Abrasive article and methods of forming

Abstract

An abrasive article may include a body including a first abrasive region having a first average abrasive particle size and a second average abrasive particle size that is different from the first average particle size. The abrasive article may include a non-abrasive portion positioned between the first and second abrasive regions.

Description

[0001] ABRASIVE ARTICLE AND METHODS OF FORMING

[0002] TECHNICAL FIELD

[0003] The following is directed to an abrasive article and methods of forming the same, and particularly, to an abrasive article including abrasive regions having different abrasive particle sizes and methods of forming the same.

[0004] BACKGROUND ART

[0005] Abrasive tools have been used in various industries for the general function of removing material from a workpiece, including for example, sawing, drilling, polishing, cleaning, carving, and grinding. In the production of electronic devices, workpieces may include hard brittle materials, such as sapphire, quartz, SiC, GaN, and certain glass and ceramic materials. To grind the back surface of the semiconductor wafer efficiently, a grinding machine equipped with a rough grinding unit and a finish grinding unit is generally used. Generally, the article utilizes to conduct the rough grinding process is a bonded abrasive body or grindstone, and polishing pad is typically used to achieve surface finish of certain roughness.

[0006] Still, the industry continues to demand improved grindstone materials, capable of achieving improved grinding performance.

[0007] BRIEF DESCRIPTION OF THE DRAWINGS

[0008] 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.

[0009] FIG. 1 includes a top-down illustration of an abrasive article in accordance with an embodiment.

[0010] FIG. 2 includes a cross-sectional illustration of the abrasive article of FIG. 1.

[0011] FIG. 3 includes a flow chart illustrating a process of forming an abrasive article in accordance with an embodiment.

[0012] FIG. 4 includes an illustration of a double grinding operation according to an embodiment.

[0013] FIG. 5 includes a top-down illustration of an abrasive article.

[0014] FIGs. 6 to 11 include top-down illustrations of abrasive articles in accordance with embodiments described herein.

[0015] Skilled artisans 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 can be exaggerated relative to other elements to help improve understanding of embodiments of the invention. The use of the same reference symbols in different drawings indicates similar or identical items.

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0017] The following description, in combination with the figures, is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings.

[0018] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variation thereof, are intended to cover a non-exchisive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but can include other features not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inchisive-or and not to an exchisive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0019] 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 description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise.

[0020] 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 not intended to be limiting.

[0021] Embodiments herein relate to an abrasive article including a body including a plurality of concentric abrasive regions having different abrasive particle sizes. In particular, the body may include an inner abrasive region and an outer abrasive region, wherein the inner abrasive region may include a greater average abrasive particle size than the outer abrasive region. The abrasive article can have improved performance including material removal rate, surface finishing, service life, or any combination thereof. In a particular embodiment, the abrasive article may be particularly suited for grinding brittle and hard workpieces and achieving low surface roughness and / or total thickness roughness within a limited grinding time. Embodiments relate to a method of forming the abrasive article and using the abrasive article in material removal operations. An exemplary operation may include wafer grinding, disc grinding, or the like, or any combination thereof. In a particular example, a method of using the abrasive article may include grinding operations involving workpieces that are hard and brittle, such as sapphire, quartz, glass, ferrite, ceramics, silicon, SiC, GaN, or the like, or any combination thereof.

[0022] In an embodiment, the abrasive article may include a body including concentric abrasive regions that may be spaced apart from one another. In another embodiment, the body may include a plurality of abrasive regions and one or more non-abrasive portions, wherein the abrasive regions may be spaced apart from one another by one or more nonabrasive portions. In an example, adjacent abrasive regions may be spaced apart from one another by a non-abrasive portion. In a particular example, adjacent abrasive regions may be spaced apart entirely by a non-abrasive portion. In another embodiment, the body may include alternating non-abrasive portions and abrasive regions that may be concentric. For example, the abrasive regions and non-abrasive portions may have a substantially annular shape.

[0023] In an embodiment, the body may include a substrate, and the abrasive regions may be disposed on the substrate. The substrate may include a central opening that may facilitate installation of the abrasive article for material removal operations. In an example, abrasive regions may be radially spaced apart from one another and from the central opening. In a further example, each abrasive region may be attached to a surface of the substrate concentrically and spaced apart from one another. In a particular embodiment, the one or more non-abrasive portions may include a portion of the substrate. In a further embodiment, the substrate may have a rounded shape, such as a disc, a wheel, or the like. In another embodiment, the substrate may include a material including an organic material, an inorganic material, or a combination thereof. An exemplary material may include metal, such as aluminum alloy, steel, or the like, carbon fiber, a synthetic resin, such as engineering plastics, or any combination thereof.

[0024] In an embodiment, one or more or all of the abrasive regions may include a continuous annular body. For example, one or more or all the abrasive regions may be a separate integral body. Referring to FIG. 6, a representative abrasive article 600 includes a body 601 including annular abrasive regions 602, 603, and 604 that are not segmented.

[0025] In another embodiment, one or more or all of the plurality of abrasive regions may include abrasive segments. In an example, abrasive segments may be disposed on the substrate forming an annular abrasive region. Referring to FIG. 7, a representative abrasive article 700 includes a body 710 including annular abrasive regions 701, 702, and 703. The abrasive region 701 includes a plurality of segments 711 that are spaced apart and arranged in a manner such that the abrasive region 701 has an annular shape. Similar to the abrasive region 701, the abrasive region 702 has a substantially annular shape including a plurality of segments 722. In the illustrated embodiment, the abrasive region 703 is not segmented and has an integrated single body 733. In a further example, one or more or all the abrasive regions may include segments that may be spaced apart at a fixed interval. In another example, intervals between adjacent segments may be substantially the same in one or more or all the abrasive regions. In a particular example, at least some or all of the abrasive segments may abut one another forming an abrasive region. In another example, at least some or all of the abrasive segments may be spaced apart from one another in an abrasive region.

[0026] In a further embodiment, one or more abrasive regions may include segments that may be orientated at an angle relative to a diameter of the body. For example, a segment may include a longitudinal axis, wherein the longitudinal axis may form a right, an acute and / or an obtuse angle, with respect to a diameter of the body. For example, the length, width, diagonal, diameter, or another dimension may extend in the longitudinal axis’s of segments. Segments may be orientated such that the longitudinal axis’s may form an angle from 0° to 360° with respect to the outer diameter of the body. Referring to FIG. 9, a representative abrasive article 900 includes a body 901 including annular abrasive regions 902, 903, and 904. The abrasive region 903 includes segments 933 including a longitudinal axis 960. In the illustrated embodiment, the length of the segments 933 extends in the longitudinal axis 960. As illustrated, segments 933 are positioned in a manner such that the longitudinal axis 960 of segments 933 may form an acute angle 961 relative to the outer diameter 950 of the body 901. All the segments 933 are positioned along the circumference direction so that the abrasive region 903 is substantially annular.

[0027] The abrasive regions 902 and 904 include abrasive segments 922 and 944, respectively. Segments 922 and 944 may have a curved shape and arranged to form the annular abrasive regions 902 and 904, respectively. The segments 922 and 944 may have a greater dimension (i.e., length) extending in the circumferential direction of the body 901 and a smaller dimension (i.e., width) extending in a radial direction. As illustrated, segments 922 may have different lengths in the circumferential direction and longer segments may alternate with shorter segments. Segments 922 may have similar width in the radial direction. Similarly segments 944 may have different length in the circumferential direction and longer segments may alternate with shorter segments. Segments 922 may also have similar width in the radial direction.

[0028] Referring to FIG. 10, a representative abrasive article 1000 includes a body 1001 including annular abrasive regions 1002, 1003, and 1004. The abrasive region 1003 includes segments 1033 that are positioned along the circumferential direction of the body 100. The longitudinal axis’s 1060 of segments 1033 are angled with respect to the outer dimeter 1050. In the illustrated embodiments, segments 1033 are oriented differently such that the longitudinal axis’s 1060 of adjacent segments intersect. The abrasive regions 1002 and 1004 include curved segments 1022 and 1044, respectively. Segments 1022 may have similar length extending in the circumferential direction and similar width that are aligned to form the annular abrasive region 1002. Segments 1044 may have similar length extending in the circumferential direction and similar width that are aligned to form the annular abrasive region 1004.

[0029] In another embodiment, the body may include segments having similar or different length and / or width, substantially same or different orientations between one another, or any combination thereof, wherein segments within a same abrasive region may be arranged such that the abrasive region may have a substantially annular shape.

[0030] It is to be appreciated that for an abrasive region including abrasive segments the total volume (or weight) of the abrasive segments may be the volume (or weight) of the abrasive region. Embodiments relate to a content of a component in an abrasive region may be applied to an abrasive region including abrasive segments as an average content of the component for all segments of that abrasive region. For example, a vol% of abrasive particles in an abrasive region may be the percentage of the volume of abrasive particles in the abrasive region relative to the volume of the abrasive region. For an abrasive region including segments, the vol% of abrasive particles may be the total content of abrasive particles for the total volume of the segments within the abrasive region and also the average vol% for all segments within the abrasive region. In a particular embodiment, segments of a same abrasive region may be similar or essentially the same. In another embodiment, segments within a same or different abrasive region may be different in the content of abrasive particles and / or bond material, average abrasive particles sizes, materials of abrasive particles and / or bond material, porosity, or any combination thereof. In an embodiment, the plurality of abrasive regions may include a bond material, and abrasive particles contained in the bond material. An exemplary bond material may include an organic material, such as a thermoset, a thermoplastic, or any combination thereof. In another embodiment, one or more or all of the abrasive regions may include an organic bond material. In a further embodiment, the abrasive regions may include a same or different bond material. In a particular example, the abrasive regions may include the same bond material.

[0031] In an embodiment, one or more or all of the plurality of abrasive regions may include a particular content of the bond material that may facilitate improved performance and / or formation of the abrasive article. For example, each abrasive region may independently include at least 40 vol% of the bond material for the volume of the abrasive region, such as at least 42 vol%, at least 45 vol%, at least 48 vol%, at least 50 vol%, at least 53 vol%, at least 55 vol%, at least 58 vol%, at least 61 vol%, at least 64 vol%, at least 68 vol%, at least 70 vol%, at least 73 vol%, at least 75 vol%, at least 77 vol%, or at least 80 vol of the bond material for the volume of the abrasive region. In another example, each abrasive region may independently include at most 98 vol% of the bond material for the volume of the abrasive region, such as at most 95 vol%, at most 92 vol%, at most 90 vol%, at most 85 vol%, at most 82 vol%, at most 78 vol%, at most 75 vol%, at most 72 vol%, at most 68 vol%, at most 64 vol%, at most 60 vol%, at most 57 vol%, at most 55 vol%, at most 52 vol%, at most 50 vol%, at most 47 vol%, or at most 45 vol% of the bond material for the volume of the abrasive region. Moreover, each abrasive region may independently include a content of the bond material in a range including any of the minimum and maximum percentages noted herein. In a further embodiment, any content of the bond material in an abrasive region noted in embodiments herein may be understood as an average content of the bond material for the abrasive portion.

[0032] In an embodiment, one or more or all of the abrasive regions may include fdler. Examples of fdler may include powders, granules, spheres, fibers, hollow particles, or any combination thereof. Another example of filler may include an antistatic agent, a pore former, a lubricant, coloring agent, or any combination thereof. In a further example, filler may include a material including sand, bubble alumina, chromites, magnetite, dolomites, bubble mullite, borides, titanium dioxide, carbon products, silicon carbide, wood flour, clay, talc, hexagonal boron nitride, molybdenum disulfide, feldspar, nepheline syenite, glass spheres, glass fibers, CaF2, KBF4, Cryolite (NasAlFe), potassium Cryolite (K3AIF6), pyrite, ZnS, copper sulfide, mineral oil, fluorides, carbonates, calcium carbonate, saran, phenoxy resin, CaO, K2SO4, mineral wool, MnCh, KC1, or any combination thereof. In a particular embodiment, one or more or all of the abrasive regions may include a fdler material including lime, graphite, SiC, AI2O3, copper, or any combination thereof. In a further embodiment, abrasive regions may include the same or different fdler materials.

[0033] In a further embodiment, one or more or all of the abrasive regions may include a particular content of fdler that may facilitate improved performance and / or formation of the abrasive article. For example, one or more or all abrasive regions may independently include at least 0.5 vol% of fdler for the volume of the respective abrasive region, such as at least 1 vol%, at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, at least 20 vol%, at least 25 vol%, at least 27 vol%, at least 30 vol%, at least 34 vol%, at least 38 vol%, or at least 40 vol% of fdler for the volume of the respective abrasive region. In another example, one or more or all abrasive regions may independently include at most 40 vol% of fdler for the volume of the respective abrasive region, such as at most 38 vol%, at most 35 vol%, at most 32 vol%, at most 30 vol%, at most 27 vol%, at most 24 vol%, at most 22 vol%, at most 20 vol%, at most 17 vol%, at most 15 vol%, at most 13 vol%, at most 11 vol%, at most 9 vol%, at most 7 vol%, at most 5 vol%, at most 3 vol%, or at most 2 vol% of fdler for the volume of the respective abrasive region. Moreover, one or more or all abrasive regions may independently include a content of fdler in a range including any of the minimum and maximum percentages noted herein. In a further embodiment, any content of fdler in an abrasive region noted in embodiments herein may be understood as an average content of fdler for the abrasive portion.

[0034] In an embodiment, one or more or all of the abrasive regions may include certain porosity that may facilitate improved performance and / or formation of the abrasive article. For example, one or more abrasive regions may independently include at least 0.5 vol% of porosity for the volume of the respective abrasive region, such as at least 1 vol%, at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, or at least 20 vol% of porosity for the volume of the respective abrasive region. In another example, one or more or all abrasive regions may independently include at most 20 vol% of porosity for the volume of the respective abrasive region, such as at most 17 vol%, at most 15 vol%, at most 13 vol%, at most 11 vol%, at most 9 vol%, at most 7 vol%, at most 5 vol%, at most 3 vol%, at most 2 vol%, at most 1 vol%, or at most 0.5 vol% of porosity for the volume of the respective abrasive region. In a particular example, one or more or all abrasive regions may be essentially free of porosity. Moreover, one or more or all abrasive regions may independently include porosity in a range including any of the minimum and maximum percentages noted herein. In a further embodiment, any porosity in an abrasive region noted in embodiments herein may be understood as an average porosity for the abrasive portion.

[0035] In an embodiment, the plurality of abrasive regions may include a particular content of abrasive particles that may facilitate improved performance and / or formation of the abrasive article. For example, each abrasive region may independently include at least 1 vol% of abrasive particles for the volume of the abrasive region, such as at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, at least 20 vol%, at least 25 vol%, at least 27 vol%, at least 30 vol%, at least 34 vol%, at least 38 vol%, at least 40 vol%, at least 42 vol%, at least 45 vol%, at least 48 vol%, at least 50 vol%, at least 53 vol%, or at least 55 vol% of abrasive particles for the volume of the abrasive region. In another example, each abrasive region may independently include at most 60 vol% of abrasive particles for the volume of the abrasive region, such as at most 57 vol%, at most 55 vol%, at most 52 vol%, at most 50 vol%, at most 47 vol%, at most 45 vol%, at most 43 vol%, at most 40 vol%, at most 38 vol%, at most 35 vol%, at most 32 vol%, at most 30 vol%, at most 27 vol%, at most 24 vol%, at most 22 vol%, at most 20 vol%, at most 17 vol%, at most 15 vol%, at most 13 vol%, or at most 11 vol% of abrasive particles for the volume of the abrasive region. Moreover, each abrasive region may independently include a content of abrasive particles in a range including any of the minimum and maximum percentages noted herein. In a further embodiment, any content of abrasive particles in an abrasive region noted in embodiments herein may be understood as an average content of abrasive particles for the abrasive portion.

[0036] In a further embodiment, the plurality of abrasive regions may include different contents of abrasive particles between one another. In an example, at least two abrasive regions may include different contents of abrasive particles, wherein the differences may be within ±15%, within ±12%, within ±8%, or within ±5% of the bigger content of the at least two abrasive regions. In another embodiment, at least some or all of the plurality of abrasive regions may include essentially a same content of abrasive particles.

[0037] In an embodiment, each abrasive region may include abrasive particles. Abrasive particles may have certain hardness that may be higher than hardness of fdler. For instance, the abrasive particles may have Mohs hardness of at least 7, such as at least 7.5, at least about 8, at least about 8.5, or even at least about 9. Abrasive particles may include an inorganic material including a naturally occurring material, a synthesized material, or a combination thereof. Some exemplary abrasive particles may include materials such as oxides, carbides, nitrides, borides, oxycarbides, oxynitrides, oxyborides, carbon-containing materials, diamond, or any combination thereof.

[0038] In an embodiment, one or more or all of the abrasive regions may include abrasive particles including a superabrasive material, an oxide, a carbide, a nitride, or any combination thereof. A particular example of abrasive particles may include diamond, cubic boron nitride (cBN), alumina oxide (AI2O3), silicon carbide (SiC), cerium oxide (CcCh), or any combination thereof. In a particular embodiment, the abrasive particles may include a superabrasive material including diamond, cBN, or a combination thereof. In a more particular example, a majority (i.e., greater than 50 vol%) of the abrasive particles may include a superabrasive material; or even more particularly, essentially all of the abrasive particles may include a superabrasive material. In another particular embodiment, one or more or all of the abrasive regions may include abrasive particles that may consist essentially of a superabrasive material. For example, the abrasive particles of one or more or all of the abrasive regions may consist of diamond, cBN, or any combination thereof. The abrasive particles may include a superabrasive material, and more particularly, may consist essentially of a superabrasive material. For at least one embodiment, the abrasive particles of each of the abrasive regions may include diamond. In still other instances, one or more of the abrasive regions may include abrasive particles including cBN. In at least one non-limiting embodiment, the abrasive particles may consist essentially of diamond. In still another embodiment, one or more or all of the abrasive regions may include a blend of abrasive particles including a superabrasive material. In an example, one or more or all of the abrasive regions may include secondary abrasive particles. Exemplary secondary particles may include AI2O3, SiC, flint, garnet grains, ceramic corundum, flint, cerium oxide, or any combination thereof.

[0039] In an embodiment, the body may include a first abrasive region including a first diameter and a second abrasive region including a second diameter smaller than the first diameter. For example, the first abrasive region may be an outer abrasive region, and the second abrasive region may be an inner abrasive region closer to the center of the body compared to the first region.

[0040] In another embodiment, the first abrasive region may include abrasive particles having a particular first average particle size that may facilitate improved performance of the abrasive article. In an embodiment, the first average particle size may be at least 1 microns, such as at least 3 microns, at least 5 microns, at least 8 microns, at least 10 microns, at least 13 microns, at least 15 microns, at least 17 microns, at least 19 microns, at least 20 microns, at least 23 microns, at least 25 microns, at least 28 microns, at least 32 microns, at least 35 microns, at least 37 microns, at least 40 microns, at least 43 microns, or at least 45 microns. Additionally or alternatively, the first average particle size may be at most 150 microns, at most 130 microns, at most 100 microns, at most 95 microns, at most 90 microns, at most 85 microns, at most 80 microns, at most 75 microns, at most 70 microns, at most 65 microns, at most 60 microns, at most 55 microns, at most 50 microns, at most 45 microns, at most 40 microns, at most 35 microns, at most 30 microns, at most 27 microns, at most 25 microns, at most 22 microns, or at most 20 microns. Moreover, the first average particle size may be within a range including any of the minimum and maximum values noted herein. For example, the first average particle size may be within a range from 1 micron to 100 microns, within a range from 5 microns to 85 microns, within a range from 8 microns to 65 microns, or within a range from 10 microns to 20 microns.

[0041] In another embodiment, the second abrasive region may include abrasive particles having a second average particle size that may facilitate improved performance of the abrasive article. In a particular embodiment, the second average particle size may be greater than the first average particle size.

[0042] In a further embodiment, the second average particle size may be at least 10 microns, such as at least 13 microns, at least 15 microns, at least 17 microns, at least 19 microns, at least 20 microns, at least 25 microns, at least 30 microns, at least 35 microns, at least 40 microns, at least 40 microns, at least 45 microns, at least 50 microns, at least 55 microns, at least 60 microns, at least 65 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 110 microns, at least 130 microns, at least 150 microns, at least 180 microns, at least 200 microns, at least 250 microns, at least 300 microns, at least 350 microns, or at least 400 microns. Additionally or alternatively, the second average particle size may be at most 500 microns, at most 450 microns, at most 400 microns, at most 350 microns, at most 300 microns, at most 250 microns, at most 200 microns, at most 150 microns, at most 100 microns, at most 90 microns, at most 85 microns, at most 80 microns, at most 75 microns, at most 70 microns, at most 65 microns, at most 60 microns, at most 55 microns, at most 50 microns, at most 45 microns, at most 40 microns, at most 35 microns, at most 30 microns, at most 27 microns, at most 25 microns, at most 22 microns, or at most 20 microns. Moreover, the second average particle size may be within a range including any of the minimum and maximum values noted herein. For example, the second average particle size may be within a range from 10 microns to 500 microns, within a range from 15 microns to 400 microns, within a range from 20 microns to 300 microns, or within a range from 30 microns to 200 microns.

[0043] In a particular embodiment, the body may include a particular particle size ratio, Rpss / f, of the second average particle size to the first average particle size that may facilitate improved performance of the abrasive article. In an example, the particle size ratio, Rpss / f, may be at least 1.1 : 1, such as at least 1.3: 1, at least 1.5: 1, at least 1.7: 1, at least 1.9: 1, at least 2.2: 1, at least 2.5: 1, at least 2.8: 1, at least 3.1 : 1, or at least 3.5: 1. In another example, the particle size ratio, Rpss / f, may be at most 5.0: 1, such as at most 4.8: 1, at most 4.6: 1, at most 4.4: 1, at most 4.2: 1, at most 4.0: 1, at most 3.8: 1, at most 3.6: 1, at most 3.5: 1, at most 3.3: 1, at most 3.1 : 1, at most 2.8: 1, at most 2.6: 1, at most 2.4: 1, at most 2.2: 1, at most 1.8: 1, or at most 1.5: 1. Moreover, the particle size ratio, Rpss / f, may be within a range including any of the minimum and maximum values noted herein. For example, the particle size ratio, Rpss / f, may be within a range from 1.1 to 5.0: 1 or within a range from 1.3 to 3.6: 1.

[0044] In a further embodiment, the body may include a ratio, CAPRI / CAPR2, of abrasive particle contents between the first abrasive region and the second abrasive region that may facilitate improved formation and / or performance of abrasive article, wherein the first abrasive region may include a first abrasive particle content, CAPRI, for the volume of the first abrasive region, and the second abrasive region may include a second abrasive particle content, CAPR2, for the volume of the second abrasive region. In an example, the ratio, CAPRI / CAPR2, may be at least 0.1, at least 0.4, at least 0.6, at least 0.8, at least 1.0, at least 1.2, at least 1.5, at least 1.8, at least 2.0, at least 2.4, at least 2.7, at least 3.0, at least 3.2, at least

[0045] 3.5, at least 3.8, at least 4, at least 4.2, at least 4.5, at least 4.8, at least 5.0, at least 5.3, at least

[0046] 5.6, at least 6.0, at least 6.5, at least 6.8, at least 7, or at least 7.2. In another example, the ratio, CAPRI / CAPR2, may be at most 10, at most 9.5, at most 9, at most 8.7, at most 8.5, at most 8, at most 7.5, at most 7.2, at most 7.0, at most 6.8, at most 6.6, at most 6.2, at most 6, at most

[0047] 5.7, at most 5.4, at most 5.2, at most 5.0, at most 4.8, at most 4.5, at most 4.2, at most 4.0, at most 3.8, at most 3.6, at most 3.2, at most 3, at most 2.8, at most 2.5, at most 2.2, at most 2.0, at most 1.8, at most 1.6, at most 1.4, at most 1.2, or at most 1.0. Moreover, the ratio, CAPRI / CAPR2, may be in a range including any of the minimum and maximum values noted herein.

[0048] In an embodiment, the body may include a third concentric abrasive region that may be positioned closer to the central opening than the second abrasive region, which may facilitate improved formation and / or performance of the abrasive article. For example, the third abrasive region may have a smaller outer diameter than the second abrasive region. In another embodiment, the third abrasive region may include abrasive particles having a third average particle size, wherein the third average particle size may be smaller than the second abrasive particle size. In another embodiment, the third average particle size may be essentially the same as, greater, or smaller than the first average abrasive particle size. For example, the third average particle size may include any average particle sizes described with respect to the first average particle size in embodiments herein.

[0049] FIGs. 1 and 2 include a top-down and cross-sectional illustration of an exemplary abrasive article 100, respectively, according to an embodiment. The abrasive article 100 may include a body 101 including a substrate 102 and a plurality of annular concentric abrasive regions 103 to 105 disposed on a surface of the substrate 102. The substrate 102 or the body 101 may include a central opening 150 and the abrasive regions 103 to 105 may be concentric with the central opening 150. In the illustrated example, the body 101 includes a first abrasive region 103 having an outer diameter DI, a second abrasive region 104 having an outer diameter D2, and a third abrasive region 105 including an outer diameter D3, wherein D1>D2>D3. The total surface areas of the first, second and third abrasive regions may make up the surface area of the abrasive portion of the body 101. The outer dimeter DI may be the outer diameter of the body lOldefining an outer circumference of the body 101. The body 101 may include an inner diameter Di that may be the inner diameter of the innermost (i.e., third) abrasive region 105.

[0050] The first abrasive region 103, the second abrasive region 104, and the third abrasive region 105 may be spaced apart from one another by a non-abrasive portion. In a particular embodiment, the non-abrasive portion may be essentially free of abrasive particles, bond material, filler, or any combination thereof. In a more particular embodiment, the non- abrasive portion may consist of a portion of the substrate.

[0051] As illustrated in FIGs. 1 and 2, the body 101 may include annular non-abrasive portions 113 and 115, wherein the non-abrasive portion 113 may be positioned between the first 103 and second 104 abrasive regions, and the non-abrasive portions 115 may be positioned between the second 104 and the third 105 abrasive regions.

[0052] In a particular embodiment, the body may include a particular particle size ratio, Rpss / t, of the second average particle size to the third average particle size that may facilitate improved performance of the abrasive article. In an example, the particle size ratio, Rpss / t, may be at least 1.1 : 1, such as at least 1.3: 1, at least 1.5: 1, at least 1.7: 1, at least 1.9: 1, at least 2.2: 1, at least 2.5: 1, at least 2.8: 1, at least 3.1 : 1, or at least 3.5: 1. In another example, the particle size ratio, Rpss / t, may be at most 5.0: 1, such as at most 4.8: 1, at most 4.6: 1, at most 4.4: 1, at most 4.2: 1, at most 4.0: 1, at most 3.8: 1, at most 3.6: 1, at most 3.5: 1, at most 3.3: 1, at most 3.1 : 1, at most 2.8: 1, at most 2.6: 1, at most 2.4: 1, at most 2.2: 1, at most 1.8: 1, or at most 1.5: 1. Moreover, the particle size ratio, Rpss / t, may be within a range including any of the minimum and maximum values noted herein. For example, the particle size ratio, Rpss / t, may be within a range from 1.1 to 5.0: 1 or within a range from 1.3 to 3.6: 1.

[0053] In a further embodiment, the body may include a ratio, CAPR3 / CAPR2, of abrasive particle contents between the third abrasive region and the second abrasive region that may facilitate improved formation and / or performance of abrasive article, wherein the third abrasive region may include a third abrasive particle content, CAPRS, for the volume of the third abrasive region. In an example, the ratio, CAPR3 / CAPR2, may be at least 0.1, at least 0.4, at least 0.6, at least 0.8, at least 1.0, at least 1.2, at least 1.5, at least 1.8, at least 2.0, at least

[0054] 2.4, at least 2.7, at least 3.0, at least 3.2, at least 3.5, at least 3.8, at least 4, at least 4.2, at least

[0055] 4.5, at least 4.8, at least 5.0, at least 5.3, at least 5.6, at least 6.0, at least 6.5, at least 6.8, at least 7, or at least 7.2. In another example, the ratio, CAPR3 / CAPR2, may be at most 10, at most

[0056] 9.5, at most 9, at most 8.7, at most 8.5, at most 8, at most 7.5, at most 7.2, at most 7.0, at most 6.8, at most 6.6, at most 6.2, at most 6, at most 5.7, at most 5.4, at most 5.2, at most 5.0, at most 4.8, at most 4.5, at most 4.2, at most 4.0, at most 3.8, at most 3.6, at most 3.2, at most 3, at most 2.8, at most 2.5, at most 2.2, at most 2.0, at most 1.8, at most 1.6, at most 1.4, at most 1.2, or at most 1.0. Moreover, the ratio CAPR3 / CAPR2, may be in a range including any of the minimum and maximum values noted herein.

[0057] In a further embodiment, the body may include a ratio, CAPRS / CAPRI, of the third abrasive content and the first abrasive content that may facilitate improved formation and / or performance of abrasive article. In an example, the ratio, CAPRS / CAPRI, may be at least 0.1, at least 0.4, at least 0.6, at least 0.8, at least 1.0, at least 1.2, at least 1.5, at least 1.8, at least 2.0, at least 2.4, at least 2.7, at least 3.0, at least 3.2, at least 3.5, at least 3.8, at least 4, at least 4.2, at least 4.5, at least 4.8, at least 5.0, at least 5.3, at least 5.6, at least 6.0, at least 6.5, at least 6.8, at least 7, or at least 7.2. In another example, the ratio, CAPRS / CAPRI, may be at most 10, at most 9.5, at most 9, at most 8.7, at most 8.5, at most 8, at most 7.5, at most 7.2, at most 7.0, at most 6.8, at most 6.6, at most 6.2, at most 6, at most 5.7, at most 5.4, at most 5.2, at most 5.0, at most 4.8, at most 4.5, at most 4.2, at most 4.0, at most 3.8, at most 3.6, at most 3.2, at most 3, at most 2.8, at most 2.5, at most 2.2, at most 2.0, at most 1.8, at most 1.6, at most 1.4, at most 1.2, or at most 1.0. Moreover, the ratio, CAPRS / CAPRI, may be in a range including any of the minimum and maximum values noted herein. In a further embodiment, at least two of the first, second, and third abrasive particle contents may be essentially the same or different. In a particular example, the first, second, and third abrasive particle contents may be essentially same. In another embodiment, a difference between the at least two of the first, second, and third abrasive particle contents may be within ±15%, within ±12%, within ±8%, or within ±5% of bigger of the at least two abrasive particle contents.

[0058] In a further embodiment, the body may include an outermost abrasive region. For example, the outermost abrasive region may include an outer circumference that may define the outer circumference of the body. For example, the first abrasive region 103 illustrated in FIG. 1 is the outermost abrasive region of the body 101. In another example, the outer circumference of the outermost abrasive region may be substantially aligned with and / or the same as the outer circumference of the substrate. In still another example, the outer diameter of the outermost abrasive region may define the outer diameter of the body. In another embodiment, the outermost abrasive region may include one or more abrasive portions. In an example, the outermost abrasive region may include a plurality of abrasive portions that may be spaced apart from one another by a non-abrasive portion. In a particular example, the plurality of abrasive portions may be concentric, wherein each abrasive portion may have a substantially annular shape. In another example, the outermost abrasive region may include at least 1 abrasive portion or at least 2 concentric abrasive portions, such as 3, 4, 5 or more concentric abrasive portions.

[0059] In a further embodiment, the outermost abrasive region may include abrasive portions having similar or different characteristics including one or more of the abrasive surface area, radial thickness, the content of abrasive particles, average abrasive particle sizes, the content of the bond material, porosity, the content of filler, materials of abrasive particles, bond, and / or filler, or any combination thereof. For example, the abrasive portions may include similar or different average abrasive particle sizes. In another embodiment, the outermost abrasive region may include one or more non-abrasive portions. In an example, non-abrasive portions within the outermost abrasive region may have substantially the same or different radial thickness.

[0060] In another embodiment, the outermost abrasive region may include an average abrasive particles size for all the abrasive portions within the outermost abrasive region, wherein the average abrasive particle size may be smaller than next inner abrasive region. In a particular example, the average particle size of the outermost abrasive region may include any values described with respect to the first average abrasive size. The average particle size could be determined by using Laser diffraction according to ISO 13320:2020.

[0061] In a further embodiment, the body may include an innermost abrasive region. The innermost abrasive region may be spaced apart from the central opening by a radial distance. In an example, the radial distance may be suited for mounting and / or operating the abrasive article on certain grinding machines. In another embodiment, the innermost abrasive region may include one or more abrasive portions. In an example, the innermost abrasive region may include a plurality of abrasive portions that may be spaced apart from one another by a non-abrasive portion. In a particular example, the plurality of abrasive portions may be concentric, wherein each abrasive portion may have a substantially annular shape. In another example, the innermost abrasive region may include at least 1 abrasive portion or at least 2 concentric abrasive portions, such as 3, 4, 5 or more concentric abrasive portions.

[0062] In another embodiment, the innermost abrasive region may include abrasive portions having similar or different characteristics including one or more of the abrasive surface area, radial thickness, the content of abrasive particles, average abrasive particle sizes, the content of the bond material, porosity, the content of filler, materials of abrasive particles, bond, and / or filler, or any combination thereof. For example, the abrasive portions may include similar or different average abrasive particle sizes. In another embodiment, the innermost abrasive region may include one or more non-abrasive portions. In an example, non-abrasive portions within the innermost abrasive region may have substantially the same or different radial thickness.

[0063] In another embodiment, the innermost abrasive region may include an average abrasive particles size for all the abrasive portions within the innermost abrasive region, wherein the average abrasive particle size may be smaller than next outer abrasive region. In an example, the innermost abrasive region may include an average particle size including any values described with respect to the first average abrasive size. In a particular example, the third abrasive region may be the innermost abrasive region.

[0064] In a further embodiment, the body may include the first abrasive region as the outermost abrasive region, the third abrasive region as the innermost abrasive region, and the second abrasive region as the middle abrasive region between the innermost and outermost abrasive regions. In an embodiment, the body may include a middle abrasive region including one or more abrasive portions. In an example, the middle abrasive region may include a plurality of abrasive portions that may be spaced apart from one another by a non- abrasive portion. In a particular example, the plurality of abrasive portions may be concentric, wherein each abrasive portion may have a substantially annular shape. In another example, the middle abrasive region may include at least 1 abrasive portion or at least 2 concentric abrasive portions, such as 3, 4, 5 or more concentric abrasive portions.

[0065] In another embodiment, the middle abrasive region may include abrasive portions having similar or different characteristics including one or more of the abrasive surface area, radial thickness, the content of abrasive particles, average abrasive particle sizes, the content of the bond material, porosity, the content of filler, materials of abrasive particles, bond, and / or filler, or any combination thereof. For example, the abrasive portions may include similar or different average abrasive particle sizes. In another embodiment, the middle abrasive region may include one or more non-abrasive portions. In an example, non-abrasive portions within the middle abrasive region may have substantially the same or different radial thickness.

[0066] In another embodiment, the middle abrasive region may include an average abrasive particles size for all the abrasive portions within the middle abrasive region, wherein the average abrasive particle size may be greater than next outer abrasive region (i.e., the outermost abrasive region) and greater than next inner abrasive region (i.e., the innermost abrasive region). In an example, the middle abrasive region may include an average particle size including any values described with respect to the second average abrasive size.

[0067] Referring to FIG. 8, a representative abrasive article 800 is illustrated including a body 801 including abrasive regions 802, 803, and 804. The abrasive region 802 is the outermost abrasive region including concentric annular abrasive portions 812 and 822 and a non-abrasive portion 852 between the abrasive portions 812 and 822. The abrasive portions 812 and 822 include segments 832. In another example, one or each of the abrasive portions 812 and 822 may not be segmented.

[0068] The middle abrasive region 803 includes concentric annular abrasive portions 813 and

[0069] 823 that are spaced part by a non-abrasive portion. The abrasive portions 813 and 823 include segments 833. In another example, one or each of the abrasive portions 813 and 823 may not be segmented.

[0070] The inner abrasive region 804 includes concentric annular abrasive portions 814 and

[0071] 824 that are spaced part by a non-abrasive portion. The abrasive portions 814 and 824 include segments 834. In another example, one or each of the abrasive portions 814 and 824 may not be segmented.

[0072] In an embodiment, the body may include a particular percentage of the surface area of the abrasive regions that may facilitate improved performance and / or formation of the abrasive article. As used herein, the surface area of an abrasive region is intended to refer to the total work surface area of the abrasive region. The work surface of an abrasive region is the surface that is intended for contacting a workpiece, such as the top surface of each abrasive region as viewed in the cross-sectional illustration of the abrasive article 100 in FIG. 2. In an embodiment, the body may include a percent surface area of the abrasive regions of at least 15%, such as at least 18%, at least 20%, at least 22%, at least 25%, at least 28%, at least 30%, at least 32%, at least 35%, at least 38%, at least 41%, at least 45%, at least 48%, at least 50%, at least 52%, at least 55%, at least 58%, at least 60%, at least 63%, at least 65%, or at least 68%. Alternatively or additionally, the percent surface area of the abrasive regions may be at most 76%, such as at most 73%, at most 70%, at most 68%, at most 65%, at most 63%, at most 60%, at most 58%, at most 55%, at most 53%, at most 50%, at most 48%, at most 45%, at most 43%, at most 40%, at most 38%, at most 35%, at most 33%, at most 30%, at most 28%, or at most 25%. Moreover, the body may include a percent surface area of the abrasive regions in a range including any of the minimum and maximum percentages noted herein. For example, the percent surface area of the abrasive regions may be in a range including at least 15% and at most 75% or in a range including at least 22% and at most 72% or in a range including at least 30% and at most 70%. The percent surface area of the abrasive regions may be the percentage of the surface area of all the abrasive regions relative to the surface area of the body 101 between the inner circumference of the innermost abrasive region (i.e., defined by the inner diameter Di) and the outermost circumference (i.e., defined by the diameter DI) of the body 101 illustrated in FIG. 1.

[0073] In a further embodiment, the first abrasive region (i.e., the outermost abrasive region) may include a particular first percent abrasive surface area relative to the surface area of the abrasive regions that may facilitate improved performance of the abrasive article 100. For example, the first percent abrasive surface area may be at least 10% relative to the surface area of the abrasive regions, such as at least 13%, at least 15%, at least 18%, at least 20%, at least 22%, at least 25%, at least 28%, at least 30%, at least 33%, at least 35%, at least 37%, at least 40%, at least 43%, at least 45%, at least 50%, at least 55%, at least 60%%, at least 64%, at least 68%, at least 70%, or at least 75% relative to the surface area of the abrasive regions. In another example, the first percent abrasive surface area may be at most 80% relative to the surface area of the abrasive regions, such as at most 75%, at most 70%, at most 65%, at most 60%, at most 56%, at most 52%, at most 48%, at most 45%, at most 43%, at most 40%, at most 38%, at most 35%, at most 33%, at most 30%, at most 27%, at most 25%, at most 23%, or at most 20% relative to the surface area of the abrasive regions. Moreover, the first percent abrasive surface area may be in the range including any of the minimum and maximum percentages noted herein. For example, the first percent abrasive surface area may be in the range from 10% to 80% or in the range from 10% to 50% or in a range from 20% to 45 % relative to the surface area of the abrasive regions.

[0074] In a further embodiment, the third abrasive region (i.e., the innermost abrasive region) may include a third percent abrasive surface area for the surface area of the abrasive regions that may facilitate improved performance of the abrasive article. For example, the third abrasive surface area may be at least 10% relative to the surface area of the abrasive regions, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%%, at least 64%, at least 68%, at least 70%, or at least 75% relative to the surface area of the abrasive regions. In another example, the third percent abrasive surface area may be at most 80% relative to the surface area of the abrasive regions, such as at most 75%, at most 70%, at most 65%, at most 60%, at most 56%, at most 52%, at most 48%, at most 45%, at most 42%, at most 40%, at most 38%, at most 35%, at most 32%, at most 30%, at most 28%, at most 25%, at most 23%, or at most 20% relative to the surface area of the abrasive regions. Moreover, the third percent abrasive surface area may be in the range including any of the minimum and maximum percentages noted herein. For example, the third percent abrasive surface area may be in the range from 10% to 80% or in the range from 10% to 50% or in a range from 20% to 45 % relative to the surface area of the abrasive regions. In a further example, the third percent abrasive surface area may be essentially the same as or different from the first percent abrasive surface area.

[0075] In a further embodiment, the second abrasive region (i.e., the middle abrasive region) may include a second percent abrasive surface area for the surface area of the abrasive regions that may facilitate improved performance of the abrasive article. For example, the second abrasive surface area may be at least 10% relative to the surface area of the abrasive regions, such as at least 12%, at least 15%, at least 20%, at least 23%, at least 25%, at least 30%, at least 33%, at least 35%, at least 38%, at least 40%, at least 42%, at least 45%, at least 50%, at least 55%, at least 60%%, at least 64%, at least 68%, at least 70%, or at least 75% relative to the surface area of the abrasive regions. In another example, the second percent abrasive surface area may be at most 80% relative to the surface area of the abrasive regions, such as at most 75%, at most 70%, at most 65%, at most 60%, at most 56%, at most 52%, at most 48%, at most 45%, at most 42%, at most 40%, at most 38%, at most 35%, at most 32%, at most 30%, at most 28%, at most 25%, at most 23%, or at most 20% relative to the surface area of the abrasive regions. Moreover, the second percent abrasive surface area may be in the range including any of the minimum and maximum percentages noted herein. For example, the second percent abrasive surface area may be in the range from 10% to 80% or in the range from 10% to 50% or in a range from 20% to 45 % relative to the surface area of the abrasive regions. In a further example, the second percent abrasive surface area may be essentially the same as or different from the first and / or the third percent abrasive surface area. In a particular embodiment, the second percent abrasive surface area may be essentially the same as the first and / or the third percent abrasive surface area. In an example, the second percent abrasive surface area may be not greater or less than the first percent abrasive surface area. In another example, the second percent abrasive surface area may be at least or greater than the third percent abrasive surface area.

[0076] In an embodiment, the body may include a particular surface area ratio of the first abrasive region to the second abrasive region RSAI / 2 that may facilitate improved performance of the abrasive article. In an example, the ratio RSAI / 2 may be at least 1 : 10, such as at least 1 :9, at least 1 :8, at least 1 :7, at least 1 :6, at least 1 :5, at least 1 :3, at least 1 : 1, at least 2: 1, at least 3: 1, at least 4: 1, at least 5: 1, at least 6: 1, at least 7: 1, at least 8: 1, at least 9: 1, or at least 10: 1. In another example, the ratio RSAI / 2 may be at most 10: 1, at most 9: 1, at most 8: 1, at most 7: 1, at most 6: 1, at most 5: 1, at most 4: 1, at most 2: 1, at most 1 : 1, at most 1 :2, at most 1 :3, at most 1 :4, at most 1 :5, at most 1 :6, at most 1 :7, at most 1 :8, at most 1 :9, or at most 1 : 10. Moreover, the ratio RSAI / 2 may be in a range including any of the minimum and maximum values noted herein. For example, the ratio RSAI / 2 may be in a range from 1 : 10 to 10: 1 or in a range from 1 :5 to 5: 1 or in a range from 1 :3 to 3: 1 or in a range from 1 :2 to 2: 1.

[0077] In an embodiment, the body may include a particular surface area ratio of the first abrasive region to the third abrasive region RSAI / 3 that may facilitate improved performance of the abrasive article. In an example, the ratio RSAI / 3 may be at least 1 : 10, such as at least 1 :9, at least 1 :8, at least 1 :7, at least 1 :6, at least 1 :5, at least 1 :3, at least 1 : 1, at least 2: 1, at least 3: 1, at least 4: 1, at least 5: 1, at least 6: 1, at least 7: 1, at least 8: 1, at least 9: 1, or at least 10: 1. In another example, the ratio RSAI / 3 may be at most 10: 1, at most 9: 1, at most 8: 1, at most 7: 1, at most 6: 1, at most 5: 1, at most 4: 1, at most 2: 1, at most 1 : 1, at most 1 :2, at most 1 :3, at most 1 :4, at most 1 :5, at most 1 :6, at most 1 :7, at most 1 :8, at most 1 :9, or at most 1 : 10. Moreover, the ratio RSAI / 3 may be in a range including any of the minimum and maximum values noted herein. For example, the ratio RSAI / 3 may be in a range from 1 : 10 to 10: 1 or in a range from 1 :5 to 5: 1 or in a range from 1 :3 to 3: 1 or in a range from 1 :2 to 2: 1.

[0078] In an embodiment, the body may include a particular surface area ratio of the second abrasive region to the third abrasive region RSA2 / 3 that may facilitate improved performance and / or formation of the abrasive article. In an example, the ratio RSA2 / 3 may be at least 1 : 10, such as at least 1 :9, at least 1 :8, at least 1 :7, at least 1 :6, at least 1 :5, at least 1 :3, at least 1 : 1, at least 2: 1, at least 3: 1, at least 4: 1, at least 5: 1, at least 6: 1, at least 7: 1, at least 8: 1, at least 9: 1, or at least 10: 1. In another example, the ratio RSAI / 3 may be at most 10: 1, at most 9: 1, at most 8: 1, at most 7: 1, at most 6: 1, at most 5: 1, at most 4: 1, at most 2: 1, at most 1 : 1, at most 1 :2, at most 1 :3, at most 1 :4, at most 1 :5, at most 1 :6, at most 1 :7, at most 1 :8, at most 1 :9, or at most 1 : 10. Moreover, the ratio RSA2 / 3 may be in a range including any of the minimum and maximum values noted herein. For example, the ratio RSAI / 3 may be in a range from 1 : 10 to 10: 1 or in a range from 1 :5 to 5: 1 or in a range from 1 :3 to 3: 1 or in a range from 1 :2 to 2: 1.

[0079] In an embodiment, the first abrasive region (e.g., the abrasive region 103 illustrated in FIG. 1) may include a particular first radial thickness tl (illustrated in FIG. 2) that may facilitate improved performance and / or formation of the abrasive article. In a further embodiment, the first radial thickness tl may be at least 0.3% relative to the outer dimeter DI of the body, such as at least 0.5%, at least 0.7%, at least 1%, at least 1.2%, at least 1.5%, at least 2%, at least 3%, at least 5%, at least 7%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 22%, at least 25%, at least 28%, at least 30%, at least 33%, or at least 35% relative to the outer dimeter DI of the body. Alternatively or additionally, the first radial thickness tl may be at most 40% relative to an outer dimeter of the body, at most 35%, at most 33%, at most 30%, at most 27%, at most 25%, at most 22%, at most 20%, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, at most 5%, at most 3.8%, at most 3.5%, at most 3%, or at most 2% relative to the outer dimeter of the body. Moreover, the first radial thickness tl may be in a range including any of the minimum and maximum percentages noted herein. For example, tl may be in a range from 0.3% to 40% of the outer diameter DI or in a range from 0.5% to 35% or in a range from 1% to 25% or in a range from 1% to 15% or in a range from 2% to 7% of the outer diameter DI . In a further embodiment, for the outermost abrasive region including a plurality of abrasive portions, tl may be the total radial thickness of the abrasive portions.

[0080] In a further embodiment, the second abrasive region (e.g., the abrasive region 104 illustrated in FIG. 1) may include a particular second radial thickness t2 (illustrated in FIG. 2) that may facilitate improved performance and / or formation of the abrasive article. For example, the second radial thickness t2 may be at least 0.1% relative to the outer dimeter DI of the body, such as at least 0.3%, at least 0.5%, at least 0.8%, at least 1%, at least 1.2%, at least 1.7%, at least 2%, at least 3%, at least 5%, at least 7%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 22%, at least 25%, at least 28%, at least 30%, at least 33%, or at least 35% relative to the outer dimeter DI of the body. In another example, the second radial thickness t2 may be at most 40% relative to an outer dimeter of the body, at most 35%, at most 33%, at most 30%, at most 27%, at most 25%, at most 22%, at most 20%, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, at most 5%, at most 3%, at most 2.6%, at most 2%, or at most 1% relative to the outer dimeter of the body. Moreover, the second radial thickness t2 may be in a range including any of the minimum and maximum percentages noted herein. For example, t2 may be in a range from 1% to 40% of the outer diameter DI or in a range from 1% to 35% or in a range from 1% to 25% or in a range from 1% to 15% or in a range from 2% to 7% of the outer diameter DI . In a further embodiment, for the middle abrasive region including a plurality of abrasive portions, t2 may be the total radial thickness of the abrasive portions.

[0081] In a further embodiment, the third abrasive region (e.g., the abrasive region 105 illustrated in FIG. 1) may include a particular third radial thickness t3 (illustrated in FIG. 2) that may facilitate improved performance and / or formation of the abrasive article. For example, the third radial thickness t3 may be at least 0.1% relative to the outer dimeter DI of the body, such as at least 0.3%, at least 0.5%, at least 0.8%, at least 1%, at least 1.2%, at least 1.7%, at least 2%, at least 3%, at least 5%, at least 7%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 22%, at least 25%, at least 28%, at least 30%, at least 33%, or at least 35% relative to the outer dimeter DI of the body. In another example, the third radial thickness t3 may be at most 40% relative to an outer dimeter of the body, at most 35%, at most 33%, at most 30%, at most 27%, at most 25%, at most 22%, at most 20%, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, at most 5%, at most 3%, at most 2.6%, at most 2%, or at most 1% relative to the outer dimeter of the body. Moreover, the third radial thickness t3 may be in a range including any of the minimum and maximum percentages noted herein. For example, t3 may be in a range from 1% to 40% of the outer diameter DI or in a range from 1% to 35% or in a range from 1% to 25% or in a range from 1% to 15% or in a range from 2% to 7% of the outer diameter DI. In a further embodiment, the first radial thickness tl may be essentially the same as the second radial thickness t2 and / or the third radial thickness t3. For example, the radial thickness tl, t2, and t3 may be essentially the same. In a further embodiment, for the innermost abrasive region including a plurality of abrasive portions, t3 may be the total radial thickness of the abrasive portions.

[0082] In an embodiment, the body (e.g., 101 illustrated in FIGs.1-2) may include an axial height Hb, and the first, second, and third abrasive regions (e.g., 103 to 105 illustrated in FIGs.1-2) may include an axial height Hari, Har2, and Har3, respectively (illustrated in FIG. 2). In a further embodiment, for an abrasive region (e.g., the third / innermost, second / middle, and / or first / outermost abrasive region) including a plurality of abrasive portions, the axial height of the abrasive region may be the average axial height for the abrasive portions within the abrasive region. In a further embodiment, the first abrasive region may include a particular first axial height Hari that may facilitate improved performance and / or formation of the abrasive article. For example, the first axial height Harimay be at least 1% relative to the axial height Hb of the body 101, such as at least 2%, at least 4%, at least 6%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 33%, at least 35%, at least 38%, at least 40%, at least 42%, at least 45%, at least 47%, or at least 50% relative to the axial height Hb of the body. In another example, the first axial height Hari may be at most 50% relative to the axial height Hb of the body, such as at most 47%, at most 44%, at most 41%, at most 38%, at most 35%, at most 33%, at most 30%, at most 27%, at most 25%, at most 22%, at most 20%, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, at most 5%, at most 3%, or at most 2% relative to the axial height Hb of the body 101. Moreover, the first axial height Harimay be in a range including any of the minimum and maximum percentages noted herein. For example, the first axial height Harimay be in a range from 1% to 50% or in a range from 2% to 30% or in a range from 4% to 24%.

[0083] In a further embodiment, the second abrasive region may include a particular second axial height Har2 that may facilitate improved performance and / or formation of the abrasive article. For example, the second axial height Hai-2 may be at least 1% relative to the axial height Hb of the body 101, such as at least 2%, at least 4%, at least 6%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 22%, at least 25%, at least 28%, at least 30%, at least 33%, at least 35%, at least 38%, at least 40%, at least 42%, at least 45%, at least 47%, or at least 50% relative to the axial height Hb of the body. In another example, the second axial height Hai-2 may be at most 50% relative to the axial height Hb of the body 101, such as at most 47%, at most 44%, at most 41%, at most 38%, at most 35%, at most 33%, at most 30%, at most 27%, at least 24%, at least 26%, at most 22%, at most 20%, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, at most 5%, at most 3%, or at most 2% relative to the axial height Hb of the body. Moreover, the second axial height Har2 may be in a range including any of the minimum and maximum percentages noted herein. For example, the second axial height Har2 may be in a range from 1% to 50% or in a range from 2% to 30% or in a range from 4% to 24%. In a further embodiment, the third abrasive region may include a particular third axial height Har3 that may facilitate improved performance and / or formation of the abrasive article. For example, the third axial height Har3 may be at least 1% relative to the axial height Hb of the body, such as at least 2%, at least 4%, at least 6%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 33%, at least 35%, at least 38%, at least 40%, at least 42%, at least 45%, at least 47%, or at least 50% relative to the axial height Hb of the body 101. In another example, the third axial height Har3 may be at most 50% relative to the axial height Hb of the body 101, such as at most 47%, at most 44%, at most 41%, at most 38%, at most 35%, at most 33%, at most 30%, at most 27%, at most 25%, at most 22%, at most 20%, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, at most 5%, at most 3%, or at most 2% relative to the axial height Hb of the body 101. Moreover, the third axial height Har3 may be in a range including any of the minimum and maximum percentages noted herein. For example, the third axial height Har3 may be in a range from 1% to 50% or in a range from 2% to 30% or in a range from 4% to 24%.

[0084] In a further embodiment, the first, second, or third axial height may be at least 1mm, such as at least 3mm, at least 5mm, at least 7mm, at least 8mm, at least 10mm, at least 11mm, at least 13mm, at least 15mm, at least 18mm, or at least 20mm. Alternatively or additionally, the first, second, or third axial height may be at most 30mm, at most 28mm, at most 25mm, at most 23mm, at most 20mm, at most 18mm, at most 15mm, at most 12mm, at most 10mm, at most 8mm, at most 7mm, at most 5mm, at most 4mm, at most 3mm, or at most 2mm. Moreover, the first, second, or third axial height may be in a range including any of the minimum and maximum values noted herein. For example, the first, second, or third axial height may be in a range from 1mm to 30mm or in a range from 3mm to 20mm. In a particular embodiment, the axial height of the first, second, and third abrasive regions may be essentially the same.

[0085] In an embodiment, the outermost abrasive region may be spaced apart from the middle abrasive region by a first non-abrasive portion (e.g., 113 illustrated in FIG. 1) that may include a particular radial thickness t4 (illustrated in FIG. 2) that may facilitate improved performance and / or formation of the abrasive article. For example, the radial thickness t4 may be at least 1% relative to the outer diameter DI of the body (e.g., 101 illustrated in FIGs. 1-2, such as at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 10%, at least 12%, or at least 15% relative to the outer diameter DI of the body 101. In another example, the first non-abrasive portion may include the radial thickness t4 of at most 20% relative to the outer diameter DI of the body 101, such as at most 19%, at most 18%, at most 16%, at most 15%, at most 12%, at most 10%, at most 8%, at most 7%, at most 6%, at most 5%, at most 4%, at most 3%, or at most 2% relative to the outer diameter DI of the body 101. Moreover, the radial thickness t4 may be in a range including any of the minimum and maximum percentages noted herein. For example, the radial thickness t4 may be in a range from 1% to 20% or in a range from 1% to 20% or in a range from 1% to 14% or in a range from 1% to 10% or in a range from 1% to 8% or in a range from 2% to 6%.

[0086] In an embodiment, the middle abrasive region and the innermost abrasive region may be spaced apart by a second non-abrasive portion (e.g., 115 illustrated in FIG. 2) may include a particular radial thickness t5 (illustrated in FIG. 2) that may facilitate improved performance and / or formation of the abrasive article. For example, the radial thickness t5 may be at least 1% relative to the outer diameter DI of the body 101 (illustrated in FIGs. 1- 2), such as at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 10%, at least 12%, or at least 15% relative to the outer diameter DI of the body 101. In another example, the second non-abrasive portion 115 may include the radial thickness t4 of at most 20% relative to the outer diameter DI of the body 101, such as at most 19%, at most 18%, at most 16%, at most 15%, at most 12%, at most 10%, at most 8%, at most 7%, at most 6%, at most 5%, at most 4%, at most 3%, or at most 2% relative to the outer diameter DI of the body 101. Moreover, the radial thickness t5 may be in a range including any of the minimum and maximum percentages noted herein. For example, the radial thickness t5 may be in a range from 1% to 20% or in a range from 1% to 20% or in a range from 1% to 14% or in a range from 1% to 10% or in a range from 1% to 8% or in a range from 2% to 6%.

[0087] In an embodiment, a radial thickness of a non-abrasive portion may be the same of different than a radial thickness of an adjacent abrasive region. For example, the radial thickness of a non-abrasive portion may be greater than a radial thickness of an adjacent abrasive region. In another example, the radial thickness of a non-abrasive portion immediately between abrasive regions may be greater than the radial thickness of one or both of the abrasive regions.

[0088] In a further embodiment, one or more or all of the innermost, middle, and outermost abrasive regions may include a plurality of abrasive portions, wherein adjacent abrasive portions may be separated by a non-abrasive portion. In a further embodiment, the body may include at least 3, at least 4, or more non-abrasive portions that alternate with abrasive portions. In another embodiment, each non-abrasive portion may include any features described with respect with the first or second non-abrasive portion.

[0089] In an embodiment, the body may include a work surface that may include at least a portion of a surface area of each of the first abrasive region, the second abrasive region, and the third abrasive region. In a particular embodiment, the work surface of the body (e.g., the body 101 illustrated in FIGs. 1 and 2) may include a first work surface 133 of the first abrasive region 103, a second work surface 134 of the second abrasive region 104, and a third work surface 135 of the third abrasive region 105 (illustrated in FIGs. 1-2). In a further embodiment, the first abrasive region 103 may be configured to wear at a first wear rate, and the second abrasive region 104 may be configured to wear at a second wear rate, wherein a difference between the first and second wear rate may be within 10% of bigger of the first and second wear rate, such as within 9%, within 7%, within 5%, within 3% or within 1% of the bigger of the first and second wear rate. In another embodiment, the third abrasive region may be configured to wear at a third wear rate, wherein a difference between the third and second wear rate may be within 10% of the bigger of the second and third wear rate, such as within 9%, within 7%, within 5%, within 3% or within 1% of the bigger of the second and second wear rate. In still another embodiment, a difference between the third and first wear rate may be within 10% of bigger of the third and first wear rate, such as within 9%, within 7%, within 5%, within 3% or within 1% of the bigger of the third and first wear rate. In a particular embodiment, the first, second, and third abrasive regions are configured to wear at essentially the same rate.

[0090] In a further embodiment, the body may include a total surface area of the non- abrasive portions that may facilitate improved performance the abrasive article. In another embodiment, the body may include a particular ratio RSN / SA of the total surface area of the non-abrasive portions to the total surface area of the abrasive regions that may facilitate improved performance and / or formation of the abrasive article. For example, the body may include at least 50% of the total surface area of the non-abrasive portions relative to the total surface area of the abrasive regions, such as at least 60%, at least 68%, at least 70%, at least 73%, at least 75%, at least 78%, at least 80%, at least 90%, at least 100%, at least 120%, at least 130%, at least 140%, at least 150%, at least 160%, at least 167%, at least 170%, at least 180%, at least 190%, at least 200%, at least 210%, at least 220%, at least 230%, at least 240%, or at least 250% of the total surface area of non-abrasive portion relative to the total surface area of the abrasive regions. In another example, the body may include at most 250% of the total surface area of the non-abrasive portions relative to the total surface area of the abrasive regions, such as at most 240%, at most 230%, at most 220%, at most 210%, at most 200%, at most 190%, at most 180%,, at most 175%, at most 171%, at most 170%, at most 167%, at most 160%, at most 150%, at most 140%, at most 130%, at most 120%, at most 110%, at most 100%, at most 90%, at most 80%, at most 78%, at most 75%, at most 70%, at most 60%, or at most 50% of the total surface area of non-abrasive portion relative to the total surface area of the abrasive regions. Moreover, the percent total surface area of the nonabrasive portions relative to the total surface area of the abrasive regions may be in a range including any of the minimum and maximum percentages noted herein. After reading this disclosure, a skilled artisan appreciates that the surface area, radial thickness, and / or relative placement of non-abrasive portions of embodiments herein may facilitate improved removal of debris, flow of coolant, or any combination thereof in an abrasive operation.

[0091] In a further embodiment, the body may include a particular ratio, DI / Di, of the outer diameter DI (illustrated in FIG. 1) to the inner diameter Di (illustrated in FIG. 1) that may facilitate improved formation and / or performance of the abrasive article. For example, the body may include the ratio, DI / Di, of at least 10%, such as at least 15%, at least 20%, at least 25%, at least 30%, at least 33%, at least 37%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 73%, at least 77%, or at least 80%. In another example, the body may include the ratio, DI / Di, of at most 80, such as at most 77%, most 75%, at most 70%, at most 68%, at most 65%, at most 63%, at most 60%, at most 56%, at most 53%, at most 50%, at most 45%, at most 40%, at most 35%, at most 32%, at most 30%, at most 25%, at most 20%, at most 15%, or at most 10%. Moreover, the ratio, DI / Di, may be in a range including any of the minimum and maximum percentages noted herein.

[0092] FIG. 3 includes a flowchart illustrating a process 300 of forming the abrasive article according to an embodiment. At block 302, a mixture can be made including a bond material and / or precursor bond material and abrasive particles. The bond and / or precursor bond material may be liquid, powder, or a combination thereof. An exemplary bond and / or bond precursor material may include one or more resins, such as phenolic resins, epoxy resins, polyester resins, polyurethanes, polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide, modified phenolic resins (e.g., epoxy modified and rubber modified resins, or phenolic resin blended with plasticizers, etc.), or the like, or any combination thereof. In a particular embodiment, the bond and / or precursor bond material may include phenolic resins. In a particular example, the bond and / or precursor bond material can include a phenolic resin having cross-linked domains having a sub-micron average size. The bond material and / or precursor bond material may further include a curing agent or a cross-link agent. An exemplary curing or cross-link agent may include an amine, such as ethylene diamine, ethylene triamine, methyl amines, or the like. A particular example may include hexamethylene tetramine. Another particular example of the bond and / or precursor bond material may include phenolic resins modified with a curing or cross-linking agent, such as hexamethylene tetramine-modified phenolic resins.

[0093] The mixture may optionally include one or more optional additives, including for example, secondary abrasive particles, fillers, or the like, or any combination thereof. In certain instances, a mixing device may be utilized to help obtain a homogenous mixture.

[0094] After reading this disclosure, a skilled artisan appreciates that separate mixtures may be formed for forming abrasive regions described in embodiments herein.

[0095] The process 300 may continue to block 304 after forming one or more mixtures. In an embodiment, the process 300 may include forming a green abrasive region including abrasive particles contained in the bond and / or bond precursor material. A green abrasive region or body is an abrasive region or body that is unfinished and may undergo further processing before a finally-formed abrasive region or body is formed. Forming of a green abrasive region can include techniques such as pressing, molding, casting, printing, spraying, or a combination thereof. In one particular embodiment, forming of a green abrasive region can include pressing the mixture into a particular shape, including for example, conducting a pressing operation to form a green abrasive region in the annular shape.

[0096] In an embodiment, the process 300 may include forming a plurality of green abrasive regions from suitable mixtures.

[0097] The process 300 may continue by treating one or more green abrasive regions to form one or more finally-formed abrasive regions. Some suitable examples of treating can include curing, heating, sintering, crystallizing, polymerization, pressing, or any combination thereof.

[0098] In one example, the process may include treating green abrasive regions at a final curing temperature of the bond and / or precursor bond material. For example, the curing temperature can be in the range from 150°C to 250° C, such as in the range from 150°C to 230° C, in a range from 110° C to 225°C, or in a range of from 140° C to 225° C. Certain novolac resins suitable for embodiments herein may cure at a temperature in a range from 110° C to 195° C. In a further example, green abrasive regions may be held at the final cure temperature for a period of time, such as between 6 hours and 48 hours, between 10 and 36 hours, or until the green abrasive regions reach the cross-linking temperature or desired density is obtained. After abrasive regions are formed, the process 300 may continue to block 306 to form the abrasive article including a finally-formed body. The abrasive regions may be attached to a major surface of a substrate. In an embodiment, an adhesive may be used to facilitate attachment of abrasive regions. An exemplary adhesive may include a pressure sensitive adhesive, a hot melt, a two-part adhesive, or the like. A particular suitable adhesive may include an epoxy. In a further embodiment, abrasive regions may be bonded to the substrate via the adhesive to form the body. In a further embodiment, the body may be further treated to have a desired shape, such as a wheel, a disc, or the like.

[0099] In an embodiment, a grinding system may include one or more abrasive articles. FG. 4 includes an illustration of a system 400 including a grinding apparatus 430 including exemplary abrasive articles 401 and 403 mounted on the shaft 410 according to an embodiment. The abrasive articles 401 and 403 may be similar to the abrasive article 101 of FIG. 1. The work surfaces of the abrasive articles 401 and 403 may face each other. At least a portion of a workpiece 402 may be positioned between the work surfaces such that opposite surfaces of the workpiece 402 may be ground simultaneously or separately in a grinding operation. As illustrated, in a particular operation, the abrasive body 401 may rotate in the direction 404, the abrasive body 403 may rotate in the direction 405, and the workpiece 402 may rotate in the direction 406 for grinding the opposite surfaces of the workpiece 402.

[0100] FIG. 11 includes a top-down view of an abrasive article 1100 including a body 1101 according to an embodiment. The outermost abrasive region 1102 may include abrasive portions 1121 and 1122 that are spaced apart from each other by a non-abrasive portion 1151. In the illustrated particular embodiment, the middle abrasive region 1103 may be in contact with the abrasive portion 1121 while spaced apart from the abrasive portion 1122. In a particular embodiment, the outermost abrasive region 1102 may include an average abrasive particle size including any values disclosed with respect to the first abrasive region.

[0101] The middle abrasive region 1103 may be spaced apart from the innermost abrasive region 1104 by a second non-abrasive portion 1152. As illustrated, each of the abrasive regions 1102, 1103, and 1104 can include a plurality of abrasive segments that may be spaced apart from one another.

[0102] After reading the present disclosure, a skilled artisan appreciates that an inner abrasive region may include abrasive portions, wherein one of the abrasive portions may be in contact with the middle abrasive region while spaced apart from another abrasive portion that may be positioned closer to the central opening by a non-abrasive portion. In a further embodiment, the middle abrasive region may be in contact with an abrasive portion of the outermost abrasive region and an abrasive portion of the innermost abrasive region. EMBODIMENTS

[0103] Embodiment 1. An abrasive article, comprising a body comprising a plurality of abrasive regions comprising: a first abrasive region comprising first abrasive particles having a first average particle size; and a second concentric abrasive region comprising second abrasive particles having a second average particle size greater than the first average particle size, wherein the second abrasive region is spaced apart from the first abrasive region and comprises a smaller diameter than the first abrasive region.

[0104] Embodiment 2. The abrasive article of embodiment 1, wherein the body comprises an inner diameter (Di) defining a center region of the body and an outermost diameter (DI) defining an outer circumference of the body, wherein a percent surface area of the plurality of abrasive regions is at least 30% and not greater than 70% relative to a surface area of the body between Di and DI .

[0105] Embodiment 3. The abrasive article of embodiment 1 or 2, wherein the body comprises an annular non-abrasive portion between the first and second abrasive regions.

[0106] Embodiment 4. The abrasive article of any one of embodiments 1 to 3, wherein the plurality of abrasive regions comprise a third abrasive region concentric with the first and second abrasive regions, wherein the third abrasive region comprises a diameter smaller than the second abrasive region and third abrasive particles having a third average abrasive particle size smaller than the second average abrasive particle size.

[0107] Embodiment 5. The abrasive article of embodiment 4, wherein the body comprises an annular non-abrasive portion between the third and second abrasive regions.

[0108] Embodiment 6. The abrasive article of embodiment 4 or 5, wherein the first abrasive region, the second abrasive region, or the third abrasive region is annular.

[0109] Embodiment 7. The abrasive article of any one of embodiments 4 to 6, wherein the body comprises a surface including a center opening, wherein the first, second, and third abrasive regions are coupled to the surface and concentric with the center opening.

[0110] Embodiment 8. The abrasive article of any one of embodiments 4 to 7, wherein the first abrasive region, the second abrasive region, or the third abrasive region comprises abutting abrasive segments, abrasive segments that are spaced apart, or any combination thereof. Embodiment 9. The abrasive article of any one of embodiments 4 to 7, wherein the first abrasive region, the second abrasive region, or the third abrasive region is not segmented.

[0111] Embodiment 10. The abrasive article of any one of embodiments 7 to 9, wherein the surface is annular and the abrasive portion is coupled to the surface via an adhesive.

[0112] Embodiment 11. The abrasive article of any one of embodiments 4 to 10, wherein the first abrasive region, the second abrasive region, or the third abrasive region comprises a bond material comprising an organic material.

[0113] Embodiment 12. The abrasive article of embodiment 11, wherein the bond material of each of the first abrasive region, the second abrasive region and the third abrasive region comprises a same organic material.

[0114] Embodiment 13. The abrasive article of any one of embodiments 4 to 12, wherein the first abrasive particles, the second abrasive particles, or the third abrasive particles comprise a superabrasive material, an oxide, a carbide, a nitride, or any combination thereof, wherein the first abrasive particles, the second abrasive particles, or the third abrasive particles comprise diamond, cBN, or a combination thereof, A12O3, SiC, CeO2, or any combination thereof.

[0115] Embodiment 14. The abrasive article of any one of embodiments 1 to 13, wherein the first average particle size is at least 1 microns, at least 3 microns, at least 5 microns, at least 8 microns, at least 10 microns, at least 13 microns, at least 15 microns, at least 17 microns, at least 19 microns, at least 20 microns, at least 23 microns, at least 25 microns, at least 28 microns, at least 32 microns, at least 35 microns, at least 37 microns, at least 40 microns, at least 43 microns, or at least 45 microns; or wherein the first average particle size is at most 150 microns, at most 130 microns, at most 100 microns, at most 95 microns, at most 90 microns, at most 85 microns, at most 80 microns, at most 75 microns, at most 70 microns, at most 65 microns, at most 60 microns, at most 55 microns, at most 50 microns, at most 45 microns, at most 40 microns, at most 35 microns, at most 30 microns, at most 27 microns, at most 25 microns, at most 22 microns, or at most 20 microns; or wherein the first average particle size is within a range from 1 micron to 100 microns, within a range from 5 microns to 85 microns, within a range from 8 microns to 65 microns, or within a range from 10 microns to 20 microns.

[0116] Embodiment 15. The abrasive article of any one of embodiments 1 to 14, wherein the second average particle size is at least 10 microns, at least 13 microns, at least 15 microns, at least 17 microns, at least 19 microns, at least 20 microns, at least 25 microns, at least 30 microns, at least 35 microns, at least 40 microns, at least 40 microns, at least 45 microns, at least 50 microns, at least 55 microns, at least 60 microns, at least 65 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 110 microns, at least 130 microns, at least 150 microns, at least 180 microns, at least 200 microns, at least 250 microns, at least 300 microns, at least 350 microns, or at least 400 microns; or wherein the second average particle size is at most 500 microns, at most 450 microns, at most 400 microns, at most 350 microns, at most 300 microns, at most 250 microns, at most 200 microns, at most 150 microns, at most 100 microns, at most 90 microns, at most 85 microns, at most 80 microns, at most 75 microns, at most 70 microns, at most 65 microns, at most 60 microns, at most 55 microns, at most 50 microns, at most 45 microns, at most 40 microns, at most 35 microns, at most 30 microns, at most 27 microns, at most 25 microns, at most 22 microns, or at most 20 microns; or wherein the second average particle size is within a range from 10 micron to 500 microns, within a range from 15 microns to 400 microns, within a range from 20 microns to 300 microns, or within a range from 30 microns to 200 microns.

[0117] Embodiment 16. The abrasive article of any one of embodiments 1 to 15, wherein the body comprises a particle size ratio of the second average particle size to the first average particle size of at least 1.1 : 1, such as at least 1.3: 1, at least 1.5: 1, at least 1.7: 1, at least 1.9: 1, at least 2.2: 1, at least 2.5: 1, at least 2.8: 1, at least 3.1 : 1, or at least 3.5: 1; or wherein the particle size ratio of the second average particle size to the first average particle size is at most 5: 1, such as at most 4.8: 1, at most 4.6: 1, at most 4.4: 1, at most 4.2: 1, at most 4.0: 1, at most 3.8: 1, at most 3.6: 1, at most 3.5: 1, at most 3.3: 1, at most 3.1 : 1, at most 2.8: 1, at most 2.6: 1, at most 2.4: 1, at most 2.2: 1, at most 1.8: 1, or at most 1.5: 1.

[0118] Embodiment 17. The abrasive article of any one of embodiments 4 to 16, wherein the third average particle size is at least 1 microns, at least 3 microns, at least 5 microns, at least 8 microns, at least 10 microns, at least 13 microns, at least 15 microns, at least 17 microns, at least 19 microns, at least 20 microns, at least 23 microns, at least 25 microns, at least 28 microns, at least 32 microns, at least 35 microns, at least 37 microns, at least 40 microns, at least 43 microns, or at least 45 microns; or wherein the third average particle size is at most 150 microns, at most 130 microns, at most 100 microns, at most 95 microns, at most 90 microns, at most 85 microns, at most 80 microns, at most 75 microns, at most 70 microns, at most 65 microns, at most 60 microns, at most 55 microns, at most 50 microns, at most 45 microns, at most 40 microns, at most 35 microns, at most 30 microns, at most 27 microns, at most 25 microns, at most 22 microns, or at most 20 microns; or wherein the third average particle size is within a range from 1 micron to 100 microns, within a range from 5 microns to 85 microns, within a range from 8 microns to 65 microns, or within a range from 10 microns to 20 microns.

[0119] Embodiment 18. The abrasive article of any one of embodiments 4 to 17, wherein the abrasive portion comprises a particle size ratio of the second average particle size to the third average particle size of at least 1.1, at least 1.3, at least 1.5, at least 1.7, at least 1.9, at least 2.2, at least 2.5, at least 2.8, at least 3.1, or at least 3.5; or wherein the particle size ratio of the second average particle size to the third average particle size is at most 5: 1, such as at most 4.8: 1, at most 4.6: 1, at most 4.4: 1, at most 4.2: 1, at most 4.0: 1, at most 3.8: 1, at most 3.6: 1, at most 3.5: 1, at most 3.3: 1, at most 3.1 : 1, at most 2.8: 1, at most 2.6: 1, at most 2.4: 1, at most 2.2: 1, at most 1.8: 1, or at most 1.5: 1.

[0120] Embodiment 19. The abrasive article of any one of embodiments 4 to 18, wherein the first average particle size is essentially same as the third average particle size; or wherein the first average particle size is different than the third average particle size; and wherein the second average particle size is greater than the first average particle size.

[0121] Embodiment 20. The abrasive article of any one of embodiments 1 to 19, wherein the first abrasive region comprises a first abrasive particle content for a volume of the first abrasive region, the second abrasive region comprises a second abrasive particle content for a volume of the second abrasive region, and the third abrasive region comprises a third abrasive particle content for a volume of the third abrasive region, wherein the first, second, or third abrasive particle content is independently at least 1 vol%, at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, at least 20 vol%, at least 25 vol%, at least 27 vol%, at least 30 vol%, at least 34 vol%, at least 38 vol%, at least 40 vol%, at least 42 vol%, at least 45 vol%, at least 48 vol%, at least 50 vol%, at least 53 vol%, or at least 55 vol%; or wherein the first, second, or third abrasive particle content is independently at most 60 vol%%, at most 57 vol%, at most 55 vol%, at most 52 vol%, at most 50 vol%, at most 47 vol%, at most 45 vol%, at most 43 vol%, at most 40 vol%, at most 38 vol%, at most 35 vol%, at most 32 vol%, at most 30 vol%, at most 27 vol%, at most 24 vol%, at most 22 vol%, at most 20 vol%, at most 17 vol%, at most 15 vol%, at most 13 vol%, or at most 11 vol%.

[0122] Embodiment 21. The abrasive article of embodiment 20, wherein the first, second, and third abrasive particle contents are essentially same; or wherein at least two of the first, second, and third abrasive particle content are different.

[0123] Embodiment 22. The abrasive article of any one of embodiments 1 to 21, wherein the body comprises a ratio of abrasive particle content of the first abrasive region to the second abrasive region of at least 0.1, at least 0.4, at least 0.6, at least 0.8, at least 1.0, at least 1.2, at least 1.5, at least 1.8, at least 2.0, at least 2.4, at least 2.7, at least 3.0, at least 3.2, at least 3.5, at least 3.8, at least 4, at least 4.2, at least 4.5, at least 4.8, at least 5.0, at least 5.3, at least 5.6, at least 6.0, at least 6.5, at least 6.8, at least 7, or at least 7.2; or wherein the ratio of abrasive particle content of the first abrasive region to the second abrasive region is at most 10, at most 9.5, at most 9, at most 8.7, at most 8.5, at most 8, at most 7.5, at most 7.2, at most 7.0, at most 6.8, at most 6.6, at most 6.2, at most 6, at most 5.7, at most 5.4, at most 5.2, at most 5.0, at most 4.8, at most 4.5, at most 4.2, at most 4.0, at most 3.8, at most 3.6, at most 3.2, at most 3, at most 2.8, at most 2.5, at most 2.2, at most 2.0, at most 1.8, at most 1.6, at most 1.4, at most 1.2, or at most 1.0.

[0124] Embodiment 23. The abrasive article of any one of embodiments 4 to 22, wherein the body comprises a ratio of abrasive particle content of the third abrasive region to the second abrasive region of at least 0.1, at least 0.4, at least 0.6, at least 0.8, at least 1.0, at least 1.2, at least 1.5, at least 1.8, at least 2.0, at least 2.4, at least 2.7, at least 3.0, at least 3.2, at least 3.5, at least 3.8, at least 4, at least 4.2, at least 4.5, at least 4.8, at least 5.0, at least 5.3, at least 5.6, at least 6.0, at least 6.5, at least 6.8, at least 7, or at least 7.2; or wherein the ratio of abrasive particle content of the third abrasive region to the second abrasive region is at most 10, at most 9.5, at most 9, at most 8.7, at most 8.5, at most 8, at most 7.5, at most 7.2, at most 7.0, at most 6.8, at most 6.6, at most 6.2, at most 6, at most 5.7, at most 5.4, at most 5.2, at most 5.0, at most 4.8, at most 4.5, at most 4.2, at most 4.0, at most 3.8, at most 3.6, at most 3.2, at most 3, at most 2.8, at most 2.5, at most 2.2, at most 2.0, at most 1.8, at most 1.6, at most 1.4, at most 1.2, or at most 1.0.

[0125] Embodiment 24. The abrasive article of any one of embodiments 4 to 23, wherein the body comprises a ratio of abrasive particle content of the third abrasive region to the first abrasive region of at least 0.1, at least 0.4, at least 0.6, at least 0.8, at least 1.0, at least 1.2, at least 1.5, at least 1.8, at least 2.0, at least 2.4, at least 2.7, at least 3.0, at least 3.2, at least 3.5, at least 3.8, at least 4, at least 4.2, at least 4.5, at least 4.8, at least 5.0, at least 5.3, at least 5.6, at least 6.0, at least 6.5, at least 6.8, at least 7, or at least 7.2; or wherein the ratio of abrasive particle content of the third abrasive region to the first abrasive region is at most 10, at most 9.5, at most 9, at most 8.7, at most 8.5, at most 8, at most 7.5, at most 7.2, at most 7.0, at most 6.8, at most 6.6, at most 6.2, at most 6, at most 5.7, at most 5.4, at most 5.2, at most 5.0, at most 4.8, at most 4.5, at most 4.2, at most 4.0, at most 3.8, at most 3.6, at most 3.2, at most 3, at most 2.8, at most 2.5, at most 2.2, at most 2.0, at most 1.8, at most 1.6, at most 1.4, at most 1.2, or at most 1.0. Embodiment 25. The abrasive article of any one of embodiments 20 to 24, wherein at least two of the first, second, and third abrasive particle contents are different, wherein a difference between the at least two of the first, second, and third abrasive particle contents is within ±15%, within ±12%, within ±8%, or within ±5% of bigger of the at least two abrasive particle contents.

[0126] Embodiment 26. The abrasive article of any one of embodiments 1 to 25, wherein the first abrasive region comprises a plurality of segments comprising a first average content of the first abrasive particles, wherein the first average content is at least 1 vol%, at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, at least 20 vol%, at least 25 vol%, at least 27 vol%, at least 30 vol%, at least 34 vol%, at least 38 vol%, at least 40 vol%, at least 42 vol%, at least 45 vol%, at least 48 vol%, at least 50 vol%, at least 53 vol%, or at least 55 vol%; or wherein the first average content of the first abrasive particles is at most 60 vol%, at most 57 vol%, at most 55 vol%, at most 52 vol%, at most 50 vol%, at most 47 vol%, at most 45 vol%, at most 43 vol%, at most 40 vol%, at most 38 vol%, at most 35 vol%, at most 32 vol%, at most 30 vol%, at most 27 vol%, at most 24 vol%, at most 22 vol%, at most 20 vol%, at most 17 vol%, at most 15 vol%, at most 13 vol%, or at most 11 vol%.

[0127] Embodiment 27. The abrasive article of embodiment 26, wherein the first abrasive region comprises a fixed interval between adjacent abrasive segments, wherein intervals between adjacent segments are substantially same.

[0128] Embodiment 28. The abrasive article of any one of embodiments 1 to 27, wherein the second abrasive region comprises a plurality of segments comprising a second average content of the second abrasive particles of at least 1 vol%, at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, at least 20 vol%, at least 25 vol%, at least 27 vol%, at least 30 vol%, at least 34 vol%, at least 38 vol%, at least 40 vol%, at least 42 vol%, at least 45 vol%, at least 48 vol%, at least 50 vol%, at least 53 vol%, or at least 55 vol%; or wherein the second average content of the second abrasive particles is at most 60 vol%, at most 57 vol%, at most 55 vol%, at most 52 vol%, at most 50 vol%, at most 47 vol%, at most 45 vol%, at most 43 vol%, at most 40 vol%, at most 38 vol%, at most 35 vol%, at most 32 vol%, at most 30 vol%, at most 27 vol%, at most 24 vol%, at most 22 vol%, at most 20 vol%, at most 17 vol%, at most 15 vol%, at most 13 vol%, or at most 11 vol%. Embodiment 29. The abrasive article of embodiment 28, wherein the second abrasive region comprises a fixed interval between adjacent abrasive segments, wherein intervals between adjacent segments are substantially same.

[0129] Embodiment 30. The abrasive article of any one of embodiments 4 to 29, wherein the third abrasive region comprises a plurality of segments comprising a third average content of the third abrasive particles of at least 1 vol%, at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, at least 20 vol%, at least 25 vol%, at least 27 vol%, at least 30 vol%, at least 34 vol%, at least 38 vol%, at least 40 vol%, at least 42 vol%, at least 45 vol%, at least 48 vol%, at least 50 vol%, at least 53 vol%, or at least 55 vol%; or wherein the third average content of the third abrasive particles is at most 60 vol%, at most 57 vol%, at most 55 vol%, at most 52 vol%, at most 50 vol%, at most 47 vol%, at most 45 vol%, at most 43 vol%, at most 40 vol%, at most 38 vol%, at most 35 vol%, at most 32 vol%, at most 30 vol%, at most 27 vol%, at most 24 vol%, at most 22 vol%, at most 20 vol%, at most 17 vol%, at most 15 vol%, at most 13 vol%, or at most 11 vol%.

[0130] Embodiment 31. The abrasive article of embodiment 30, wherein the third abrasive region comprises a fixed interval between adjacent abrasive segments, wherein intervals between adjacent segments are substantially same.

[0131] Embodiment 32. The abrasive article of any one of embodiments 1 to 31, wherein the first abrasive region comprises a first bond content for a total volume of the first abrasive region, the second abrasive region comprises a second bond content for a total volume of the second abrasive region, and the third abrasive region comprises a third bond content for a total volume of the third abrasive region, wherein the first, second, or third bond content is independently at least 40 vol%, at least 42 vol%, at least 45 vol%, at least 48 vol%, at least 50 vol%, at least 53 vol%, at least 55 vol%, at least 58 vol%, at least 61 vol%, at least 64 vol%, at least 68 vol%, at least 70 vol%, at least 73 vol%, at least 75 vol%, at least 77 vol%, or at least 80 vol; or wherein the first, second, or third bond content is independently at most 98 vol%, at most 95 vol%, at most 92 vol%, at most 90 vol%, at most 85 vol%, at most 82 vol%, at most 78 vol%, at most 75 vol%, at most 72 vol%, at most 68 vol%, at most 64 vol%, at most 60 vol%, at most 57 vol%, at most 55 vol%, at most 52 vol%, at most 50 vol%, at most 47 vol%, or at most 45 vol%.

[0132] Embodiment 33. The abrasive article of any one of embodiments 4 to 32, wherein the first, second, or third abrasive region independently comprises a filler material including lime, graphite, SiC, A12O3, copper, or any combination thereof. Embodiment 34. The abrasive article of embodiment 32, wherein the first abrasive region comprises a first filler content for a total volume of the first abrasive region, the second abrasive region comprises a second filler content for a total volume of the second abrasive region, and the third abrasive region comprises a third filler content for a total volume of the third abrasive region, wherein the first, second, or third filler content is independently at least 0.5 vol%, at least 1 vol%, at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, at least 20 vol%, at least 25 vol%, at least 27 vol%, at least 30 vol%, at least 34 vol%, at least 38 vol%, or at least 40 vol%; or wherein the first, second, or third filler content is at most 40 vol%, at most 38 vol%, at most 35 vol%, at most 32 vol%, at most 30 vol%, at most 27 vol%, at most 24 vol%, at most 22 vol%, at most 20 vol%, at most 17 vol%, at most 15 vol%, at most 13 vol%, at most 11 vol%, at most 9 vol%, at most 7 vol%, at most 5 vol%, at most 3 vol%, or at most 2 vol%.

[0133] Embodiment 35. The abrasive article of any one of embodiments 4 to 34, wherein the first, second, or third abrasive region comprises a porosity; or wherein the first, second, or third abrasive region is essentially free of porosity.

[0134] Embodiment 36. The abrasive article of any one of embodiments 4 to 34, wherein the first abrasive region comprises a first porosity for a total volume of the first abrasive region, the second abrasive region comprises a second porosity for a total volume of the second abrasive region, and the third abrasive region comprises a third porosity for a total volume of the third abrasive region, wherein the first, second, or third porosity is independently at least 0.5 vol%, at least 1 vol%, at least 3 vol%, at least 5 vol%, at least 8 vol%, at least 10 vol%, at least 13 vol%, at least 15 vol%, at least 18 vol%, or at least 20 vol%; or wherein the first, second, or third porosity is at most 20 vol%, at most 17 vol%, at most 15 vol%, at most 13 vol%, at most 11 vol%, at most 9 vol%, at most 7 vol%, at most 5 vol%, at most 3 vol%, at most 2 vol%, at most 1 vol%, or at most 0.5 vol%.

[0135] Embodiment 37. The abrasive article of any one of embodiments 4 to 36, wherein the first abrasive region comprises a first percent abrasive surface area for a total surface area of the abrasive portion, and the third abrasive region comprises a third percent abrasive surface area for a total surface area of the abrasive portion, wherein the first or third percent abrasive surface area is independently at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, or at least 45%; or wherein the first or third percent abrasive surface area is independently at most 50%, at most 45%, at most 40%, at most 35%, at most 30%, at most 25%, or at most 20%. Embodiment 38. The abrasive article of any one of embodiments 1 to 37, wherein the second abrasive region comprises a second percent abrasive surface area of at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70%; or wherein the second percent abrasive surface area is at most 80% for a total surface area of the abrasive portion, at most 75%, at most 70%, at most 65%, at most 60%, at most 55%, at most 50%, at most 45%, at most 40%, at most 35%, at most 30%, at most 25%, or at most 20%.

[0136] Embodiment 39. The abrasive article of any one of embodiments 1 to 28, comprising a surface area ratio of the first abrasive region to the second abrasive region of at least 1 : 10, at least 1 :9, at least 1 :8, at least 1 :7, at least 1 :6, at least 1 :5, at least 1 :3, at least 1 : 1, at least 2: 1, at least 3: 1, at least 4: 1, or at least 5: 1; wherein the surface area ratio of the first abrasive region to the second abrasive region is at most 10: 1, at most 9: 1, at most 8:1, at most 7: 1, at most 6: 1, at most 5: 1, at most 4: 1, at most 2: 1, at most 1 : 1, at most 1 :2, at most 1 :4, or at most 1 :5.

[0137] Embodiment 40. The abrasive article of any one of embodiments 4 to 39, comprising a surface area ratio of the first abrasive region to the third abrasive region of at least 1 : 10, at least 1 :9, at least 1 :8, at least 1 :7, at least 1 :6, at least 1 :5, at least 1 :3, at least 1 : 1, at least 2: 1, at least 3: 1, at least 4: 1, or at least 5: 1; wherein the surface area ratio of the first abrasive region to the second abrasive region is at most 10: 1, at most 9: 1, at most 8:1, at most 7: 1, at most 6: 1, at most 5: 1, at most 4: 1, at most 2: 1, at most 1 : 1, at most 1 :2, at most 1 :4, or at most 1 :5.

[0138] Embodiment 41. The abrasive article of any one of embodiments 4 to 40, comprising a surface area ratio of the second abrasive region to the third abrasive region of at least 1 : 10, at least 1 :9, at least 1 :8, at least 1 :7, at least 1 :6, at least 1 :5, at least 1 :3, at least 1 : 1, at least 2: 1, at least 3: 1, at least 4: 1, or at least 5: 1; wherein the surface area ratio of the first abrasive region to the second abrasive region is at most 10: 1, at most 9: 1, at most 8:1, at most 7: 1, at most 6: 1, at most 5: 1, at most 4: 1, at most 2: 1, at most 1 : 1, at most 1 :2, at most 1 :4, or at most 1 :5.

[0139] Embodiment 42. The abrasive article of any one of embodiments 4 to 41, wherein the first, second, or third abrasive region comprises a radial thickness of at least 1% relative to an outer dimeter of the body, at least 2%, at least 5%, at least 7%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 22%, at least 25%, at least 28%, at least 30%, at least 33%, or at least 35% relative to the outer dimeter of the body; or wherein the first, second, or third abrasive region comprises a radial thickness of at most 35% relative to an outer dimeter of the body, at most 33%, at most 30%, at most 27%, at most 25%, at most 22%, at most 20%, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, at most 5%, at most 3%, or at most 2% relative to the outer dimeter of the body.

[0140] Embodiment 43. The abrasive article of any one of embodiments 4 to 42, wherein the first, second, or third abrasive region comprises an axial height of at least 1% relative to a total axial height of the body, at least 3%, at least 5%, at least 7%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 22%, at least 25%, at least 28%, at least 30%, at least 33%, at least 35%, at least 38%, at least 40%, at least 42%, at least 45%, at least 47%, or at least 50% relative to the total axial height of the body; or wherein the first, second, or third abrasive region comprises an axial height of at most 50% relative to the total axial height of the body, at most 47%, at most 44%, at most 41%, at most 38%, at most 35%, at most 33%, at most 30%, at most 27%, at most 25%, at most 22%, at most 20%, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, at most 5%, at most 3%, or at most 2% relative to the total axial height of the body.

[0141] Embodiment 44. The abrasive article of embodiment 43, wherein the axial height of the first, second, and third abrasive regions is essentially the same.

[0142] Embodiment 45. The abrasive article of any one of embodiments 1 to 44, wherein the first abrasive region and the second abrasive region is spaced apart by an annual non-abrasive portion, wherein the annual non-abrasive portion comprises a radial thickness of at least 5% relative to an outer diameter of the body, at least 7%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, or at least 20% relative to the outer diameter of the body; or wherein the first abrasive region and the second abrasive region is spaced apart by an annual non-abrasive portion, wherein the annual non-abrasive portion comprises a radial thickness of at most 20% relative to the outer diameter of the body, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, or at most 5% relative to the outer diameter of the body.

[0143] Embodiment 46. The abrasive article of any one of embodiments 4 to 45, wherein the third abrasive region and the second abrasive region is spaced apart by an annual non- abrasive portion, wherein the annual non-abrasive portion comprises a radial thickness of 5% relative to an outer diameter of the body, at least 7%, at least 8%, at least 10%, at least 12%, at least 15%, at least 18%, or at least 20% relative to the outer diameter of the body; or wherein the third abrasive region and the second abrasive region is spaced apart by an annual non-abrasive portion, wherein the annual non-abrasive portion comprises a radial thickness of at most 20% relative to the outer diameter of the body, at most 17%, at most 15%, at most 12%, at most 10%, at most 8%, at most 6%, or at most 5% relative to the outer diameter of the body.

[0144] Embodiment 47. The abrasive article of any one of embodiments 4 to 46, wherein the body comprises a work surface comprising at least a portion of a surface area of each of the first abrasive region, the second abrasive region, and the third abrasive region.

[0145] Embodiment 48. The abrasive article of any one of embodiments 1 to 47, wherein the first abrasive region is configured to wear at a first wear rate, and the second abrasive region is configured to wear at a second wear rate, wherein a difference between the first and second wear rate is within 10% of bigger of the first and second wear rate.

[0146] Embodiment 49. The abrasive article of embodiment 48, wherein the third abrasive region is configured to wear at a third wear rate, wherein a difference between the third and first wear rate is within 10% of bigger of the first and third wear rate, and wherein a difference between the third and second wear rate is within 10% of bigger of the third and second wear rate.

[0147] Embodiment 50. The abrasive article of any one of embodiments 4 to 49, wherein the first, second, and third abrasive regions are configured to wear at essentially same rate.

[0148] Embodiment 51. The abrasive article of any one of embodiments 4 to 50, wherein at least one of the first, second, and third abrasive regions include a plurality of concentric abrasive portions that are spaced apart from one another.

[0149] Embodiment 52. The abrasive article of any one of embodiments 4 to 51, wherein the first abrasive regions is an outermost abrasive region, the third abrasive region is an innermost abrasive region, and the second abrasive region is a middle abrasive region between the innermost and outermost abrasive region.

[0150] Embodiment 53. A system, comprising at least one abrasive article of any one of embodiments 1 to 5052.

[0151] Embodiment 54. A system, comprising a plurality of abrasive articles of any one of embodiments 1 to 5052, wherein a first abrasive article of the plurality of abrasive articles comprises a first work surface and is mounted such that the first work surface faces a second work surface of a second abrasive article of the plurality of abrasive articles, wherein the first and second abrasive articles are configured to grind opposite surfaces of a work piece simultaneously. EXAMPLES

[0152] Example 1

[0153] A representative abrasive wheel Sample SI is formed according to embodiments herein. The layout of the abrasive regions and non-abrasive portions are similar to the illustration of FIG. 1. A mixture is formed for each abrasive region including 30 wt% of an organic material including phenolic resins and hexamethylene tetramine, 35 wt% of filler SiC, and 35 wt% of diamond abrasive particles for the total weight of the mixture. The mixtures are pressed in a mold separately forming the green abrasive regions and cured at 180 °C for 720 min. The finally-formed abrasive regions are attached to a substrate of aluminum alloy via epoxy adhesives (commercially available as KAFUTER K-960).

[0154] The first (outermost) and third (innermost) abrasive regions of Sample SI include diamond grains having the average particle size of 9pm. The second (middle) abrasive region includes diamond grains having the average particle size of 15 pm. Each of the first, second, and third abrasive regions includes approximately 25 vol% of diamond abrasive particles, 70 vol% of the same bond material, and up to 5 vol% of porosity relative to the total volume of the respective abrasive region. The first abrasive region has a grinding surface area of approximately 40%, the third abrasive region has a grinding surface area of approximately 27%, and the second abrasive region has a grinding surface area of approximately 33% for the total surface area of the first, second, and third abrasive regions. The first annular non-abrasive portion between the first and second and the second annular non-abrasive portion between the second and third abrasive regions have substantially the same radial thickness of approximately 4% of the outer diameter of the wheel. The ratio of the total surface area of the first, second, third regions to the total surface area of the non- abrasive portions of the wheel sample is approximately 3:2.

[0155] Wheel Sample S2 is formed having a similar layout of abrasive regions and non- abrasive portions to SI and the same compositions except that the outermost and innermost abrasive regions of Sample S2 includes diamond grains having the average particle size of 15 pm and the middle abrasive region includes diamond grains having the average particle size of 9 pm.

[0156] A group of 3 wheels samples SI and S2 are tested for grinding workpieces of quartz. 4” x 5 pcs quartz are ground per each wheel sample with the grinding speed at 0.03 mm / min and grinding time of 30 min, respectively. Surface roughness of each workpiece is evaluated using a laser confocal microscope to measure 5 2mmx5mm areas and the average is used as the roughness of a workpiece. The range of roughness and total thickness variation (TTV) of the workpieces ground by each Sample is included in Table 1 below. Sample SI demonstrates significantly improved surface finishing over Sample S2 and achieved satisfactory MRR / time (MRR”). MRR” of 0.020mm / min or higher for the grinding test is considered satisfactory. Total thickness variation of the workpieces is determined by measuring thickness at 7 different locations of each workpiece using thickness gauge.

[0157] Samples SI and S2 achieved similar TTV. TTV less than 10 pm is considered acceptable for the grinding test. Surface roughness Sa of less than 300 nm is considered good surface finish.

[0158] Table 1

[0159] Example 2

[0160] A group of Wheel samples CS3 is formed in a similar manner as Sample SI except one abrasive region is formed having approximately 25 vol% of diamond abrasive particles having the average particle size of 15 pm, 70 vol% of the same bond material as Sample SI, and up to 5 vol% of porosity relative to the total volume of the abrasive region. FIG. 5 includes an illustration of a top-down view Sample CS3 including the abrasive region 501 and non-abrasive portion 502.

[0161] A group of Wheel samples CS4 is formed in a similar manner as Sample SI except one abrasive region is formed having approximately 25 vol% of diamond abrasive particles having the average particle size of 9pm, 70 vol% of the same bond material as Sample SI, and up to 5 vol% of porosity relative to the total volume of the abrasive region. Sample CS4 has a similar top-down view to Sample CS3.

[0162] Another group of 3 wheels of Wheel Sample SI and 3 wheels of each of CS3 and CS4 are tested on quartz grinding using 4” x 5 pcs quartz with the grinding speed at 0.03 mm / min and grinding time of 30 min. Surface roughness of the workpieces is evaluated after the tests are completed using a laser confocal microscope as described in Example 1. MRR” as well as the range of surface roughness of the ground workpieces by each wheel Sample is included in Table 2 below. Sample SI demonstrated improved balance of high MRR” and low surface roughness compared to CS3 and CS4. Sample SI further demonstrated improved TTV compared to Sample CS4 and similar TTV compared to Sample CS3. Table 2

[0163] Example 3

[0164] Abrasive wheel samples are formed having the first (outermost), second (middle), and third (innermost) abrasive regions including diamond abrasive particles. The layouts of the abrasive regions and non-abrasive regions of all the wheel samples are similar to the illustration of FIG. 1. For each wheel sample, diamond abrasive particles in the first and third abrasive regions have substantially the same average particle size of approximately 9 microns. Each wheel sample includes approximately 25 vol% of diamond abrasive particles, 70 vol% of the same bond material, and up to 5 vol% of porosity in the first, second, and third abrasive regions relative to the total volume of the respective abrasive region. For each wheel sample, the first abrasive region has a grinding surface area of approximately 40%, the third abrasive region has a grinding surface area of approximately 27%, and the second abrasive region has a grinding surface area of approximately 33% for the total surface area of the first, second, and third abrasive regions. The annular non-abrasive portion between the first and second and between the second and third abrasive regions has the same radial thickness of approximately 4% of the diameter of the wheel. The ratio of the total surface area of the first, second, third regions to the total surface area of all non-abrasive portions of each wheel sample is approximately 3:2.

[0165] Wheel samples are tested on grinding 4” x 5 pcs quartz. Stock removal per 30 min of the grinding time using the grinding speed of 0.03mm / min and surface roughness of the workpieces are evaluated in the same manner as described in Example 1.

[0166] The particle size ratios of the second to the first abrasive region and grinding test results of the wheel samples are included in Table 3 below. Table 3

[0167] Example 4

[0168] Sets of abrasive wheel samples S21-S23 are formed having the configuration illustrated in FIG. 8 and abrasive particle sizes noted in Table 4 below. Each set includes 3 wheel samples. Each of the abrasive regions of each wheel includes approximately 25 vol% of diamond abrasive particles, 70 vol% of the same bond material, and up to 5 vol% of porosity relative to the total volume of the respective abrasive region. The abrasive region 802 for each wheel has a grinding surface area of approximately 40%, the abrasive region 804 has a grinding surface area of approximately 27%, and the abrasive region 803 has a grinding surface area of approximately 33% for the total surface area of the abrasive regions 802, 803, and 804. Each annular non-abrasive portion between the abrasive regions has substantially the same radial thickness of approximately 2% of the outer diameter of the wheel. The ratio of the total surface area of the abrasive regions 802, 803, and 804 to the total surface area of the non-abrasive portions of each wheel is approximately 3:2.

[0169] The wheel samples are tested on grinding 4” x 5 pcs quartz. Stock removal per 30 min of the grinding time using the grinding speed of 0.03mm / min and surface roughness of the workpieces are evaluated in the same manner as described in Example 1.

[0170] Sets S21 and S22 have similar material removal rates and result in similar surface roughness and TTV on the workpieces. Sets S21 and S22 generate improved surface roughness compared to Set 23 and at the same time have satisfactory material removal rates. Table 4

[0171] Example 5

[0172] Abrasive wheel samples SI 5 to S20 and S27-S29 are formed in the same manner as described with respect to Sample SI . The abrasive wheel samples S15 to S20 and S27-S29 have different percentages of surface areas relative to the total abrasive surface area for the first, second, or third abrasive regions and ratios thereof but the same compositions for each abrasive region to Sample SI.

[0173] Abrasive wheel samples S26 are formed having a similar layout as FIG. 11 except the middle two rings 1103 and 1121 make up the second abrasive region and have the same average particle size of 15 microns, the outer ring 1122 has the average particle size of 9 microns, and the inner ring 1104 has the average particle size of 9 microns. The abrasive regions of Samples S26 have the same compositions as the corresponding abrasive regions of Sample SI. Table 5 includes the percentages of surface areas relative to the total abrasive surface area for the first, second, or third abrasive regions and ratios thereof for the wheel samples.

[0174] The wheel samples are tested for grinding using 4” x 5 pcs quartz with the grinding speed at 0.03 mm / min and grinding time of 30 min.

[0175] Table 5

[0176] Table 6

[0177] The grinding tests are included in Table 6. Samples SI 7, S26, and S28 demonstrate satisfactory MRR”, and improved surface roughness and TTV compared to other samples.

[0178] Example 6

[0179] Abrasive wheel samples S24 and S25 are formed in the same manner as described with respect to Sample SI. The abrasive wheel samples S24 and S25 have the same layout as illustrated in FIG. 11 and the same compositions for each abrasive region except for different abrasive particle sizes, which are noted in Table 7 below. The abrasive regions of Samples S24 and S25 have the same compositions as the corresponding abrasive regions of Sample SI except for abrasive particle sizes indicated below.

[0180] Grinding tests are performed as described in Example 1. Wheel Sample S24 results in improved surface roughness and satisfactory MRR” and TTV compared to S25.

[0181] Table 7

[0182] The foregoing embodiments represent a departure from the state-of-the-art. Embodiments are directed to an abrasive article including a body including concentric abrasive regions and one or more non-abrasive portions alternating with the abrasive regions. The outermost and innermost abrasive regions may include relatively finer abrasive grains, and one or more middle abrasive regions may include relatively coarse abrasive grains. The abrasive article may allow improved material removal rate, such as improved stock removal within a limited time period, and at the same time improved surface finishing of workpieces, such as total thickness variation, surface roughness, or both of workpieces. In particular, improved performance may be facilitated by particular placement of abrasive regions including coarse and fine abrasive particles, placement of the non-abrasive portion, the surface area of abrasive regions, the surface area of the non-abrasive portion, ratios thereof, particle size ratios between coarse and fine abrasive particles, or any combination thereof. For example, the one or more middle abrasive regions may facilitate improved material removal, and the outermost and / or innermost abrasive regions and / or the total surface area of the non-abrasive portion may facilitate improved surface finishing (e.g., improved roughness).

[0183] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims. Reference herein to a material including one or more components may be interpreted to include at least one embodiment wherein the material consists essentially of the one or more components identified. The term “consisting essentially” will be interpreted to include a composition including those materials identified and excluding all other materials except in minority contents (e.g., impurity contents), which do not significantly alter the properties of the material. Additionally, or in the alternative, in certain non -limiting embodiments, any of the compositions identified herein may be essentially free of materials that are not expressly disclosed. The embodiments herein include a range of contents for certain components within a material, and it will be appreciated that the contents of the components within a given material total 100%.

[0184] The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Separate embodiments may also be provided in combination in a single embodiment, and conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, reference to values stated in ranges includes each and every value within that range. Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or another change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive.

Claims

WHAT IS CLAIMED IS:

1. An abrasive article, comprising a body comprising a plurality of abrasive regions comprising: a first abrasive region comprising first abrasive particles having a first average particle size; and a second concentric abrasive region comprising second abrasive particles having a second average particle size greater than the first average particle size, wherein the second abrasive region is spaced apart from the first abrasive region and comprises a smaller diameter than the first abrasive region.

2. The abrasive article of claim 1, wherein the body comprises an inner diameter (Di) defining a center region of the body and an outermost diameter (DI) defining an outer circumference of the body, wherein a percent surface area of the plurality of abrasive regions is at least 30% and not greater than 70% relative to a surface area of the body between Di and DI.

3. The abrasive article of claim 1 or 2, wherein the body comprises an annular non-abrasive portion between the first and second abrasive regions.

4. The abrasive article of any one of claims 1 to 3, wherein the plurality of abrasive regions comprise a third abrasive region concentric with the first and second abrasive regions, wherein the third abrasive region comprises a diameter smaller than the second abrasive region and third abrasive particles having a third average abrasive particle size smaller than the second average abrasive particle size.

5. The abrasive article of claim 4, wherein the body comprises an annular non-abrasive portion between the third and second abrasive regions.

6. The abrasive article of claim 4, wherein the first abrasive region, the second abrasive region, or the third abrasive region comprises a bond material comprising an organic material.

7. The abrasive article of claim 4, wherein the first abrasive particles, the second abrasive particles, or the third abrasive particles comprise a superabrasive material, an oxide, a carbide, a nitride, or any combination thereof.

8. The abrasive article of claim 4, wherein the first abrasive particles, the second abrasive particles, or the third abrasive particles comprise diamond, cBN, AI2O3, SiC, CeCh, or any combination thereof.

9. The abrasive article of any one of claims 1 to 3, wherein the first average particle size and the third average particle size is independently at least 1 micron and at most 70 microns.

10. The abrasive article of any one of claims 1 to 3, wherein the second average particle size is at least 10 microns and at most 300 microns.

11. The abrasive article of any one of claims 1 to 3, wherein a particle size ratio of the second average particle size to the first average particle size is greater than 1.

12. The abrasive article of claim 4, wherein a particle size ratio of the second average particle size to the third average particle size is greater than 1.

13. The abrasive article of claim 4, wherein the second average particle size is greater than the first average particle size and greater than the third average particle size.

14. The abrasive article of any one of claims 1 to 3, comprising a plurality of non-abrasive portions, wherein a total surface area of the plurality of non-abrasive portions is at least 50% of a total surface area of abrasive regions including the first and second abrasive regions.

15. The abrasive article of any one of claims 1 to 3, wherein the first abrasive region comprises a first radial thickness and the second abrasive region comprises a second radial thickness, wherein the first radial thickness is no less than the second radial thickness, and wherein the first and second radial thickness is independently at least 0.5% and at most 20% of an outer diameter of the body.

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