the minimum and maximum values ​​described herein. Hardness can be determined as follows: The prepared suspension can be deposited on a flat alumina substrate (99.5% purity) by dip coating. The coated substrate can be dried as described in the embodiments herein. Nanoindentation can be performed on the coated plate. Twenty indentations can be made to determine the hardness of the coating.

[0098] 4 includes a cross-sectional view of a bonded abrasive article 400 including a body 401 including abrasive particles 210 contained within a bond material 403. In at least one embodiment, the bond material 403 defines an interconnected continuous phase throughout the entire volume of the body 401. In another embodiment, the bond material 403 can form a three-dimensional matrix. In another embodiment, the abrasive particles 201 can be used alone or in combination with the abrasive particles 210 in forming the abrasive article 400.

[0099] In some embodiments, the abrasive particles 210 can be bonded to the bond material 403. In further embodiments, a portion of the coating 203 can be crosslinked to the bond material 403. For example, a silane or silane derivative can be crosslinked to the bond material in the process of forming the body 401.

[0100] In some embodiments, the bonding material 403 can include an organic material, an inorganic material, a ceramic material, a glassy material, a metal, or a metal alloy material. In certain embodiments, the bonding material 403 can include an organic material, such as one or more natural organic materials, synthetic organic materials, or combinations thereof. In certain examples, the organic material can be made from a resin, which can include thermosets, thermoplastics, and combinations thereof. For example, some suitable resins can include phenolics, epoxies, polyesters, cyanate esters, shellacs, polyurethanes, polybenzoxazines, polybismaleimides, polyimides, rubbers, and combinations thereof.

[0101] The phenolic resin may be modified with a curing or crosslinking agent such as hexamethylenetetramine. At temperatures above about 90°C, some examples of hexamethylenetetramine may crosslink to form methylene and dimethylene amino crosslinks that aid in curing the resin. The hexamethylenetetramine may be uniformly dispersed throughout the resin. More specifically, the hexamethylenetetramine may be uniformly dispersed within the resin regions as a crosslinking agent. Even more specifically, the phenolic resin may contain resin regions with crosslinked domains having an average size of submicrons.

[0102] In some embodiments, the body 401 can include a particular content of bond material 403 that can facilitate improved formation of the abrasive article. In one example, the body 401 can include 98% by volume or less, or 95% by volume or less, or 90% by volume or less, or 85% by volume or less, or 80% by volume or less, or 75% by volume or less, or 70% by volume or less, or 65% by volume or less, or 60% by volume or less, or 55% by volume or less, or 50% by volume or less, or 45% by volume or less, or 40% by volume or less, or 35% by volume or less, or 30% by volume or less, or 25% by volume or less of the bond material 403, based on the total volume of the body. In another example, the body 401 can include at least 1% by volume, or at least 2% by volume, or at least 5% by volume, or at least 10% by volume, or at least 20% by volume, or at least 30% by volume, or at least 35% by volume, or at least 40% by volume, or at least 45% by volume of the bond material 403, based on the total volume of the body. Additionally, the body 401 may include a binder material 403 in a content including any of the minimum and maximum percentages described herein.

[0103] In some embodiments, the body 401 can include a certain content of abrasive particles 210 and / or 201, which can facilitate improved properties and performance of the abrasive article. In some examples, the body 401 can include 65% by volume or less of the abrasive particles 210 and / or 201, based on the total volume of the body 401, e.g., 64% by volume or less, or 62% by volume or less, or 60% by volume or less, or 58% by volume or less, or 56% by volume or less, or 54% by volume or less, or 52% by volume or less, or 50% by volume or less, or 48% by volume or less, or 46% by volume or less, or 44% by volume or less, or 42% by volume or less, or 40% by volume or less, or 38% by volume or less, or 36% by volume or less, or 34% by volume or less, or 32% by volume or less, or 30% by volume or less, or 28% by volume or less, or 26% by volume or less, or 24% by volume or less, or 22% by volume or less, or 20% by volume or less of the abrasive particles 210 and / or 201. In another example, the body 901 can include at least 1 volume % of the abrasive particles 210 and / or 201 relative to the total volume of the body 401, for example, at least 2 volume %, or at least 4 volume %, or at least 6 volume %, or at least 8 volume %, or at least 10 volume %, or at least 12 volume %, or at least 14 volume %, or at least 16 volume %, or at least 18 volume %, or at least 20 volume %, or at least 25 volume %, or at least 30 volume %, or at least 35 volume % of the abrasive particles 210 and / or 201 relative to the total volume of the body 401. Furthermore, the body 401 can include a content of the abrasive particles 210 and / or 201 within a range including any of the minimum and maximum percentages described herein.

[0104] In at least one embodiment, the body 401 can include abrasive particles including a core 201 having at least one different characteristic including composition, shape, hardness, particle size, friability, toughness, crystallite size, or any combination thereof. For example, the core 201 can include shaped abrasive particles and non-shaped particles or abrasive particles having different shapes. In a further example, the core 201 can include a first type of abrasive particles including premium abrasive particles (e.g., fused alumina, alumina-zirconia, seeded sol-gel alumina, shaped abrasive particles, etc.) and a second type of abrasive particles including diluted abrasive particles.

[0105] In some embodiments, the body 401 may include a specific content of uncoated abrasive grains in addition to the abrasive particles 210 and / or 201. In other embodiments, the body 401 may include a blend of abrasive particles, at least a portion of the blend including the abrasive particles 210 and / or 201. In some embodiments, the body 401 may include a specific content of the abrasive particles 210 and / or 201 relative to the total content of the abrasive particles in the body, which may facilitate improved performance of the abrasive article. In some examples, the body can include at least 10% abrasive particles 210 and / or 201 by volume of the total abrasive particle content, such as at least 13%, at least 15%, at least 17%, at least 19%, at least 21%, at least 24%, at least 26%, at least 30%, at least 34%, at least 36%, at least 40%, at least 45%, at least 48%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% abrasive particles 210 and / or 201 by volume of the total abrasive particle content. In certain examples, the abrasive particles 210 and / or 201 can constitute essentially all of the abrasive particles within the body 401. In further examples, the body may comprise 99% or less abrasive particles 210 and / or 201, based on the total volume content of abrasive particles, for example, 95% or less, 92% or less, 89% or less, 85% or less, 82% or less, 80% or less, 75% or less, 72% or less, 69% or less, 64% or less, 60% or less, 55% or less, 52% or less, 49% or less, 45% or less, 41% or less, 39% or less, 36% or less, 33% or less, or 30% or less, based on the total volume content of abrasive particles 210 and / or 201. Furthermore, the body may comprise a content of abrasive particles 210 and / or 201 within a range including any of the minimum and maximum percentages described herein.

[0106] 4, the body 401 further includes a central opening 430 and an axial axis 931 extending axially through the central opening 430, which may be perpendicular to a radial axis extending along a direction defining a diameter (d) of the body. It will be understood that any other fillers and / or body phases (e.g., porosity) may be contained within the bonding material 403.

[0107] In certain embodiments, the body 401 can include a type of porosity selected from the group consisting of closed porosity, open porosity, and combinations thereof. In certain aspects, the majority of the porosity can be closed porosity defined by discrete pores, and in certain aspects, the porosity can consist essentially of closed porosity. In other aspects, the majority of the porosity can be open porosity defining a network of interconnected channels extending through at least a portion of the body, and in certain aspects, essentially all of the porosity can be open porosity. In yet other aspects, the porosity can include a combination of open porosity and closed porosity.

[0108] In some embodiments, the body 401 can include a certain porosity that can facilitate improved properties and performance of the abrasive article. In some examples, the body 401 can include at least 1% by volume, or at least 2% by volume, or at least 4% by volume, or at least 6% by volume, or at least 8% by volume, or at least 10% by volume, or at least 12% by volume, or at least 14% by volume, or at least 16% by volume, or at least 18% by volume, or at least 20% by volume, or at least 25% by volume, or at least 30% by volume, or at least 40% by volume, or at least 45% by volume, or at least 50% by volume, or at least 55% by volume of porosity, based on the total volume of the body. In another example, the body 401 may comprise 80% by volume or less, or 75% by volume or less, or 70% by volume or less, or 65% by volume or less, or 60% by volume or less, or 55% by volume or less, or 50% by volume or less, or 45% by volume or less, or 40% by volume or less, or 35% by volume or less, or 30% by volume or less, or 25% by volume or less, or 20% by volume or less, or 15% by volume or less, or 10% by volume or less, or 5% by volume or less, or 2% by volume or less, based on the total volume of the body. Furthermore, the body 401 may comprise a porosity range including any of the minimum and maximum percentages described herein. The porosity of the body 401 was measured using mercury porosimetry (micromeritics AutoPore IV9520) to quantify the porosity in the body. A 1 cm x 1 cm x 1 cm sample was cut from the body and measured at low pressure (50 μm Hg) and high pressure (10 s equilibration time) to obtain the bulk and apparent density of the body. Porosity was then calculated by the formula: (Porosity = [100 - (bulk density / apparent density)].

[0109] In certain embodiments, the body 401 can include a filler. For example, the body 401 can include 40% or less by volume of filler, based on the total volume of the body. In certain examples, the body 401 can have 35% or less by volume of filler, e.g., 30% or less, or 25% or less, or 20% or less, or 15% or less, or 10% or less, or 8% or less, or 5% or less, or 4% or less, or even 3% or less by volume. For at least one embodiment, the body 401 can be free of filler. According to one non-limiting embodiment, the body 401 can have at least 0.05% by volume of filler, based on the total volume of the body 401, e.g., at least 0.5% by volume, or at least 1% by volume, or at least 2% by volume, or at least 3% by volume, or at least 5% by volume, or at least 10% by volume, or at least 15% by volume, or at least 20% by volume, or even at least 30% by volume of filler. Additionally, the filler within body 401 may be within a range between any of the minimum and maximum percentages noted above, including, but not limited to, a content within a range of at least 0.5% by volume and not more than 30% by volume.

[0110] The filler may comprise a material selected from the group consisting of powders, granules, spheres, fibers, and combinations thereof. Additionally, in certain examples, the filler may comprise inorganic materials, organic materials, fibers, woven materials, nonwoven materials, particles, minerals, nuts, shells, oxides, aluminas, carbides, nitrides, borides, polymeric materials, natural materials, and combinations thereof. In certain embodiments, the filler is selected from the group consisting of sand, bubble alumina, chromite, magnesite, dolomite, bubble mullite, borides, titanium dioxide, carbon products (e.g., carbon black, coke, or graphite), silicon carbide, wood flour, clay, talc, hexagonal boron nitride, molybdenum disulfide, feldspar, nepheline syenite, glass spheres, glass fiber, CaF2, KBF4, cryolite (Na3AlF6), potassium cryolite (K3AlF6), pyrite, ZnS, copper sulfide, mineral oil, fluoride, carbonate, calcium carbonate, wollastonite, mullite, steel, iron, copper, brass, bronze, tin, aluminum, kyanite, alucite, garnet, The materials may include quartz, fluoride, mica, nepheline syenite, sulfates (e.g., barium sulfate), carbonates (e.g., calcium carbonate), titanates (e.g., potassium titanate fiber), rock wool, clay, sepiolite, iron sulfides (e.g., FeS, FeS, or combinations thereof), potassium borofluoride (KBF), zinc borate, borax, boric acid, fine alundum flour, P15A, coke, glass spheres, silica microspheres (Z-lite), silver, Saran™ resin, paradichlorobenzene, oxalic acid, alkali halides, organic halides, attapulgite, or any combination thereof.

[0111] In at least one embodiment, the filler may comprise a material selected from the group consisting of an antistatic agent, a lubricant, a porosity inducer, a colorant, and combinations thereof. In certain instances where the filler is a particulate material, the filler may be different from the abrasive particles and have an average particle size significantly smaller than the abrasive particles.

[0112] The body 401 is illustrated in cross section as having a generally rectangular shape, which may be annular, representing a wheel or disc shape having a central opening 430. It will be understood that the abrasive articles of embodiments herein can have bodies that may be in the form of horns, cones, cups, flange shapes, cylinders, wheels, rings, and combinations thereof.

[0113] The body 401 can have a generally circular shape when viewed from above. It will be understood that in three dimensions, the body 401 can have a certain thickness (t) such that the body 401 has a disk-like or cylindrical shape. As shown, the body 401 can have an outer diameter (d) extending through the center of the body 401. A central opening 430 can extend through the entire thickness (t) of the body 401 so that the abrasive article 400 can be attached to a spindle or other machine for rotating the abrasive article 400 during operation. According to one embodiment, the body 401 can have a certain relationship between the thickness (t) and the diameter (d), such that the aspect ratio (d:t) of the body is at least 10:1, e.g., at least 20:1, or at least 30:1, or at least 40:1, or at least 50:1, or at least 60:1, or at least 70:1, or at least 80:1, or at least 90:1, or at least 100:1. Still, in one non-limiting embodiment, the aspect ratio (d:t) may be equal to or less than 1000:1, or equal to or less than 500:1. It will be understood that the aspect ratio (d:t) may be within a range between any of the minimum and maximum values ​​stated above.

[0114] In some aspects, the bonded abrasive article 400 according to some embodiments can have a wet retention value, where the wet retention value is measured by dividing the wet MOR value of the bonded abrasive article by the dry MOR value of the bonded abrasive article and multiplying by 100. In certain embodiments, the bonded abrasive article can have a wet retention value of at least 70%, e.g., at least 71%, or at least 72%, or at least 73%, or at least 74%, or at least 75%, or at least 76%, or at least 77%, or at least 78%, or at least 79%, or at least 80%, or at least 81%, or at least 82%, or at least 83%, or at least 84%, or even at least 85%. Still, in one non-limiting embodiment, the wet retention value can be 99.9% or less, or 99.5% or less, or 99% or less, or 98% or less, or 96% or less, or 94% or less, or 92% or less, or 90% or less. It will be understood that the wet retention value can be within a range including any of the minimum and maximum values ​​mentioned above. The MOR of the abrasive article 400 was measured by a three-point bending test performed on an Instron® universal testing machine using the following parameters: test speed was 1.27 mm / min, support span was 50.8 mm, and load cell was 10 kN. The three-point bending test was performed on a bar sample representing the abrasive article 400 having dimensions of 4.0 x 1.0 x 0.5 inches. At least three samples were tested to obtain the maximum bending stress (i.e., the modulus of rupture (MOR)) of the abrasive article.

[0115] 5 includes an illustrative diagram of a process for forming an abrasive article including a body. At block 601, the process can include forming a mixture including a bond material and / or a bond precursor material and abrasive particles.

[0116] According to one embodiment, the bond material and / or bond precursor material may comprise a material selected from the group consisting of an organic material, an organic precursor material, an inorganic material, an inorganic precursor material, a naturally occurring material, and combinations thereof. In certain examples, the bond material may comprise a metal or metal alloy, such as a powder metal material, or a precursor of a metallic material suitable for forming a metallic bond matrix material during further processing.

[0117] According to another embodiment, the mixture can include a vitreous material or a precursor of a vitreous material suitable for forming a vitreous bonding material during further processing. For example, the mixture can include a vitreous material in powder form, including, for example, an oxygen-containing material, an oxide compound or complex, a frit, and any combination thereof.

[0118] In yet another embodiment, the mixture can include ceramic materials or precursors of ceramic materials suitable for forming a ceramic bond material during further processing. For example, the mixture can include ceramic materials in powder form, including, for example, oxygen-containing materials, oxide compounds or complexes, and any combination thereof.

[0119] According to another embodiment, the mixture may include an organic material or a precursor of an organic material suitable for forming an organic bond material during further processing. Such organic materials may include one or more natural organic materials, synthetic organic materials, and combinations thereof. In certain examples, the organic material may be made from a resin, which may include thermosets, thermoplastics, and combinations thereof. For example, some suitable resins may include phenolics, epoxies, polyesters, cyanate esters, shellacs, polyurethanes, polybenzoxazines, polybismaleimides, polyimides, rubbers, and combinations thereof. In one particular embodiment, the mixture includes an uncured resin material configured to form a phenolic resin bond material upon further processing.

[0120] The phenolic resin may be modified with a curing or crosslinking agent such as hexamethylenetetramine. At temperatures above about 90°C, some examples of hexamethylenetetramine may crosslink to form methylene and dimethylene amino crosslinks that aid in curing the resin. The hexamethylenetetramine may be uniformly dispersed throughout the resin. More specifically, the hexamethylenetetramine may be uniformly dispersed within the resin regions as a crosslinking agent. Even more specifically, the phenolic resin may contain resin regions with crosslinked domains having an average size of submicrons.

[0121] Other materials, such as fillers, can be included in the mixture. The fillers may or may not be present in the final formed abrasive article. After forming the mixture, the process of forming the abrasive article can further include forming a substrate comprising abrasive particles contained in a binding material. The substrate is an unfinished body that may undergo further processing before the final formed abrasive article is formed. Forming the substrate can include techniques such as pressing, molding, casting, printing, spraying, and combinations thereof. In one particular embodiment, forming the substrate can include pressing the mixture into a particular shape, for example, performing a pressing operation to form a substrate in the form of a grinding wheel.

[0122] It will also be understood that one or more reinforcing materials may be included within or between portions of the mixture to create a composite including one or more abrasive portions (i.e., abrasive particles contained within a binding material, as well as porosity, fillers, etc.) and a reinforcing portion composed of the reinforcing material. Some suitable examples of reinforcing materials include woven materials, nonwoven materials, glass fibers, fibers, natural materials, synthetic materials, inorganic materials, organic materials, or any combination thereof. As used herein, terms such as "reinforced" or "reinforcement" refer to a separate layer or portion of reinforcing material that is different from the binding material and abrasive material used to create the abrasive portion. Terms such as "internal reinforcement" or "internally reinforced" indicate that these components are within or embedded within the body of the abrasive article. In cut-off wheels, the internal reinforcement may be in the shape of a disk, for example, with a central opening to accommodate the arbor hole of the wheel. In some wheels, the reinforcing material extends from the arbor hole to the periphery of the body. In others, the reinforcing material can extend from the periphery of the body to a point just below the flange used to secure the body. Some abrasive articles may be "zone reinforced" with (internal) fiber reinforcement around the arbor hole and flange area of ​​the body (approximately 50% of the body diameter).

[0123] After forming a mixture having the desired components and applying the mixture to the desired processing equipment, the process can continue by treating the mixture to form the final formed abrasive article. Some suitable examples of treatments can include curing, heating, sintering, crystallizing, polymerizing, pressing, and combinations thereof. In one example, the process can include bond batching, mixing the abrasive particles with a bond material or bond precursor material, filling a mold, pressing, and heating or curing the mixture.

[0124] After the treatment process is complete, an abrasive article, such as abrasive article 400, is formed, including abrasive particles and any other additives contained within the bond material.

[0125] 6 includes a cross-sectional view of a coated abrasive article 600 including a substrate 601, a make coat 602 overlying the substrate 601, and abrasive particles 210. The coated abrasive article 600 can optionally include fillers, additives, or any combination thereof. A size coat 603 covers and bonds the abrasive particles 210 and the make coat 602. In another embodiment, abrasive particles 200 can be used or combined with abrasive particles 210 in forming the coated abrasive article 600.

[0126] In some embodiments, the substrate 601 can include organic materials, inorganic materials, and combinations thereof. In certain examples, the substrate 601 can include a woven material. However, the substrate 601 can also be made from a nonwoven material. Particularly suitable substrate materials can include organic materials including polymers, particularly polyesters, polyurethanes, polypropylene, polyimides such as KAPTON from DuPont, paper, or any combination thereof. Some suitable inorganic materials can include metals, metal alloys, particularly copper, aluminum, and steel foils, and combinations thereof.

[0127] The make coat 602 can be applied to the surface of the substrate 601 in a single process, or alternatively, the abrasive particles 210 can be combined with the make coat 602 material and the combination of the make coat 602 and abrasive particles 210 applied to the surface of the substrate 601 as a mixture. In certain instances, controlled deposition or placement of the abrasive particles 210 in the make coat 602 by separating the process of applying the make coat 602 from the process of depositing the abrasive particles 210 in the make coat 602 may be more preferred. It is still contemplated that such processes may be combined. Suitable materials for the make coat 602 can include organic materials, particularly polymeric materials including, for example, polyester, epoxy resin, polyurethane, polyamide, polyacrylate, polymethacrylate, polyvinyl chloride, polyethylene, polysiloxane, silicone, cellulose acetate, nitrocellulose, natural rubber, starch, shellac, and mixtures thereof. In one embodiment, the make coat 602 can include a polyester resin. The coated substrate can then be heated to cure the resin and bond the abrasive particles 210 to the substrate 601. Generally, the coated substrate 601 can be heated to a temperature of about 100° C. to less than about 250° C. during this curing process.

[0128] After the make coat 602 is fully formed with the abrasive particles 210 contained therein, a size coat 603 can be formed to overly and bond the abrasive particles 210 onto the make coat 602 and the substrate 601. The size coat 603 can include organic materials and may be made essentially of polymeric materials, including polyesters, epoxy resins, polyurethanes, polyamides, polyacrylates, polymethacrylates, polyvinyl chloride, polyethylene, polysiloxanes, silicones, cellulose acetate, nitrocellulose, natural rubber, starch, shellac, and mixtures thereof, among others.

[0129] Many different aspects and embodiments are possible. Some of these aspects and embodiments are described herein. After reading this specification, those skilled in the art will understand that these aspects and embodiments are merely illustrative and do not limit the scope of the invention. An embodiment may follow any one or more of the embodiments listed below.

[0130] Embodiment Embodiment 1. Abrasive particles, The main body is The core and a coating over at least a portion of the core, a lithium / silicon percentage ratio in the range of at least 0.01% to no more than 25%; a potassium / silicon percentage ratio within the range of at least 0.01% to no more than 40%; A sodium / silicon percentage ratio in the range of at least 0.01% to no more than 40%, or and a coating comprising at least one of any combination thereof.

[0131] Embodiment 2. The abrasive particle of embodiment 1, wherein the lithium / silicon percentage ratio is at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, or at least 0.1%, or at least 0.2%, or at least 0.3%, or at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%, or at least 1.6%, or at least 1.8%, or at least 2.0%, or at least 2.2%, or at least 2.4%, or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%.

[0132] Embodiment 3. The abrasive article of embodiment 1, wherein the lithium / silicon percentage ratio is 24% or less, or 23% or less, or 22% or less, or 21% or less, or 20% or less, or 19% or less, or 18% or less, or 17% or less, or 16% or less, or 15% or less, or 14% or less, or 13% or less, or 12% or less, or 11% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less.

[0133] Embodiment 4. The coating comprises at least 0.01 wt.%, or at least 0.02 wt.%, at least 0.03 wt.%, at least 0.04 wt.%, at least 0.05 wt.%, at least 0.06 wt.%, at least 0.07 wt.%, at least 0.08 wt.%, or at least 0.09 wt.%, or at least 0.1 wt.%, or at least 0.15 wt.%, or at least 0.2 wt.%, or at least 0.25 wt.%, or at least 0.3 wt.%, or at least 0.35 wt.%, or at least 0.4 wt.%, or at least 0.5 wt.%, or at least 0.6 wt.%, or at least 0.7 wt.%, or at least 0.8 wt.% 85. The abrasive particle of any one of embodiments 1 and 82-84, comprising a lithium content of at least 0.9 wt%, or at least 1.0 wt%, or at least 1.1 wt%, or at least 1.2 wt%, or at least 1.3 wt%, or at least 1.4 wt%, or at least 1.5 wt%, or at least 1.6 wt%, or at least 1.7 wt%, or at least 1.8 wt%, or at least 1.9 wt%, or at least 2.0 wt%, or at least 2.1 wt%, or at least 2.2 wt%, or at least 2.3 wt%, or at least 2.4 wt%, or at least 2.5 wt%, or at least 2.6 wt%.

[0134] Embodiment 5. The abrasive particle of any one of embodiments 1, 4, and 82-84, wherein the coating comprises a lithium content of 20% by weight or less, or 19% by weight or less, or 18% by weight or less, or 17% by weight or less, or 16% by weight or less, or 15% by weight or less, or 14% by weight or less, or 13% by weight or less, or 12% by weight or less, or 11% by weight or less, or 10% by weight or less, or 9% by weight or less, or 8% by weight or less, or 7% by weight or less, or 6% by weight or less, or 5% by weight or less, or 4% by weight or less, or 3% by weight or less, or 2% by weight or less.

[0135] Embodiment 6. The abrasive particle of any one of embodiments 1, 4-5, and 82-84, wherein the coating comprises a silicon content of at least 80 wt%, at least 81 wt%, at least 82 wt%, at least 83 wt%, at least 84 wt%, at least 85 wt%, at least 86 wt%, at least 87 wt%, at least 88 wt%, at least 89 wt%, at least 90 wt%, at least 91 wt%, at least 92 wt%, at least 93 wt%, at least 94 wt%, or at least 95 wt%.

[0136] Embodiment 7. The abrasive particle of any one of embodiments 1, 4-6, and 82-84, wherein the coating comprises a silicon content of 99% by weight or less, 98% by weight or less, 97% by weight or less, or 96% by weight or less.

[0137] Embodiment 8. The potassium / silicon percentage ratio is at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, or at least 0.1%, or at least 0.2%, or at least 0.3%, or at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%, or at least 1.6%, or at least 1.8%, or at least 2.0%, or at least 2.2%, or at least 2.4%, or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.1%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%.

[0138] Embodiment 9. The abrasive particle of embodiment 1, wherein the potassium / silicon percentage ratio is 39% or less, or 38% or less, or 37% or less, or 36% or less, or 35% or less, or 34% or less, or 33% or less, or 32% or less, or 31% or less, or 30% or less, or 29% or less, or 28% or less, or 27% or less, or 26% or less, or 25% or less, or 24% or less, or 23% or less, or 22% or less, or 21% or less, or 20% or less, or 19% or less, or 18% or less, or 17% or less, or 16% or less, or 15% or less, or 14% or less, or 13% or less, or 12% or less, or 11% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less.

[0139] Embodiment 10. The abrasive particle of any one of embodiments 1 and 82-84, wherein the coating comprises a potassium content of at least 0.01 wt%, or at least 0.02 wt%, at least 0.03 wt%, at least 0.04 wt%, at least 0.05 wt%, at least 0.06 wt%, at least 0.07 wt%, at least 0.08 wt%, or at least 0.09 wt%, or at least 1 wt%, at least 2 wt%, at least 3 wt%, at least 4 wt%, at least 5 wt%, at least 6 wt%, at least 7 wt%, at least 8 wt%, at least 9 wt%, or at least 10 wt%.

[0140] Embodiment 11. The abrasive particle of any one of embodiments 1, 10, and 82-84, wherein the coating comprises a potassium content of 30% by weight or less, 29% by weight or less, or 28% by weight or less, or 27% by weight or less, or 26% by weight or less, or 25% by weight or less, or 24% by weight or less, or 23% by weight or less, or 22% by weight or less, or 21% by weight or less, or 20% by weight or less, or 19% by weight or less, or 18% by weight or less, or 17% by weight or less, or 16% by weight or less, or 15% by weight or less, or 14% by weight or less, or 13% by weight or less, or 12% by weight or less, or 11% by weight or less, or 10% by weight or less, or 9% by weight or less, or 8% by weight or less, or 7% by weight or less.

[0141] Embodiment 12. The coating has a viscosity of 39% or less, or 38% or less, or 37% or less, or 36% or less, or 35% or less, or 34% or less, or 33% or less, or 32% or less, or 31% or less, or 30% or less, or 29% or less, or 28% or less, or 27% or less, or 26% or less, or 25% or less, or 24% or less, or 23% or less, or 22% or less, or 21% or less, or 20% or less, or 19% or less, or 18% or less. 85. The abrasive particle of any one of embodiments 1 and 82-84, comprising a potassium / silicon percent ratio of 0.01% or less, or 17% or less, or 16% or less, or 15% or less, or 14% or less, or 13% or less, or 12% or less, or 11% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less, or 2% or less, or 1% or less, or 0.5% or less.

[0142] Embodiment 13. The coating has at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.06%, at least 0.07%, at least 0.08%, at least 0.1%, at least 0.2%, at least 0.3%, at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.2%, or at least 1.4%, or at least 1.6%, or at least 1.8%, or at least 2.0%, or 85. The abrasive particle of any one of embodiments 1, 12, and 82-84, comprising a sodium / silicon percent ratio of at least 2.2%, or at least 2.4%, or at least 2.6%, or at least 2.8%, or at least 3.0%, or at least 3.2%, or at least 3.4%, or at least 3.6%, or at least 3.8%, or at least 4.0%, or at least 4.2%, or at least 4.4%, or at least 4.6%, or at least 4.8%, or at least 5.0%, or at least 5.2%, or at least 5.4%, or at least 5.5%.

[0143] Embodiment 14. The abrasive particle of any one of embodiments 1, 12, 13, and 82-84, wherein the coating comprises a sodium content of 30% by weight or less, 29% by weight or less, or 28% by weight or less, or 27% by weight or less, or 26% by weight or less, or 25% by weight or less, or 24% by weight or less, or 23% by weight or less, or 22% by weight or less, or 21% by weight or less, or 20% by weight or less, or 19% by weight or less, or 18% by weight or less, or 17% by weight or less, or 16% by weight or less, or 15% by weight or less, or 14% by weight or less, or 13% by weight or less, or 12% by weight or less, or 11% by weight or less, or 10% by weight or less, or 9% by weight or less, or 8% by weight or less, or 7% by weight or less, or 6% by weight or less, or 5% by weight or less, or 4% by weight or less, or 3% by weight or less, or 2% by weight or less.

[0144] Embodiment 15. The abrasive particle of any one of embodiments 1, 12-14, and 82-84, wherein the coating comprises a sodium content of at least 0.01 wt.%, or at least 0.05 wt.%, or at least 0.1 wt.%, or at least 0.2 wt.%, or at least 0.3 wt.%, or at least 0.5 wt.%, or at least 1.0 wt.%, or at least 1.5 wt.%, or at least 2.0 wt.%.

[0145] Embodiment 16. The coating contains a sodium content, measured in weight percent, that is 10 times or less than the lithium content, or the coating contains a sodium content that is 8 times or less than the lithium content, or the coating contains a sodium content that is 6 times or less than the lithium content, or the coating contains a sodium content that is 4 times or less than the lithium content, or the coating contains a sodium content that is 3 times or less than the lithium content, or the coating contains a sodium content that is 2.8 times or less than the lithium content, or the coating contains a sodium content that is 2.5 times or less than the lithium content, or the coating contains a sodium content that is 2.2 times or less than the lithium content, or the coating contains a sodium content that is 2 times or less than the lithium content, or the coating contains a sodium content that is 1.8 times or less than the lithium content. 8. The abrasive particle of any one of embodiments 1 and 4-7, wherein the coating comprises a sodium content that is 1.5 times or less than the lithium content, or wherein the coating comprises a sodium content that is 1.3 times or less than the lithium content, or wherein the coating comprises a sodium content that is 0.9 times or less than the lithium content, or wherein the coating comprises a sodium content that is 0.6 times or less than the lithium content, or wherein the coating comprises a sodium content that is 0.3 times or less than the lithium content, or wherein the coating comprises a sodium content that is 0.2 times or less than the lithium content, or wherein the coating comprises a sodium content that is 0.1 times or less than the lithium content, or wherein the coating comprises a sodium content that is 0.05 times or less than the lithium content, or wherein the coating comprises a sodium content that is 0.01 times or less than the lithium content.

[0146] Embodiment 17. The coating contains a sodium content, measured in weight percent, that is 10 times or less than the potassium content, or the coating contains a sodium content that is 8 times or less than the potassium content, or the coating contains a sodium content that is 6 times or less than the potassium content, or the coating contains a sodium content that is 4 times or less than the potassium content, or the coating contains a sodium content that is 3 times or less than the potassium content, or the coating contains a sodium content that is 2.8 times or less than the potassium content, or the coating contains a sodium content that is 2.5 times or less than the potassium content, or the coating contains a sodium content that is 2.2 times or less than the potassium content, or the coating contains a sodium content that is 2 times or less than the potassium content, or the coating contains a sodium content that is 1.8 times or less than the potassium content. 12. The abrasive particle of any one of embodiments 1, 10, and 11, wherein the coating comprises a sodium content that is 1.5 times or less than the potassium content, or wherein the coating comprises a sodium content that is 1.3 times or less than the potassium content, or wherein the coating comprises a sodium content that is 0.9 times or less than the potassium content, or wherein the coating comprises a sodium content that is 0.6 times or less than the potassium content, or wherein the coating comprises a sodium content that is 0.3 times or less than the potassium content, or wherein the coating comprises a sodium content that is 0.2 times or less than the potassium content, or wherein the coating comprises a sodium content that is 0.1 times or less than the potassium content, or wherein the coating comprises a sodium content that is 0.05 times or less than the potassium content, or wherein the coating comprises a sodium content that is 0.01 times or less than the potassium content.

[0147] Embodiment 18. The abrasive particles of any one of embodiments 1, 4-7, and 16, wherein the lithium comprises a lithium-containing compound.

[0148] Embodiment 19. The abrasive particle of embodiment 18, wherein the lithium-containing compound comprises an oxide.

[0149] Embodiment 20. The abrasive particle of embodiment 18, wherein the lithium-containing compound comprises lithium oxide.

[0150] Embodiment 21. The abrasive particles of any one of embodiments 1 and 82-84, wherein the silicon comprises a silicon-containing compound.

[0151] Embodiment 22. The abrasive particle of embodiment 21, wherein the silicon-containing compound comprises an oxide.

[0152] Embodiment 23. The abrasive particles of embodiment 21, wherein the silicon-containing compound comprises silicon dioxide.

[0153] Embodiment 24. The abrasive particles of embodiment 1, wherein the potassium comprises a potassium-containing compound.

[0154] Embodiment 25. The abrasive particle of embodiment 24, wherein the potassium-containing compound comprises an oxide.

[0155] Embodiment 26. The abrasive particle of embodiment 24, wherein the potassium-containing compound comprises potassium oxide.

[0156] Embodiment 27. The abrasive particles of embodiment 1, wherein the sodium comprises a sodium-containing compound.

[0157] Embodiment 28. The abrasive particle of embodiment 27, wherein the sodium-containing compound comprises an oxide.

[0158] Embodiment 29. The abrasive particle of embodiment 27, wherein the sodium-containing compound comprises sodium oxide.

[0159] Embodiment 30. An abrasive article according to embodiment 1, wherein the core comprises a ceramic material.

[0160] Embodiment 31. The abrasive particle of any one of embodiments 1 and 82-84, wherein the core comprises an oxide, a carbide, a nitride, a superabrasive, a boride, an oxycarbide, an oxynitride, a carbon-based material, an agglomerate, an aggregate, a shaped abrasive particle, a microcrystalline material, a nanocrystalline material, or any combination thereof.

[0161] Embodiment 32. An abrasive particle according to any one of embodiments 1 and 82-84, wherein the core comprises an oxide selected from the group consisting of alumina, silica, zirconia, or any combination thereof.

[0162] Embodiment 33. An abrasive particle according to any one of embodiments 1 and 82-84, wherein the core comprises fused alumina, sol-gel alumina, nanocrystalline alumina, brown fused alumina, or any combination thereof.

[0163] Embodiment 34. Abrasive particles described in any one of embodiments 1 and 82 to 84, wherein the core comprises a polycrystalline material made from a plurality of microcrystalline abrasive grains, the microcrystalline abrasive grains having an average domain size of at least 50 nm and no more than 3 mm.

[0164] Embodiment 35. An abrasive particle according to any one of embodiments 1 and 82 to 84, wherein the core comprises at least one of a single crystalline phase, a polycrystalline phase, an amorphous phase, or any combination thereof.

[0165] Embodiment 36. An abrasive particle according to any one of embodiments 1 and 82-84, wherein the coating comprises a total crystalline content of 99% by volume or less, or 97% by volume or less, or 90% by volume or less, or 80% by volume or less, or 70% by volume or less, or 60% by volume or less, or 50% by volume or less, or 40% by volume or less, or 30% by volume or less, or 20% by volume or less, or 10% by volume or less, or 8% by volume or less, or 5% by volume or less, or 3% by volume or less, or 2% by volume or less, or 1% by volume or less of the total volume of the coating.

[0166] Embodiment 37. The core has a density of at least 2.10 g / cm 3 , at least 2.20 g / cm 3, 2.30g / cm 3 , at least 2.40 g / cm 3 , at least 2.50 g / cm 3 , at least 2.60 g / cm 3 , at least 2.70 g / cm 3 , 2.80g / cm 3 , at least 2.90 g / cm 3 , at least 3.00 g / cm 3 , at least 3.10 g / cm 3 , at least 3.20 g / cm 3 , at least 3.30 g / cm 3 , at least 3.40 g / cm 3 , 3.50g / cm 3 , at least 3.55 g / cm 3 , at least 3.60 g / cm 3 , at least 3.65 g / cm 3 , at least 3.70 g / cm 3 , at least 3.75 g / cm 3 , at least 3.80 g / cm 3 , at least 3.85 g / cm 3 , at least 3.90 g / cm 3 , or at least 3.95 g / cm 3 85. The abrasive particle of any one of embodiments 1 and 82-84, comprising a density of

[0167] Embodiment 38. The core has a density of 5.80 g / cm 3 Below, 5.70g / cm 3 Below, 5.60g / cm 3 Below 5.50g / cm 3 Below, 5.40g / cm 3 Below, 5.30g / cm 3 Below, 5.20g / cm 3 Below, 5.10g / cm 3 Below 5.00g / cm 3 Below, 4.90g / cm 3 Below, 4.80g / cm 3 Below, 4.70g / cm 3 Below, 4.60g / cm 3 Below 4.50g / cm 3Below, 4.40g / cm 3 Below, 4.30g / cm 3 Below 4.20g / cm 3 Below, 4.10g / cm 3 Below 4.00g / cm 3 Below, 3.97g / cm 3 85. The abrasive particle of any one of embodiments 1 and 82-84, comprising the following density:

[0168] Embodiment 39. An abrasive particle according to any one of embodiments 1 and 82-84, wherein the core comprises a density of at least 80% of its theoretical density, at least 85%, at least 88%, at least 90%, at least 92%, at least 95%, or at least 98% of its theoretical density.

[0169] Embodiment 40. An abrasive particle according to any one of embodiments 1 and 82 to 84, wherein the core has a porosity of 10% by volume or less, 9% by volume or less, 8% by volume or less, 7% by volume or less, 6% by volume or less, 5% by volume or less, 4% by volume or less, 3% by volume or less, 2% by volume or less, or 1% by volume or less, based on the total volume of the core.

[0170] Embodiment 41. An abrasive particle according to any one of embodiments 1 and 82-84, wherein the core is essentially free of pores.

[0171] Embodiment 42. An abrasive particle according to any one of embodiments 1 and 82 to 84, wherein the coating comprises a dry material.

[0172] Embodiment 43. An abrasive particle according to any one of embodiments 1 and 82 to 84, wherein the coating comprises an unsintered material.

[0173] Embodiment 44. An abrasive particle according to any one of embodiments 1 and 82 to 84, wherein the coating has an average coating thickness of at least 10 nm, at least 12 nm, at least 15 nm, at least 18 nm, at least 20 nm, at least 25 nm, at least 28 nm, at least 30 nm, at least 32 nm, at least 35 nm, at least 38 nm, at least 40 nm, at least 43 nm, at least 45 nm, at least 48 nm, at least 50 nm, at least 52 nm, at least 55 nm, at least 58 nm, at least 60 nm, at least 63 nm, at least 68 nm, at least 70 nm, at least 74 nm, at least 76 nm, at least 80 nm, at least 83 nm, at least 86 nm, or at least 90 nm.

[0174] Embodiment 45. Abrasive particles according to any one of embodiments 1 and 82 to 84, wherein the coating has an average coating thickness of 150 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, 110 nm or less, or 100 nm or less.

[0175] Embodiment 46. An abrasive particle according to any one of embodiments 1 and 82-84, wherein the coating has a thickness standard deviation of 200% or less of the average thickness, 150% or less of the average coating thickness, 100% or less, 80% or less, 50% or less, 49% or less, 47% or less, 44% or less, 42% or less, 40% or less, 38% or less, 36% or less, 34% or less, 33% or less, 31% or less, 30% or less, 29% or less, 27% or less, 25% or less, 23% or less, 21% or less, 20% or less, 19% or less, 18% or less, 17% or less, 16% or less, 14% or less, 12% or less, 11% or less, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.8% or less, 0.7% or less, or 0.5% or less.

[0176] Embodiment 47. An abrasive particle described in any one of embodiments 1 and 82 to 84, wherein the coating has a thickness standard deviation of at least 0.001% of the average thickness, at least 0.05%, at least 0.08%, at least 0.1%, at least 0.2%, at least 0.3%, at least 0.4%, at least 0.5%, at least 0.7%, at least 0.8%, at least 0.9%, at least 1%, at least 1.2%, at least 1.5%, at least 1.8%, at least 2%, at least 2.2%, at least 2.5%, at least 2.8%, at least 3%, at least 4%, or at least 5% of the average thickness of the coating.

[0177] Embodiment 48. An abrasive particle according to any one of embodiments 1 and 82 to 84, wherein the coating comprises an amorphous phase content in the range of at least 90% by weight based on the total weight of the coating.

[0178] Embodiment 49. An abrasive particle according to any one of embodiments 1 and 82 to 84, wherein the coating consists essentially of an amorphous phase.

[0179] Embodiment 50. The abrasive particle of any one of embodiments 1 and 82-84, further comprising a coating content of at least 0.01 wt.%, based on the total weight of the core, at least 0.02 wt.%, at least 0.03 wt.%, at least 0.04 wt.%, at least 0.05 wt.%, at least 0.06 wt.%, at least 0.07 wt.%, at least 0.08 wt.%, at least 0.09 wt.%, at least 0.1 wt.%, at least 0.15 wt.%, at least 0.16 wt.%, at least 0.17 wt.%, at least 0.18 wt.%, at least 0.19 wt.%, at least 0.2 wt.%, at least 0.25 wt.%, at least 0.26 wt.%, at least 0.27 wt.%, at least 0.28 wt.%, at least 0.29 wt.%, or at least 0.3 wt.%, based on the total weight of the core.

[0180] Embodiment 51. An abrasive particle according to any one of embodiments 1 and 82 to 84, further comprising a coating content of 1% or less by weight based on the total weight of the core, 0.9% or less by weight, 0.8% or less by weight, 0.7% or less by weight, 0.6% or less by weight, 0.55% or less by weight, 0.5% or less by weight, 0.48% or less by weight, 0.46% or less by weight, 0.45% or less by weight, 0.43% or less by weight, 0.42% or less by weight, 0.41% or less by weight, 0.4% or less by weight, 0.38% or less by weight, 0.37% or less by weight, 0.36% or less by weight, 0.35% or less by weight, or 0.34% or less by weight based on the total weight of the core.

[0181] Embodiment 52. An abrasive particle according to any one of embodiments 1 and 82 to 84, further comprising a ratio of average coating thickness to average core particle size, wherein this ratio is less than 1, 0.9 or less, 0.7 or less, 0.5 or less, 0.4 or less, 0.2 or less, 0.1 or less, 0.08 or less, 0.06 or less, 0.05 or less, 0.03 or less, 0.02 or less, 0.01 or less, 0.009 or less, 0.008 or less, 0.007 or less, 0.006 or less, 0.005 or less, 0.004 or less, 0.003 or less, 0.002 or less, or 0.1 or less.

[0182] Embodiment 53. An abrasive particle according to any one of embodiments 1 and 82 to 84, further comprising a ratio of average coating thickness to average core particle size, wherein this ratio is at least 0.0005, at least 0.0007, at least 0.0009, at least 0.001, at least 0.002, at least 0.003, at least 0.004, at least 0.005, at least 0.006, at least 0.007, at least 0.008, at least 0.009, at least 0.01, at least 0.02, or at least 0.03.

[0183] Embodiment 54. An abrasive particle according to any one of embodiments 1 and 82-84, wherein the coating further comprises at least one silane-containing composition.

[0184] Embodiment 55. An abrasive particle according to embodiment 54, wherein the coating comprises at least 0.02% by weight of the silane-containing compound relative to the total weight of the coating, or at least 0.5% by weight, or at least 1% by weight, or at least 2% by weight, or at least 3% by weight, or at least 4% by weight, or at least 5% by weight, or at least 6% by weight, or at least 7% by weight, or at least 8% by weight, or at least 9% by weight, or at least 10% by weight of the silane-containing compound relative to the total weight of the coating, or further wherein the coating comprises 25% by weight or less of the silane-containing compound relative to the total weight of the coating, for example, 20% by weight or less, or 18% by weight or less, or 16% by weight or less, or 14% by weight or less, or 12% by weight or less, or 10% by weight or less of the silane-containing compound relative to the total weight of the coating.

[0185] Embodiment 56. The abrasive particles of any one of embodiments 1 and 82-84, wherein the abrasive particles have an average particle size of at least at least 10 microns, at least 30 microns, at least 40 microns, at least 50 microns, at least 60 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 120 microns, at least 140 microns, at least 150 microns, at least 170 microns, at least 180 microns, at least 200 microns, at least 210 microns, at least 230 microns, at least 250 microns, at least 260 microns, at least 270 microns, at least 290 microns, at least 300 microns, at least 320 microns, at least 340 microns, at least 350 microns, at least 360 microns, at least 380 microns, at least 400 microns, at least 420 microns, at least 430 microns, at least 440 microns, at least 450 microns, at least 460 microns, at least 470 microns, at least 490 microns, or at least 500 microns.

[0186] Embodiment 57. Abrasive particles according to any one of embodiments 1 and 82 to 84, wherein the abrasive particles have an average particle size of 3 mm or less, e.g., 2 mm or less, 1.8 mm or less, 1.6 mm or less, 1.5 mm or less, 1.2 mm or less, 1 mm or less, 900 microns or less, 850 microns or less, 830 microns or less, 800 microns or less, 750 microns or less, 700 microns or less, 650 microns or less, 600 microns or less, 550 microns or less, 500 microns or less, 450 microns or less, or 400 microns or less.

[0187] Embodiment 58. A fixed abrasive article comprising abrasive particles according to any one of embodiments 1 and 82 to 84.

[0188] Embodiment 59. A fixed abrasive article as described in embodiment 58, wherein the abrasive article has a wet retention value of at least 70%, for example, at least 71%, or at least 72%, or at least 73%, or at least 74%, or at least 75%, or at least 76%, or at least 77%, or at least 78%, or at least 79%, or at least 80%, or at least 81%, or at least 82%, or at least 83%, or at least 84%, or even at least 85%.

[0189] Embodiment 60. A batch of abrasive articles comprising abrasive particles according to any one of embodiments 1 and 82-84.

[0190] Embodiment 61. A batch of an abrasive article according to embodiment 60, wherein the batch comprises at least 10% by weight, or at least 20% by weight, or at least 30% by weight, or at least 40% by weight, or at least 50% by weight, or at least 60% by weight, or at least 70% by weight, or at least 80% by weight, or at least 90% by weight of the abrasive particles of embodiment 1, based on the total weight of the abrasive particles in the batch.

[0191] Embodiment 62. A batch of abrasive particles according to embodiment 60, wherein the batch consists essentially of the abrasive particles of embodiment 1.

[0192] Embodiment 63. A batch of abrasive particles according to embodiment 60, wherein the abrasive particles comprise any one or more combinations of the features described in this embodiment or any embodiment herein.

[0193] Embodiment 64. A method for forming an abrasive particle or a plurality of abrasive particles, comprising: Providing a core and forming a coating over at least a portion of the core, wherein the coating comprises any one or more features of any of the embodiments described herein.

[0194] Embodiment 65. The method of embodiment 64, wherein forming comprises heating the coating at a temperature of 800°C or less, or 700°C or less, or 600°C or less, or 500°C or less, or 400°C or less, or 300°C or less, or 250°C or less.

[0195] Embodiment 66. The method of embodiment 64, wherein forming comprises heating the coating at a temperature of at least 20°C, or at least 30°C, or at least 40°C, or at least 50°C, or at least 60°C, or at least 70°C, or at least 80°C, or at least 90°C, or at least 100°C, or at least 110°C, or at least 120°C, or at least 130°C, or at least 140°C, or at least 150°C.

[0196] Embodiment 67. The method of embodiment 64, further comprising providing a silane-containing material, a silanol-containing material, or a combination thereof over the coating.

[0197] Embodiment 68. The method of embodiment 64, further comprising disposing the abrasive particle or particles in a fixed abrasive article.

[0198] Embodiment 69. The method of embodiment 64, further comprising disposing the abrasive particle or particles in a bonded abrasive article.

[0199] Embodiment 70. The method of embodiment 64, further comprising disposing the abrasive particle or particles in a bonded abrasive article comprising an organic bond material.

[0200] Embodiment 71. The method of embodiment 70, wherein the organic bonding material comprises at least one of a phenolic, an epoxy, a polyester, a cyanate ester, a shellac, a polyurethane, a polybenzoxazine, a polybismaleimide, a polyimide, a rubber, or a combination thereof.

[0201] Embodiment 72. Abrasive particles, The main body is The core and a coating over at least a portion of the core, the coating having a total crystalline content of 60 volume percent or less of the total volume of the coating; the coating comprises at least one silicate-containing compound and at least one silica-containing compound; Abrasive particles, the coating of which comprises a silicate / silica percentage ratio of at least 10% and not more than 1000%.

[0202] Embodiment 73. An abrasive particle according to any one of embodiments 72 and 82-84, wherein the coating comprises a total crystalline content of 50% by volume or less, or 40% by volume or less, or 30% by volume or less, or 20% by volume or less, or 10% by volume or less, or 8% by volume or less, or 5% by volume or less, or 3% by volume or less, or 2% by volume or less, or 1% by volume or less.

[0203] Embodiment 74. The abrasive particle of embodiment 72, wherein the silicate-containing compound comprises at least one of sodium silicate, potassium silicate, lithium silicate, or a combination thereof.

[0204] Embodiment 75. The abrasive particles of embodiment 72 or 84, wherein the silica-containing compound comprises silicon dioxide.

[0205] Embodiment 76. An abrasive particle according to any one of embodiments 72 and 82 to 84, wherein the coating comprises a silica-containing compound content of at least 1 wt%, or at least 5 wt%, or at least 10 wt%, or at least 15 wt%, or at least 20 wt%, or at least 30 wt%, or at least 40 wt%, or at least 50 wt%, or at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or at least 90 wt%, based on the total weight of the coating.

[0206] Embodiment 77. Abrasive particles according to any one of embodiments 72 and 82 to 84, wherein the coating comprises a silica-containing compound content of 99% by weight or less, or 95% by weight or less, or 90% by weight or less, or 80% by weight or less, or 70% by weight or less, or 60% by weight or less, or 50% by weight or less, or 40% by weight or less, or 30% by weight or less, or 20% by weight or less, or 10% by weight or less, based on the total weight of the coating.

[0207] Embodiment 78. An abrasive particle according to embodiment 72, wherein the coating comprises a silicate-containing compound content of at least 1 wt%, or at least 5 wt%, or at least 10 wt%, or at least 15 wt%, or at least 20 wt%, or at least 30 wt%, or at least 40 wt%, or at least 50 wt%, or at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or at least 90 wt%, based on the total weight of the coating.

[0208] Embodiment 79. Abrasive particles according to any one of embodiments 72 and 82 to 84, wherein the coating contains a silicate-containing compound content of 99% by weight or less, or 95% by weight or less, 90% by weight or less, 80% by weight or less, 70% by weight or less, 60% by weight or less, 50% by weight or less, 40% by weight or less, 30% by weight or less, 20% by weight or less, or 10% by weight or less, based on the total weight of the coating.

[0209] Embodiment 80. The abrasive particles of embodiment 72 or 79, wherein the silicate / silica percentage ratio is at least 15%, or at least 20%, or at least 25%, or at least 30%, or at least 35%, or at least 40%, or at least 45%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 100%.

[0210] Embodiment 81. The abrasive particles of embodiment 72 or 79, wherein the silicate / silica percent ratio is 1000% or less, or 900% or less, or 800% or less, or 700% or less, or 600% or less, or 500% or less, or 400% or less, or 300% or 200% or less, or 190% or less, or 180% or less, or 170% or less, or 60% or less, or 150% or less, or 140% or less, or 130% or less, or 120% or less, or 110% or less, or 100% or less, or 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less, or 15% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less.

[0211] Embodiment 82. Abrasive particles, a core comprising a ceramic material; a coating comprising silicon and oxygen covering at least a portion of the core; Nanoparticles and a binder material; An abrasive particle comprising: a coating comprising nanopores.

[0212] Embodiment 83. Abrasive particles, a core comprising a ceramic material including a magnetoplumbite phase; a coating over at least a portion of the core, Nanoparticles and a binder material; An abrasive particle comprising: a coating comprising nanopores.

[0213] Embodiment 84. An abrasive particle according to embodiment 82 or 23, wherein the nanoparticles comprise silica and the binder material comprises a silica-containing compound. [Example]

[0214] Example 1 A representative sample of abrasive particles was formed by first preparing a coating mixture containing 7.01 grams of silica available as DS-13 from Qingdao FUSO Co., Ltd., 2.65 grams of lithium silicate available as Lith Crys® A48 from Dongguan Songshi Chemical Co., Ltd., and 20.34 grams of DI water. The ratio of components in the mixture was 72 wt. % colloidal silica solution and 28 wt. % lithium silicate solution, with properties shown in Table 1. White alumina 38A (white fused alumina (α-A)) 12 O3>99%, 60 grit) particles were used as core particles and coated with the coating mixture by mixing 1000.0 grams of fused alumina particles with 13.0 grams of the coating mixture using a mixer for 1-5 minutes. The wet and coated abrasive particles were dried in a normal atmosphere at 150°C for 14 hours to form coated abrasive particles (i.e., Sample S1). The particles were unsintered and had a total crystalline content of 0% by volume relative to the total volume of the coating.

[0215] [Table 1]

[0216] ICP Analysis Technique. The following is the ICP analysis technique used herein to evaluate the composition of the coating, particularly the inorganic materials in the coating. ICP analysis was performed on the coating layer of Sample 1. The results are shown in Table 3. Sample 1 had 1.14 wt% Li and 45.62 wt% Si, a lithium / silicon percentage ratio of 2.9%, and a sodium / silicon ratio of 5.9%, based on the total weight of the coating. The analysis was performed by first weighing 20.0 grams of Sample S1 and adding 2 mL of hydrochloric acid, 0.5 mL of nitric acid, and 10 mL of hydrofluoric acid. The sample was then sealed in a digestion tank at 100°C for 1 hour. The sample was then filtered, and the filtrate was measured by ICP-OES using the instrument parameters shown in Table 2.

[0217] [Table 2]

[0218] [Table 3]

[0219] Example 2 A second representative example of coated particles, S2, was prepared according to the same procedure as S1 in Example 1, except that the coating mixture for the abrasive particles was 72 wt % colloidal silica solution and 28 wt % potassium silicate solution (available from Xingtai Dayang Chemical Co., Ltd. as DY-4.0), and had the properties listed in Table 4. The particles were unsintered and had a total crystalline content of 0 vol % relative to the total volume of the coating.

[0220] [Table 4]

[0221] ICP analysis was performed on the coating layer of S2, the results of which are shown in Table 5. Sample 2 had a potassium / silicon percentage ratio of about 3.2 to 7.7% and a sodium / silicon ratio of about 2.1% to 5.5%.

[0222] [Table 5]

[0223] Example 3 A third representative example of coated particles, S3, was prepared according to the same procedure as S1 in Example 1, except that the coating mixture for the abrasive particles was 80 wt % colloidal silica solution and 20 wt % sodium silicate solution (available from Xingtai Dayang Chemical Co., Ltd. as TPY-2.8), and had the properties listed in Table 6. The particles were unsintered and had a total crystalline content of 0 vol % relative to the total volume of the coating.

[0224] [Table 6]

[0225] ICP analysis was performed on the coating layer of S3, the results of which are shown in Table 7. Sample 3 had a sodium / silicon percentage ratio of about 5.3 to 17.6%.

[0226] [Table 7]

[0227] Example 4 Comparative coated particles CS1 were made by mixing white alumina 38A particles with silica, available as DS-13 from Qingdao FUSO Co., Ltd., for 3–5 minutes at a silica content of 0.1 wt % relative to the total weight of the alumina particles. A portion of the wet particles was sintered at 850°C for 15 minutes to form coated particle sample CS1, which had a total crystalline content of 63 vol % relative to the total volume of the coating.

[0228] Example 5 A second comparative coated particle, CS2, was made by mixing white alumina 38A particles with silica, available as DS-13 from Qingdao FUSO Co., Ltd., for 3 to 5 minutes at a silica content of 0.1 wt. % based on the total weight of the alumina particles. A portion of the wet particles was dried at 150°C for 14 hours to form coated abrasive particles, which had a total crystalline content of 0 vol. % based on the total volume of the coating.

[0229] Example 6 A third comparative coated particle, CS3, was made by first preparing a coating mixture containing 2.88 grams of potassium silicate solution available as DY-4.0 from Xingtai Dayang Chemical Co., Ltd., 10.38 grams of lithium silicate available as Lith Crys® A48 from Dongguan Songshi Chemical Co., and 16.74 grams of DI water. The ratio of components in the mixture was 78 wt. % lithium silicate solution and 22 wt. % potassium silicate solution, forming a coating mixture with the properties shown in Table 8. White alumina 38A (white fused alumina (α-A)) 12O3) particles were used as core particles and coated with the coating mixture by mixing 1000.0 grams of fused alumina particles with 13.0 grams of the coating mixture using a mixer for 1-5 minutes. The wet and coated abrasive particles were dried at 150°C for 14 hours to form coated abrasive particles (i.e., sample CS3). The particles were unsintered and had a total crystalline content of 0% by volume relative to the total volume of the coating.

[0230] [Table 8]

[0231] Example 7 A fourth comparative coated particle, CS4, was made by first creating a coating mixture containing 8.76 grams of sodium silicate solution available as TPY-2.8 from Xingtai Dayang Chemical Co., Ltd. and 21.24 grams of DI water. The components in the mixture were 100 wt.% sodium silicate with the properties listed in Table 9. White alumina 38A (white fused alumina (α-A)) 12 O3) particles were used as core particles and coated with the coating mixture by mixing 1000.0 grams of fused alumina particles with 13.0 grams of the coating mixture using a mixer for 1-5 minutes. The wet and coated abrasive particles were dried at 150°C for 14 hours to form coated abrasive particles (i.e., sample CS4). The particles were unsintered and had a total crystalline content of 0% by volume based on the total volume of the coating. The CS4 particles were unusable due to significant particle agglomeration, presumably due to the coating composition. Sample CS4 contained 19.98 wt% Na and 34.18 wt% Si based on the total weight of the coating. See particle agglomeration in Figure 7.

[0232] [Table 9]

[0233] Example 8 A fifth comparative coated particle, CS5, was made by first preparing a coating mixture containing 13.27 g of potassium silicate solution available as DY-4.0 from Xingtai Dayang Chemical Co., Ltd. and 16.73 grams of DI water. The components in the mixture were 100 wt. % potassium silicate with the properties in Table 10. White alumina 38A (white fused alumina (α-A)) 12 O3) particles were used as core particles and coated with the coating mixture by mixing 1000.0 grams of fused alumina particles with 13.0 grams of the coating mixture using a mixer for 1-5 minutes. The wet and coated abrasive particles were dried at 150°C for 14 hours to form coated abrasive particles (i.e., sample CS5). The particles were unsintered and had a total crystalline content of 0% by volume relative to the total volume of the coating.

[0234] [Table 10]

[0235] Example 9 The coated alumina particles of samples S1, S2, S3, CS1, CS2, CS3, CS4, and CS5 were further treated with 3-aminopropyltriethoxysilane and dried at 150° C. for 14 hours to form abrasive particles.

[0236] Example 10 Using the coated alumina particles of Example 3, abrasive wheels S1, S2, S3, CS1, CS2, and CS4 were formed using the corresponding abrasive particle samples.

[0237] The S1 abrasive wheel was fabricated using 74.3 grams of Sample S1 abrasive particles mixed with a binding mixture containing phenolic resin for 2 to 7 minutes until all of the Sample S1 abrasive particles were coated with the binding mixture, forming an abrasive mixture. The abrasive mixture was then molded and cold pressed to the desired size in a 300-ton press at room temperature to produce a green abrasive wheel. The green wheel was removed from the mold and heat-treated in an oven at 160°C for 15 hours to harden it.

[0238] All other abrasive wheels (including wheel S2, wheel S3, wheel CS1, wheel CS2, and wheel CS4) were formed using the same bond mixture composition as wheel S1 and were made according to the same process as wheel S1, except that each wheel used its corresponding abrasive particle listed above (i.e., wheel S2 contained S2 abrasive particles instead of S1 abrasive particles, wheel S3 contained S3 abrasive particles instead of S1 abrasive particles, etc.). All wheels were formed to have the same abrasive wheel structure as wheel S1, including porosity content, abrasive particle content, and bond mixture content.

[0239] Dry and wet flexural strength (i.e., MOR) were tested for all abrasive wheels. To measure wet MOR, samples were immersed in boiling water for 2.5 hours before measurement. A summary of dry and wet MOR is summarized in Table 11. Wet retention was measured by dividing wet MOR by dry MOR and multiplying by 100. MOR was measured according to the disclosed three-point bend test.

[0240] [Table 11]

[0241] Surprisingly, it is noted that the abrasive wheels with dry coatings (i.e., S1, S2, and S3) were statistically equivalent in their performance when compared to the abrasive wheel CS1, which included abrasive particles with a sintered coating. Abrasive particles made by a lower temperature process can be beneficial for both sustainability and manufacturing.

[0242] Example 11 Another representative sample of abrasive particle S11 was formed as follows: Abrasive particle CG-2 was coated with the coating mixture described in Table 1 in a manner similar to that described in Example 1. The coated abrasive was further treated with 3-aminopropyltriethoxysilane and dried at 150°C for 14 hours to form abrasive particle S11. The properties and composition of the CG-1 and CG-2 abrasive particles are listed in Table 12. Abrasive particle sample S11 contains 1.18 wt% Li and 45.58 wt% Si in the coating based on the total weight of the coating.

[0243] [Table 12]

[0244] Density can be measured using a pycnometer AccuPyc II 1340 or equivalent as follows: 10 cm using an analytical balance with a readability of 0.1 mg or 0.0001 g. 3 Weigh out an amount of abrasive grain sample that can fill more than 75% of the volume of a sample cup having a nominal volume of 1000 kJ / cm2, and close the cap for absolute density testing.

[0245] LPD can be measured using a conventional abrasive particle loose packing density tester such as DMP-II type from ZSSM or an equivalent according to GB / T 20316.1-2009.

[0246] As disclosed in Table 12, the CG-2 abrasive grain exhibits lower hardness and increased toughness compared to the CG-1 abrasive grain.

[0247] Abrasive wheel samples S12-S14 and CS15-CS19 were made using respective blends containing abrasive particles and the same bond material (i.e., phenolic resin). The abrasive blends were molded and cold-pressed at room temperature in a 300-ton press to form green bodies, which were then removed from the mold and cured at 160°C for 15 hours. Samples S12-S14 were made using a blend of abrasive particles, including the abrasive particles of sample S11. All abrasive particles were 36 grit.

[0248] Sample S12 contained 46 vol.% abrasive particles (11 vol.% S11 particles, 26 vol.% single crystal alumina abrasive grains, and 9 vol.% green silicon carbide abrasive grains), 19 vol.% bond material, and 35 vol.% porosity relative to the total volume of the wheel body.

[0249] Sample S13 contained 46 vol.% abrasive particles (19 vol.% S11 particles, 18 vol.% single crystal alumina abrasive grains, and 9 vol.% green silicon carbide abrasive grains), 19 vol.% bond material, and 35 vol.% porosity relative to the total volume of the wheel body.

[0250] Sample S14 contained 46 vol.% abrasive particles (26 vol.% S11 particles, 11 vol.% single crystal alumina abrasive grains, and 9 vol.% green silicon carbide abrasive grains), 19 vol.% bond material, and 35 vol.% porosity relative to the total volume of the wheel body.

[0251] Samples CS15, CS16, and CS17 were made using CG-2 abrasive grain (uncoated). Sample CS15 contained 46% by volume of abrasive grain (11% by volume of CG-2 abrasive grain, 26% by volume of single crystal alumina abrasive grain, and 9% by volume of green silicon carbide abrasive grain), 19% by volume of bond material, and 35% by volume of porosity based on the total volume of the wheel body.

[0252] Sample CS16 (5WhitecutAG 36 G B37) contained 46 vol.% abrasive grains (19 vol.% CG-2 grains, 18 vol.% single crystal alumina grains, and 9 vol.% green silicon grains), 19 vol.% bond material, and 35 vol.% porosity relative to the total volume of the wheel body.

[0253] Sample CS17 contained 46 volume % abrasive particles (26 volume % CG-2 abrasive grains, 11 volume % single crystal alumina abrasive grains, and 9 volume % green silicon carbide abrasive grains) relative to the total volume of the wheel body, 19 volume % bond material including phenolic resin, and 35 volume % porosity.

[0254] Samples CS18 and CS19 were made using CG-1 abrasive grain. All abrasive grains were 36 grit. Sample CS18 contained 46% by volume abrasive particles (11% by volume CG-1 grain, 26% by volume single crystal alumina grain, and 9% by volume green silicon carbide grain), 19% by volume bond material, and 35% by volume porosity.

[0255] Sample CS19 contained 46 volume % abrasive particles (19 volume % CG-1 abrasive grains, 18 volume % single crystal alumina abrasive grains, and 9 volume % green silicon carbide abrasive grains) relative to the total volume of the wheel body, 19 volume % bond material including phenolic resin, and 35 volume % porosity.

[0256] Modulus of rupture (MOR) was tested on bar samples cut from wheel samples S12-S14 and CS15-CS19 under dry and wet conditions. MOR was tested according to embodiments herein. One set of bar samples was immersed in boiling water for 2.5 hours and then tested for MOR. The results were used as the wet MOR. The MOR tested on another set of bars that was not immersed was used as the dry MOR. Wet retention of the bar samples was determined by the formula: Wet Retention = (Dry MOR / Wet MOR) x 100 and is included in Table 13 below. Samples S12, S13, and S14 showed improved wet retention compared to samples CS15-CS19.

[0257] Wheel samples S12 to S14 and CS15 to CS19 were subjected to grinding tests using M2 steel as the workpiece. 3The G-ratios of the wheel samples at MRR in / s / mm are included in Table 13 below. Samples CS16 and CS17, despite their different abrasive particle contents, exhibited similar G-ratios and performed slightly better than CS15 (approximately a 6% increase in G-ratio). It should be understood that a higher G-ratio indicates better performance. Samples CS16 and CS17 had higher abrasive particle contents compared to sample CS18, but exhibited similar G-ratios. Sample CS19 exhibited a higher G-ratio compared to samples CS15-CS18. Samples S12 and CS15 had similar abrasive particle contents, but sample S12 exhibited an improved G-ratio compared to CS15. Samples S13 and CS19 exhibited similar wet retention, but sample S14 exhibited a higher G-ratio compared to sample CS19.

[0258] [Table 13]

[0259] Figure 8A includes a scanning electron microscope (SEM) image of a portion of NQ abrasive grain 810 including α-alumina crystallites 811. Figure 8B includes an SEM image of a portion of Whitecut abrasive grain 820 including a primary crystalline phase 822 and a secondary magnetoplumbite crystalline phase 821. Primary crystalline phase 822 includes α-alumina crystallites. Secondary phase 821 includes rare earth aluminates.

[0260] FIG. 9 includes plots of material removal rate (MRR) versus G-ratio for wheel samples S12-S14 and CS15-CS19. As illustrated, for a given material removal rate, wheel sample S14 exhibited a higher G-ratio than wheel samples S12, S13, and CS16-CS19. Sample S13 exhibited a similar G-ratio to CS19 over the material removal rates tested, and exhibited a higher G-ratio compared to samples S12 and CS15-CS18. Sample S12 exhibited an improved G-ratio compared to samples CS15-CS18.

[0261] Example 12 36-grit white alumina 38A abrasive grains were used to form abrasive particle samples CS20-CS22. 36-grit CQ-2 abrasive grains were used to form abrasive particle sample S24.

[0262] Sample CS20 was formed by mixing 1000.0 grams of abrasive particles with 13.0 grams of the formulation in Table 14 using a mixer. The wet abrasive particles were sintered at 850°C for 15 minutes to form coated abrasive grains, which were further treated with 3-aminopropyltriethoxysilane and dried at 150°C for 14 hours to form the coated abrasive particles of Sample CS20. Sample CS20 does not contain Li in the coating.

[0263] [Table 14]

[0264] Sample CS21 was formed by mixing 1000.0 grams of abrasive particles with 13.0 grams of the formulation in Table 15 using a mixer. The wet abrasive particles were air-dried at 150°C for 14 hours to form coated abrasive grains, which were further treated with 3-aminopropyltriethoxysilane and dried at 150°C for 14 hours to form the coated abrasive particles of Sample CS21. Sample CS21 contained 42.38 wt% Si and 4.36 wt% Li based on the total weight of the coating.

[0265] [Table 15]

[0266] Sample CS22 was formed by mixing 1000.0 grams of abrasive particles with 13.0 grams of the formulation in Table 15 using a mixer. The wet abrasive particles were sintered at 850°C for 15 minutes to form coated abrasive grains, which were further treated with 3-aminopropyltriethoxysilane and dried at 150°C for 14 hours to form the coated abrasive particles of Sample CS22. Sample CS22 contained 42.44 wt% Si and 4.32 wt% Li based on the total weight of the coating.

[0267] Sample CS23 was formed by using a mixer to mix 1000.0 grams of abrasive particles with 13.0 grams of the formulation in Table 14. The wet abrasive particles and coated abrasive particles were air-dried at 150°C for 14 hours to form coated abrasive grains, which were further treated with 3-aminopropyltriethoxysilane and dried at 150°C for 14 hours to form the coated abrasive particles of Sample CS23. Sample CS20 did not contain Li in the coating.

[0268] Sample S24 was formed by first treating the CQ-2 abrasive grain in the same manner as described for Sample S1. The coated abrasive grain was further treated with 3-aminopropyltriethoxysilane and dried at 150°C for 14 hours to form the coated abrasive particle of Sample S24. Sample S24 contained 45.43 wt% Si and 1.25 wt% Li, based on the total weight of the coating.

[0269] Figure 10A includes an SEM image showing a portion of the coating of sample S1 1010 at 50,000x magnification. Figure 10B includes a further enlargement (100,000x magnification) of the enclosed area 1011 of Figure 10A. As shown, the coating 1010 contains nanopores 1012 and appears relatively rough.

[0270] Figure 10C includes an SEM image showing a portion of the coating of sample CS20 1020 at 50,000x magnification. Figure 10D includes a further enlargement (100,000x magnification) of the enclosed area 1021 of Figure 10C. As shown, coating 1020 appears relatively smooth, smoother than coating 1010 of Figure 10A. No nanopores are observed within the selected area of ​​approximately 1.5 μm x 0.75 μm.

[0271] Figure 10E includes an SEM image showing a portion of the coating of sample CS21 1030 at 50,000x magnification. Figure 10F includes a further enlargement (100,000x magnification) of the enclosed area 1031 of Figure 10E. As shown, the coating 1030 appears relatively rough. No nanopores are observed within the selected area of ​​approximately 1.5 μm x 0.75 μm.

[0272] Figure 10G includes an SEM image showing a portion of the coating of sample CS22 1040 at 50,000x magnification. Figure 10H includes a further enlarged view (100,000x magnification) of the enclosed area 1041 of Figure 10G. As shown, coating 1030 appears relatively smooth, smoother than coating 1010 of Figure 10G. No nanopores are observed within the selected area of ​​approximately 1.5 μm x 0.75 μm.

[0273] Figure 11A includes an SEM image showing a portion of the coating of sample CS23 1110 at 100,000x magnification. Figure 11B includes a further enlargement (200,000x magnification) of the enclosed area 1111 of Figure 11A. As shown, the coating 1110 includes discrete silica nanoparticles 1112.

[0274] Figure 11C includes an SEM image showing a portion of the coating of sample CS24 1120 at 100,000x magnification. Figure 11D includes a further enlargement (200,000x magnification) of the boxed area 1121 in Figure 11C. As shown, coating 1120 includes nanopores 1122 and agglomerated nanoparticles 1123 comprising a silicate binder and silica nanoparticles. Coating 1120 includes fewer discrete nanoparticles compared to CS23.

[0275] Example 13 Representative abrasive particle samples S25-S30 and S34 were formed in the same manner as described for abrasive particle S11, except that the coating mixture compositions described in Table 16 were used. Table 16 further includes the Li and Si content (wt%) relative to the total coating weight, and the Li / Si weight content ratio. Samples S25-S30 and S34 contain about 0.8 wt% to 1 wt% Na relative to the total coating weight. The elemental content in the coating is determined by ICP, as described in the embodiments and Example 1 of this disclosure.

[0276] [Table 16]

[0277] Abrasive particle samples CS31 and CS32 were prepared using sodium silicate by dissolving 1000.0 grams of CG-2 abrasive in 13.0 grams of a coating mixture (NaO·nSiO in water). 2) (n=4.0); (concentration 30% SiO2) was mixed using a mixer for 1 to 5 minutes. The wet abrasive particles and coated abrasive particles were dried at 150°C for 14 hours to form coated abrasive particles CS31 and CS32. Abrasive particle samples CS31 and CS32 contained approximately 20% to 25% by weight of Na based on the total weight of the coating.

[0278] Polished bar specimens were formed using the abrasive particle samples described in Table 17 in the same manner as described in Example 11. All bar specimens contained 46 volume percent abrasive grain (19 volume percent coated CG-2 grain, 18 volume percent single crystal alumina grain, and 9 volume percent green silicon grain), 19 volume percent phenolic bond material, and 35 volume percent porosity, based on the total volume of the bar body. The modulus of rupture (MOR) and wet retention of the polished bar specimens were determined as described in Example 11, according to embodiments herein. Variation in wet retention between specimens made using CS31-CS32 may be due to particle agglomeration, as described in Example 7, when a sodium silicate solution is used as the coating solution.

[0279] [Table 17]

[0280] Example 14 Abrasive particle samples are formed and the specific surface area is measured according to embodiments herein using a Micromeritics® TriStar II Plus. The results are shown in Table 18.

[0281] Sample group S35 was formed, which included abrasive particle samples S35-1, S35-2, and S35-3 formed in the same manner as sample S11, except that CG-2 abrasive grains having average particle sizes of 24 grit, 60 grit, and 180 grit, respectively, were used as the cores.

[0282] Sample group S36 includes abrasive particle samples S36-1, S36-2, and S36-3 formed in the same manner as sample CS20, except that CG-2 abrasive grains having average particle sizes of 24 grit, 60 grit, and 180 grit, respectively, were used as the cores.

[0283] Sample group S37 includes abrasive particle samples S37-1, S37-2, and S37-3 formed in the same manner as sample CS21, except that CG-2 abrasive grains having average particle sizes of 24 grit, 60 grit, and 180 grit, respectively, were used as the cores.

[0284] Sample group S38 includes abrasive particle samples S38-1, S38-2, and S38-3 formed in the same manner as sample CS4, except that CG-2 abrasive grains having average particle sizes of 24 grit, 60 grit, and 180 grit, respectively, were used as the cores.

[0285] Sample group S39 includes abrasive particle samples S39-1, S39-2, and S39-3 formed in the same manner as sample CS23, except that CG-2 abrasive grains having average particle sizes of 24 grit, 60 grit, and 180 grit, respectively, were used as the cores.

[0286] [Table 18]

[0287] Example 15 Abrasive particle samples S40-S46 are formed using a colloidal silica solution and a lithium silicate solution or a coating mixture of lithium silicate solutions to have Li and Si contents (wt %) relative to the total weight of the coating as set forth below in Table 19. Polished bar specimens are formed using abrasive particle samples S40-S46, and the dry and wet MOR and wet retention of the bar specimens are tested in the same manner as described in Example 11.

[0288] [Table 19]

[0289] The preceding embodiments represent a departure from the prior art. The embodiments relate to abrasive particles that include a coating covering a core. In particular, the abrasive particles can include a thin conformal coating with improved average thickness and uniformity, which can improve the performance of the abrasive particles in fixed abrasives, such as reducing friction associated with their use in material removal operations, preventing aging, and facilitating chemical and mechanical bonding of the conformal layer to the surface of the abrasive particle (i.e., core particle). Furthermore, the abrasive particles can have improved bond strength and reduced moisture absorption and / or penetration, making them particularly suitable for use in coated abrasives and thin wheels.

[0290] Abrasive articles formed using the exemplary abrasive particles further exhibit improved performance and properties, such as wet MoR, G-ratio, and MMR, relative to abrasive articles including abrasive particles that include a dry coating. Without wishing to be bound by any theory, the improved properties and performance of the abrasive article may be facilitated by one or more characteristics of the abrasive particles, including one or more of the Li content, Si content, Na content, their content ratio, specific surface area, roughness, another chemical or morphological characteristic, or any combination thereof.

[0291] Benefits, other advantages, and solutions to problems have been described above with respect to specific embodiments. However, benefits, advantages, solutions to problems, and any features that may provide or enhance any benefit, advantage, or solution should not be construed as critical, necessary, or essential features of any or all claims. References herein to a material containing one or more components may be interpreted to include at least one embodiment in which the material consists essentially of the specified one or more components. The term "consisting essentially of" is to be interpreted to include compositions that include the specified materials and exclude all other materials except for minor contents (e.g., impurity contents) that do not significantly alter the properties of the material. Additionally, or alternatively, in certain non-limiting embodiments, any of the compositions specified herein may be essentially free of materials not expressly disclosed. It will be understood that embodiments herein include ranges of content of certain components within a material, and that the content of components within a given material totals 100%.

[0292] The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all elements and features of apparatus and systems that use the structures or methods described herein. Separate embodiments may be provided in combination in a single embodiment, and conversely, various features that are described for brevity in the context of a single embodiment may also be provided separately or in any subcombination. Furthermore, references to values ​​described in ranges include any and all values ​​within that range. Many other embodiments may become apparent to those skilled in the art only after reading this specification. Other embodiments may be utilized and derived from the present disclosure, such that structural substitutions, logical substitutions, or other changes may be made without departing from the scope of the present disclosure. Accordingly, the present disclosure should be considered illustrative, not restrictive.

Claims

1. Abrasive particles, The main body is The core and a coating over at least a portion of the core, the coating having a lithium content of at least 0.02 wt. % and no more than 20 wt. % based on the total weight of the coating.

2. Abrasive particles, The main body is The core and an abrasive particle comprising a body including a coating over at least a portion of the core, the coating comprising lithium and silicon, the silicon content being higher by weight than the lithium content by weight.

3. 3. The abrasive particle of claim 1, wherein the coating comprises a lithium content of at least 0.05 wt.%, at least 0.07 wt.%, at least 0.10 wt.%, or at least 0.15 wt.%, based on the total weight of the coating.

4. 3. The abrasive particle of claim 1, wherein the coating comprises a silicon content of at least 21%, at least 25%, at least 30%, at least 35%, or at least 38% by weight based on the total weight of the coating.

5. 3. The abrasive particle of claim 1, wherein the coating comprises a lithium / silicon percentage ratio in the range of at least 0.01% to no more than 250%, a sodium content of no more than 12% by weight relative to the total weight of the coating, or any combination thereof.

6. 3. The abrasive particle of claim 1 or 2, wherein the coating comprises an amorphous phase comprising lithium, silicon, or a combination thereof.

7. 3. The abrasive particle of claim 1, wherein the coating comprises oxygen.

8. 0.05 m ２ / g or more and 2.2m ２ 3. The abrasive particle of claim 1 or 2, comprising a specific surface area of ​​less than 1 / g.

9. 3. The abrasive particle of claim 1 or 2, wherein the coating comprises a lithium-containing material comprising Si, O, or a combination thereof.

10. The abrasive particle of claim 1 or 2, wherein the coating comprises nanoparticles, nanopores, or a combination thereof.

11. 11. The abrasive particle of claim 10, wherein the nanoparticles comprise silicon, oxygen, or a combination thereof.

12. 3. The abrasive particle of claim 1 or 2, wherein the core comprises a material comprising an oxide, a carbide, a nitride, a boride, an oxycarbide, an oxynitride, a silicate, or any combination thereof.

13. 3. The abrasive particle of claim 1, wherein the core comprises a ceramic material containing a magnetoplumbite phase.

14. 10. An abrasive article comprising a body comprising a bond material and abrasive particles contained in the bond material, the abrasive particles comprising the abrasive particles of claim 1 or 2.

15. 3. An abrasive article comprising: a binder material comprising an organic material; and abrasive particles contained in the binder material, wherein at least 10% of the volume content of the abrasive particles comprises the abrasive particles according to claim 1 or 2.

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