Low content PCBN rating with high metal content in binders

Abstract

A polycrystalline cubic boron nitride (PcBN) composition is provided that includes from about 60% to about 80% by volume, based on a total volume of the PcBN composition, of a cBN hard phase and from about 20% to about 40% by volume, based on a total volume of the PcBN composition, of a ceramic binder phase. The ceramic binder phase includes an AlN phase, an Al2O3 phase, at least one Co (x) W (y) B (z) phase, and substoichiometric (ss) titanium nitride (TiN), titanium carbonitride (TiCN), or a combination of TiN and TiCN. Further provided are related methods of making sintered PcBN briquettes, cutting tools, and briquettes made by using the PcBN compositions.

Description

Technical Field

[0001] The present disclosure relates to a polycrystalline cubic boron nitride (PcBN) composition having a high metal content ceramic binder. The present application further relates to related methods of making sintered PcBN compacts, cutting tools, and compacts containing the PcBN composition. Background Art

[0002] Cubic boron nitride (cBN) is a superabrasive hard material that is commonly associated with forming BN compacts for cutting and / or machining applications. Certain ceramic materials such as aluminum oxide (Al2O3), titanium nitride (TiN), titanium carbide (TiC), titanium carbonitride (TiCN), silicon nitride (Si3N4), etc. can be blended with cBN and further processed to improve the resistance of cBN to physical wear. However, such ceramic materials may not have sufficient fracture toughness, hardness and / or heat resistance to perform optimally when machining hard materials. In addition, existing PcBN-based compacts used to make cutting tools may still exhibit rapid wear and subsequent fracture.

[0003] In hard part turning applications, improved fracture toughness is required to prevent tool breakage, especially during interrupted cutting. Unreacted tungsten carbide (WC) particles produced during grinding may act as a propagation path for cracks. Conventional PcBN compacts containing more than one substoichiometric (ss) TiN, TiCN, AlN and Al2O3 typically have a sintered structure consisting of cBN grains, a ceramic binder phase consisting of TiN and TiCN grains, and Al2O3 embedded and anchored in the TiN and TiCN ceramic binder phase matrix. The Al2O3 can usually be found as isolated small dots in the TiN and TiCN ceramic binder phase matrix, or sometimes even the Al2O3 can be found adjacent to the cBN grains. In the microstructure, small white WC-Co islands or particles can also often be seen. This usually exists as a by-product of the grinding body and is called grinding debris in the field of metallurgy. Fracture toughness can be improved by converting WC grinding debris into a more tough phase through chemical reaction with the added Co. However, good vitrified bonding is critical to achieving consistent workable properties, which typically involves aggressive grinding of the vitrified bond to achieve the optimum target size.

[0004] To make PcBN material for tool manufacturing, cBN powder can be mixed with a ceramic binder matrix by forming a grinding slurry composition of the mixed ingredients with a grinding liquid (e.g., water, solvent, alcohol, or any mixture thereof. Next, the ingredients are blended, typically for several hours, in a ball mill, attritor, or planetary mill, for example, to form a grinding slurry blend.

[0005] The ground slurry blend may thereafter be subjected to, for example, vacuum drying, air drying, freeze drying, or spray drying, followed by subjecting the powder blend to a high pressure, high temperature (HPHT) sintering consolidation operation.

[0006] The core motivation of the grinding operation is to promote good vitrified binder distribution and good wettability between the cBN powder and vitrified binder powder components. Importantly, the adjustment of the mixed components by the grinding operation is the basis and key to strengthening the physical integrity of the ground components.

[0007] The desired good quality of ceramic binder distribution and wettability are important parameters for obtaining PcBN-based tools that do not break when, for example, cutting or machining ferrous metals. The downside is that, a non-negligible consequence is that if the standard and quality of ceramic binder distribution and wettability are poor, pores and cracks may undesirably appear in the final sintered PcBN body due to sensitivity, which is detrimental to the manufactured PcBN compact.

[0008] Therefore, in view of the above, there is a need for PcBN compositions with enhanced physical properties for making strong, high-quality tools with excellent performance for cutting and machining difficult-to-cut materials. Summary of the invention

[0009] A polycrystalline cubic boron nitride (PcBN) composition is provided. The PcBN composition comprises from about 60 volume % to about 80 volume % of a cBN hard phase based on the total volume of the PcBN composition. In addition, the composition has from about 20 volume % to about 40 volume % of a ceramic bonding phase based on the total volume of the PcBN composition. The ceramic bonding phase comprises an AlN phase, an Al2O3 phase, and at least one tough Co(x)W(y)B(z) phase.

[0010] Optionally, the ceramic binder phase comprises substoichiometric (ss) titanium nitride (TiN), titanium carbonitride (TiCN), or a combination thereof.

[0011] Optionally, the ceramic binder phase comprises substoichiometric or stoichiometric TiNO, TiCNO, or a combination thereof.

[0012] Optionally, the grain size of the cBN grains is in a range from about 3 microns to about 6 microns.

[0013] Optionally, the cBN grains have a grain size in a range from about 2 microns to about 4 microns.

[0014] Optionally, the grain size of the Co grains is in a range from about 0.1 microns to about 1 micron.

[0015] Optionally, the grain size of the tungsten carbide (WC) grains is in a range from about 0.1 microns to about 1 micron.

[0016] Optionally, (x) is 1, (y) is 2 and (z) is 2, and the at least one Co(x)W(y)B(z) tough phase comprises CoW2B2.

[0017] Optionally, (x) is 1, (y) is 1, and (z) is 1, and the at least one Co(x)W(y)B(z) tough phase comprises CoWB.

[0018] Optionally, based on the total weight of the PcBN composition, the amount of aluminum is in a range from about 3 wt % to about 6 wt %, the amount of cobalt is in a range from about 0.9 wt % to about 2.5 wt %, and the amount of tungsten is in a range from about 5 wt % to about 8 wt %.

[0019] A method for making a sintered polycrystalline cubic boron nitride (PcBN) compact is further provided, comprising grinding a powder mixture with a grinding body comprising at least tungsten carbide (WC) to form a powder blend and produce grinding debris, wherein the powder mixture comprises powders forming the following hard components: (i) from about 60 volume % to about 80 volume % of a cBN hard phase based on the total volume of the powder mixture and (ii) from about 20 volume % to about 40 volume % of a ceramic binder phase based on the total volume of the powder mixture. Next, the formed powder blend is dried. Finally, the components of the powder blend react under high pressure and high temperature (HPHT) conditions to form an AlN phase, an Al2O3 phase, and at least one tough Co(x)W(y)B(z) phase in the ceramic binder phase.

[0020] Optionally, drying the powder blend comprises vacuum drying, air drying, freeze drying, or spray drying.

[0021] Optionally, the grinding is performed using one or more solvents as a grinding slurry of the powder blend, the solvent comprising ethanol, methanol, isopropanol, butanol, cyclohexanol, acetone, hexane, heptane, toluene, water, or any combination thereof.

[0022] Optionally, the HPHT conditions include a pressure in a range from about 4 gigapascals (GPa) to about 8 GPa and a temperature in a range from about 1100°C to about 1800°C.

[0023] Optionally, the powder blend is loaded into a refractory metal cup after drying the powder blend.

[0024] A cutting tool is further provided, comprising the PcBN composition.

[0025] In addition, a compact is provided, which comprises the PcBN composition.

[0026] Other systems, methods, features and advantages will be or will become apparent to those skilled in the art upon review of the following drawings and detailed description. All such additional systems, methods, features and advantages are intended to be included in this specification, within the scope of the present disclosure, and protected by the appended claims. Nothing in this section should be construed as limiting these claims. Further aspects and advantages are discussed below in conjunction with the embodiments of the present disclosure. It should be understood that the foregoing general description and the following detailed description of the present disclosure are exemplary and illustrative, and are intended to provide further explanation of the claimed disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are included to provide a further understanding of the subject matter and are incorporated in and constitute a part of this specification, illustrate embodiments of the subject matter and together with the description serve to explain the principles of the disclosure.

[0028] Figure 1A An exemplary geometry of a sintered free-standing polycrystalline cubic boron nitride (PcBN) based compact including cBN particles is shown according to an exemplary embodiment of the present subject matter.

[0029] Figure 1B An exemplary geometry of a sintered supported polycrystalline cubic boron nitride (PcBN) based compact including cBN particles is shown according to an exemplary embodiment of the present subject matter.

[0030] Figure 2 is a flow chart illustrating various process steps for manufacturing a sintered polycrystalline cubic boron nitride (PcBN) based compact for a cutting tool according to an exemplary embodiment of the present subject matter.

[0031] Figure 3 An X-ray diffraction (XRD) spectrum showing the phases present in an exemplary polycrystalline cubic boron nitride (PcBN) system sintered compact with a titanium nitride (TiN) ceramic binder is shown.

[0032] Figure 4 An X-ray diffraction (XRD) spectrum showing the phases present in an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact having a substoichiometric (ss) titanium carbonitride (TiCN) ceramic binder is shown.

[0033] Figure 5A is a scanning electron microscope (SEM) image showing the microstructure of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with titanium nitride (TiN) ceramic binder at 2000X magnification.

[0034] Figure 5B is a scanning electron microscope (SEM) image showing the microstructure of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with titanium nitride (TiN) ceramic binder at 10,000 times magnification.

[0035] Fig. 6A is a scanning electron microscope (SEM) image of the microstructure of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with a substoichiometric (ss) titanium carbonitride (TiCN) ceramic binder shown at 2000X magnification.

[0036] Figure 6B is a scanning electron microscope (SEM) image showing the microstructure of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with a substoichiometric (ss) titanium carbonitride (TiCN) ceramic binder at 10,000X magnification.

[0037] Fig. 7A An X-ray diffraction (XRD) spectrum showing the phases present in Formulation A (65 vol % cBN, 22 vol %-23 vol % TiN, 5 wt % aluminum, 0.15 wt % cobalt, 2.6 wt % tungsten) of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with titanium nitride (TiN) ceramic binder is shown.

[0038] Figure 7B An X-ray diffraction (XRD) spectrum showing the phases present in Formulation B (65 vol % cBN, 21 vol %-22 vol % TiN, 5 wt % aluminum, 1.4 wt % cobalt, 6.4 wt % tungsten) of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with titanium nitride (TiN) ceramic binder is shown.

[0039] Figure 7C An X-ray diffraction (XRD) spectrum showing the phases present in Formulation C (70 vol % cBN, 22 vol %-23 vol % TiN, 3.8 wt % aluminum, 0.2 wt % cobalt, 2.6 wt % tungsten) of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with titanium nitride (TiN) ceramic binder is shown.

[0040] Fig.7DAn X-ray diffraction (XRD) spectrum showing the phases present in Formulation D (72 vol % cBN, 21 vol %-22 vol % TiN, 4.1 wt % aluminum, 1.1 wt % cobalt, 5.2 wt % tungsten) of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with titanium nitride (TiN) ceramic binder is shown.

[0041] Fig. 7E An X-ray diffraction (XRD) spectrum showing the phases present in Formulation E (62 vol % cBN, 22-23 vol % TiCN, 4.4 wt % aluminum, 0.2 wt % cobalt, 2.7 wt % tungsten) of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with a substoichiometric (ss) titanium carbonitride (TiCN) ceramic binder is shown.

[0042] Figure 7F An X-ray diffraction (XRD) spectrum showing the phases present in Formulation F (70 vol % cBN, 21 vol %-22 vol % TiCN, 3.3 wt % aluminum, 1.1 wt % cobalt, 5.1 wt % tungsten) of an exemplary polycrystalline cubic boron nitride (PcBN) based sintered compact with a substoichiometric (ss) titanium carbonitride (TiCN) ceramic binder is shown. DETAILED DESCRIPTION

[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the presently described subject matter belongs.

[0044] Where a numerical range (e.g., a concentration range, a percentage range, or a ratio range) is provided, it is understood that each intervening value (to the nearest tenth of the unit of the lower limit unless the context clearly dictates otherwise) between the upper and lower limits of that range and any other stated value or intervening value in that stated range is encompassed within the subject matter. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and such embodiments are also encompassed within the subject matter, subject to any specifically excluded limits in the stated range. Where the stated range includes one or both of the limits, ranges excluding one or both of those included limits are also encompassed within the described subject matter.

[0045] The following definitions set forth the parameters of the described subject matter.

[0046] As used in the present disclosure, the term "mill debris" generally refers to WC material formed from at least the grinding media or the lining of the mill, which is caused by friction between the cBN abrasive particles, the grinding body and the lining of the mill. There are many factors that determine the amount of mill debris that may be generated, including at least the grinding media volume and density, the jar size, and the grinding slurry viscosity. The mill debris generally increases in proportion to the grinding time, the cBN particle size, and the grinding speed. Since cBN particles are much harder and more rigid than sintered WC particles, a large amount of mill debris may naturally be generated when cBN particles are present in the mill. Since WC particles are added to the blend for further processing by scratching, scraping or wearing away WC particles from the sintered WC grinding media, one method of determining the WC particle size obtained from the mill debris is to use a scanning electron microscope (SEM) image. This is actually done by measuring the so-called Feret diameter. Those of ordinary skill in the art will know that in order to determine the Feret diameter, a rectangle is first drawn that completely surrounds the WC particle. The length of the long side of the rectangle is the maximum Feret diameter. The length of the short side of the rectangle is the minimum Feret diameter. Therefore, the average maximum Feret diameter and the average minimum Feret diameter of the WC particles obtained from the grinding debris can be calculated from multiple SEM images to ultimately determine the WC particle size obtained from the grinding debris.

[0047] As used in the present disclosure, the term "PcBN compact" refers to a sintered product consisting of a cumulative mass of a plurality of wear-resistant superabrasive cBN particles compacted and bonded together in a self-bonded relationship, by a bonding medium, or by a combination thereof. As used in the present disclosure, the term "PcBN composite compact" refers to a PcBN compact supported on a sintered WC substrate.

[0048] As used in this disclosure, the term "particle" refers to one or more discrete bodies. As used in this disclosure, the term "particle" is also considered a crystal or a grain.

[0049] As used in the present disclosure, unless otherwise specifically stated, the term "volume %" or "weight %" refers to a given volume percentage or weight percentage based on (I) the total volume or total weight of the PcBN composition, (II) the total volume of the powder mixture, or (III) the total weight of the PcBN compact. When "volume %" or "weight %" is mentioned in the present disclosure or the appended claims, it will also be clearly mentioned whether it refers to a given volume percentage of (I), (II) or (III) in each given specific scenario.

[0050] Grades can be classified, for example, based on grain size. Different types of grades for different types of materials have been defined as nano, ultrafine, submicron, fine, medium, medium-coarse, coarse, and ultra-coarse. As used in this disclosure, the term (I) "nano" is defined as a component of a CBN composition having a grain size of less than about 0.2 microns, (II) "ultrafine" is defined as a component of a CBN composition having a grain size of from about 0.2 microns to about 0.5 microns, (III) "submicron" is defined as a component of a CBN composition having a grain size of from about 0.5 microns to about 0.9 microns, (IV) "fine" is defined as a component of a CBN composition having a grain size of from about 1.0 microns to about 1.3 microns, (V) "intermediate" is defined as a component of a CBN composition having a grain size of from about 1.4 microns to about 2.0 microns, (VI) "medium-coarse" is defined as a component of a CBN composition having a grain size of from about 2.1 microns to about 3.4 microns, (VII) "Coarse grade" is defined as a CBN composition having a grain size from about 3.5 microns to about 5.0 microns, and (VIII) "Extra coarse grade" is defined as a CBN composition having a grain size greater than about 5.0 microns.

[0051] As used in the present disclosure, the term "superabrasive superhard material" or simply "superabrasive material" refers to an abrasive that exhibits excellent hardness and wear resistance, which can exhibit a Knoop indentation hardness of more than 2000, as shown below but not limited to: crystalline diamond, polycrystalline diamond (PCD), thermally stable polycrystalline diamond, chemical vapor deposition (CVD) diamond, metal matrix diamond composite, ceramic matrix diamond composite, nanodiamond, cubic boron nitride (cBN), polycrystalline cubic boron nitride (PcBN) or any such combination thereof. As used herein, the term "abrasive" refers to any material used to grind away softer materials.

[0052] As used in the present disclosure, the term "about" refers to plus or minus 5% of the numerical value of the numbers used in the claims and the present disclosure. Therefore, "about" can be used to provide flexibility to numerical range endpoints, wherein a given value can be "above" or "below" the given value. Thus, for example, a value of 50% may be intended to encompass a range that may be defined by, for example, the following ranges: 47.5%-52.25%, 47.5%-52.5%, 47.75%-50%, 50%-52.5%, 48%-48.5%, 48%-48.75%, 48%-49%, 48%-49.5%, 48%-49.75%, 48%-50%, 48%-50.25%, 48%-50.5%, 48%-50.75%, 48%-51%, 48%-51.5%, 48%-51.75%, 48%-52%, 48%-52.25%, 48%-52. ... 52.5%, 48.25%-48.5%, 48.25%-48.75%, 48.25%-49%, 48.25%-49.5%, 48.25%-49.75%, 48.25%-50%, 48.25%-50.25%, 48.25%-50.5%, 48.25%-50.75%, 48.25%-51%, 48.25%-51.25%, 48.25%-51.5%, 48.25%-51.75%, 48.25%-52%, 48.25%-52.25%, 48.25%-52.5%, 48.5%-48.75%, 48.5%-49%, 48.5%-49.5%, 48.5%-49.75%, 48.5%-50%, 48.5%-50.25%, 48.5%-50.5%, 48.5%-50.75%, 48.5%-51%, 48.5%-51.25%, 48.5%-51.5%, 48.5%-51.75%, 48.5%-52%, 48.5%-52.25%, 48.5%-52.5%, 49%-49.25%, 49%-49.5%, 49%-49.75%, 49%-50%, 49%-50.25%, 49%-50.5% , 49%-50.75%, 49%-51%, 49%-51.25%, 49%-51.5%, 49%-51.75%, 49%-52%, 49%-52.25%, 49%-52.5%, 49.5%-49.75%, 49.5%-50%, 49.5%-50.25%, 49.5%-50.5%, 49.5%-50.75%, 49.5%-51%, 49.5%-51.5%, 49.5%-51.75%, 49.5%-52%, 49.5%-52.25%, 49.5%-52.5%, 49.75%-50%, 49.75%-50.25%, 49.75%-50.5%, 49.75%-50.75%, 49.75%-51%, 49.75%-51.25%, 49.75%-51.5%, 49.75%-51.75%, 49.75%-52%, 49.75%-52.25%, 49.75%-52.5%, 50%-50.25%, 50%-50.5%, 50%-50.75%, 50%-51%, 50%-51.25%, 50%-51.5%, 50%-52%, 50%-52.25%, 50%-52.5%, etc. .

[0053] Wherever used throughout this disclosure, the term "generally" has the meaning of "typically" or "closely" or "around or in the vicinity of."

[0054] As used herein, the term "substantially" refers to the complete or nearly complete extent or degree of an action, characteristic, performance, state, structure, item, or result.

[0055] As used herein, "spherical" refers to grains having a substantially "round" shape.

[0056] As used in this disclosure, the term "fracture toughness" refers to the ability of a material to resist fracture and / or crack propagation.

[0057] As used in the present disclosure, the term "high pressure high temperature (HPHT) sintering" refers to a process in which heating is generally performed at a pressure ranging from about 4 gigapascals (GPa) to about 8 GPa to minimize the surface of the cBN-based particle system, which is associated with the generation of bonding between adjacent small cBN particles or cBN particles and subsequent shrinkage of the aggregated cBN particles or cBN particles. The small cBN particles are compacted and formed into a dense mass by heating under pressure. The atoms in the small cBN particles diffuse across the boundaries of the cBN particles, whereby the small cBN particles fuse together to produce a solid dense mass.

[0058] Polycrystalline cubic boron nitride (PcBN) compositions

[0059] The present disclosure is based on the premise of presenting a polycrystalline cubic boron nitride (PcBN) composition wherein the cBN hard phase reacts with high metal content levels of aluminum (Al), cobalt (Co) and tungsten (W) present in a ceramic binder phase. The ceramic binder is composed of substoichiometric (ss) titanium nitride (TiN), titanium carbonitride (TiCN) or a combination thereof, i.e., the N / Ti ratio or CN / Ti ratio is significantly less than 1. The ceramic binder in the PcBN composition exhibits increased fracture toughness, which is caused by the reaction of the Co in the ceramic binder with the added grinding debris having at least tungsten carbide (WC) particles therein. Without wishing to be bound by theory, it is hypothesized that the unreacted WC particles (i.e., grinding debris) generated during grinding act as crack propagation paths. The reader will appreciate that the advantages over simply adding a WC-containing powder are at least manifold. First, the grinding debris is evenly dispersed throughout the blend to which the grinding debris is added. Second, the grinding debris is very fine, typically less than about 1 micron. In fact, sourcing, safely handling and dispersing submicron powders in this regard is a rather challenging task, and the present subject matter avoids such challenges. During high pressure and high temperature (HPHT) sintering, the Co in the ceramic binder reacts with the WC particles obtained from the grinding chips, as described in paragraph

[0046] , and with the boron in the cBN, thereby forming at least one discrete tough Co(x)W(y)B(z) phase in the ceramic binder, wherein the cobalt no longer acts as a binder, but rather as a hard phase. In other words, the cobalt in the at least one tough Co(x)W(y)B(z) phase is no longer metallic. In one example, (x) is 1, (y) is 2 and (z) is 2, and the at least one Co(x)W(y)B(z) tough phase comprises CoW2B2. In another example, (x) is 1, (y) is 1 and (z) is 1, and the at least one Co(x)W(y)B(z) tough phase comprises CoWB. The independent phases further formed in the ceramic binder are at least AlN phase and Al2O3 phase. The grinding body is composed of 94 wt% WC and 6 wt% Co binder. The grinding chips have the same composition as the grinding body, namely 94 wt% WC and 6 wt% Co. However, the cobalt content of 6 wt% is usually not enough to form the above-mentioned tough CoW2B2 phase. Therefore, additional metallic cobalt is usually added to the grinding slurry. The carbon removed from the WC is instead integrated into the TiN / TiCN matrix of the ceramic binder.

[0060] Based on the total volume of the PcBN composition, the cBN hard phase can generally be present from about 60 volume % to about 80 volume %. In some examples, based on the total volume of the PcBN composition, the cBN hard phase is present from about 62 volume % to about 80 volume %. In other examples, based on the total volume of the PcBN composition, the cBN hard phase is present from about 65 volume % to about 80 volume %. In yet other examples, based on the total volume of the PcBN composition, the cBN hard phase is present from about 67 volume % to about 80 volume %. In still other examples, based on the total volume of the PcBN composition, the cBN hard phase is present from about 69 volume % to about 80 volume %. In even other examples, based on the total volume of the PcBN composition, the cBN hard phase is present from about 71 volume % to about 80 volume %. In further other examples, the cBN hard phase is present from about 73 volume % to about 80 volume % based on the total volume of the PcBN composition. In other embodiments, the cBN hard phase is present from about 75 volume % to about 80 volume % based on the total volume of the PcBN composition. In still other embodiments, the cBN hard phase is present from about 77 volume % to about 80 volume % based on the total volume of the PcBN composition. In even other embodiments, the cBN hard phase is present from about 78 volume % to about 80 volume % based on the total volume of the PcBN composition.

[0061] The cBN hard phase may also be present in an amount from about 60 vol % to about 62 vol %, 60 vol % to about 65 vol %, from about 62 vol % to about 65 vol %, from about 65 vol % to about 67 vol %, from about 60 vol % to about 67 wt %, from about 60 vol % to about 70 wt %, from about 60 vol % to about 72 wt %, from about 60 vol % to about 75 wt %, from about 67 vol % to about 69 vol %, from about 69 vol % to about 71 vol %, from about 71 vol % to about 73 vol %, from about 67 vol % to about 73 vol %, from about 67 vol % to about 75 vol %, from about 67 vol % to about 77 vol %, from about 70 vol % to about 75 vol %, from about 70 vol % to about 77 vol %, from about 70 vol % to about 79 vol %, from about 73 vol % to about 75 vol %, from about 73 vol % to about 77 vol %, or from about 75 vol % to about 77 vol %, based on the total volume of the PcBN composition.

[0062] The ceramic binder described in the present disclosure may generally be composed of a carbide, boride, nitride, carbonitride or oxide of at least one metal selected from Group 4, Group 5 and Group 6 of the periodic table, or any combination thereof.

[0063] In one particular embodiment, the ceramic binder is composed of substoichiometric (ss) TiN, TiCN, or a combination thereof. Without wishing to be bound by any particular theory, it is believed that titanium-containing binders (e.g., TiN, TiCN) can function as ceramic binders and generally have a similar effect on improving the cutting ability of tools formed from the compact. In still other embodiments, the ceramic binder is composed of substoichiometric or stoichiometric TiNO, TiCNO, or a combination thereof.

[0064] The ceramic binder and grain growth inhibitor during sintering such as vanadium carbide (VC), chromium carbide (Cr3C2), tantalum carbide (TaC), titanium carbide (TiC), zirconium carbide (ZrC), niobium carbide (NbC) can be present in the PcBN composition in any possible combination as long as it is not inconsistent and incompatible with the purpose of the present subject matter.

[0065] Based on the total volume of the PcBN composition, the ceramic bonding phase can generally be present from about 20 volume % to about 40 volume %. In some examples, based on the total volume of the PcBN composition, the ceramic bonding phase is present from about 22 volume % to about 40 volume %. In other examples, based on the total volume of the PcBN composition, the ceramic bonding phase is present from about 24 volume % to about 40 volume %. In yet other examples, based on the total volume of the PcBN composition, the ceramic bonding phase is present from about 26 volume % to about 40 volume %. In still other examples, based on the total volume of the PcBN composition, the ceramic bonding phase is present from about 28 volume % to about 40 volume %. In further other examples, based on the total volume of the PcBN composition, the ceramic bonding phase is present from about 30 volume % to about 40 volume %. In even other examples, based on the total volume of the PcBN composition, the ceramic bonding phase is present from about 32 volume % to about 40 volume %. In other embodiments, the ceramic bonding phase is present at from about 34 volume % to about 40 volume % based on the total volume of the PcBN composition. In still other embodiments, the ceramic bonding phase is present at from about 36 volume % to about 40 volume % based on the total volume of the PcBN composition. In yet other embodiments, the ceramic bonding phase is present at from about 38 volume % to about 40 volume % based on the total volume of the PcBN composition.

[0066] The ceramic bonding phase may also be present in an amount from about 20% to about 22% by volume, from about 22% to about 24% by volume, from about 24% to about 26% by volume, from about 26% to about 28% by volume, from about 20% to about 25% by volume, from about 20% to about 26% by volume, from about 20% to about 27% by volume, from about 20% to about 28% by volume, from about 20% to about 29% by volume, from about 20% to about 30% by volume, from about 25% to about 30% by volume, based on the total volume of the PcBN composition. %, from about 26% to about 30% by volume, from about 27% to about 30% by volume, from about 28% to about 30% by volume, from about 29% to about 30% by volume, from about 30% to about 32% by volume, from about 30% to about 35% by volume, from about 30% to about 37% by volume, from about 32% to about 34% by volume, from about 32% to about 35% by volume, from about 34% to about 36% by volume, from about 36% to about 38% by volume, from about 35% to about 40% by volume, or from about 38% to about 40% by volume.

[0067] The grain growth inhibitor may generally be present in an amount of from about 1 vol % to about 2 vol %, 1 vol % to about 3 vol %, from about 2 vol % to about 5 vol %, from about 5 vol % to about 7 vol %, from about 3 vol % to about 7 vol %, from about 7 vol % to about 10 vol %, about 10.1 vol %, about 10.2 vol %, about 10.3 vol %, about 10.4 vol %, about 10.5 vol %, about 10.6 vol %, about 10.7 vol %, about 10.8 vol %, about 10.9 vol %, about 11.1 vol %, about 11.2 vol %, about 11.3 vol %, about 11.4 vol %, about 11.5 vol %, about 11.6 vol %, about 11.7 vol %, about 11.8 vol %, about 1 ... .8 volume %, about 10.9 volume %, from about 7 volume % to about 20 volume %, from about 10 volume % to about 20 volume %, from about 12 volume % to about 20 volume %, from about 15 volume % to about 20 volume %, from about 17 volume % to about 20 volume %, from about 10 volume % to about 12 volume %, from about 10 volume % to about 15 volume %, from about 10 volume % to about 17 volume %, from about 10 volume % to about 20 volume %, from about 15 volume % to about 20 volume %, or from about 17 volume % to about 20 volume %.

[0068] The grain size of the cBN grains may generally be in the range of from about 2 microns to about 4 microns, or the grain size spans from about 3 microns to about 6 microns. In some examples, the grain size of the cBN grains is from about 2.5 microns to about 4 microns. In other examples, the grain size of the cBN grains is from about 3 microns to about 4 microns. In still other examples, the grain size of the cBN grains is from about 3.5 microns to about 4 microns. In yet other examples, the grain size of the cBN grains is from about 3.5 microns to about 6 microns. In further other examples, the grain size of the cBN grains is from about 4 microns to about 6 microns. In even other examples, the grain size of the cBN grains is from about 4.5 microns to about 6 microns. In even further other examples, the grain size of the cBN grains is from about 5 microns to about 6 microns. In other embodiments, the grain size of the cBN grains is from about 5.5 microns to about 6 microns.

[0069] The grain size of the cBN grains may also be from about 2 microns to about 2.25 microns, from about 2 microns to about 2.5 microns, from about 2 microns to about 2.75 microns, from about 2 microns to about 3 microns, from about 2 microns to about 3.25 microns, from about 2 microns to about 3.5 microns, from about 2 microns to about 3.75 microns, from about 2.5 microns to about 2.75 microns, from about 2.5 microns to about 3 microns, from about 2.5 microns to about 3.25 microns, from about 2.5 microns to about 3.5 microns, from about 2.5 microns to about 3.75 microns, from about 2.25 microns to about 2.5 microns, from about 2.25 microns to about 2.75 microns, micrometers to about 3 micrometers, from about 2.25 micrometers to about 3.25 micrometers, from about 2.25 micrometers to about 3.5 micrometers, from about 2.25 micrometers to about 3.75 micrometers, from about 2.25 micrometers to about 4 micrometers, from about 2.5 micrometers to about 3.25 micrometers, from about 2.75 micrometers to about 3.25 micrometers, from about 2.75 micrometers to about 3.5 micrometers, from about 3 micrometers to about 3.25 micrometers, from about 3 micrometers to about 3.5 micrometers, from about 2.75 micrometers to about 3.75 micrometers, from about 3 micrometers to about 3.5 micrometers, from about 3 micrometers to about 3.75 micrometers, from about 2.5 micrometers to about 4 micrometers, from about 2.75 micrometers to about 4 micrometers, from about 3.2 5 microns to about 4 microns, from about 3.5 microns to about 4 microns, from about 3.75 microns to about 4 microns, from about 3 microns to about 4.25 microns, from about 3 microns to about 4.5 microns, from about 3 microns to about 4.75 microns, from about 3 microns to about 5 microns, from about 3 microns to about 5.25 microns, from about 3 microns to about 5.5 microns, from about 3 microns to about 5.75 microns, from about 4 microns to about 4.25 microns, from about 4 microns to about 4.5 microns, from about 4 microns to about 4.75 microns, from about 4 microns to about 5 microns, from about 4 microns to about 5.25 microns, from about 4 microns to about 5.5 microns, from about 4 microns to about 5.75 microns, from about 4 microns to about 4.25 microns, from about 4 microns to about 4.5 microns, from about 4 microns to about 4.75 microns, from about 4 microns to about 5 microns, from about 4 microns to about 5. From about 4.5 microns to about 4.75 microns, from about 4.5 microns to about 5 microns, from about 4.5 microns to about 5.25 microns, from about 4.5 microns to about 5.5 microns, from about 4.5 microns to about 5.75 microns, from about 4.5 microns to about 6 microns, from about 4.75 microns to about 5 microns, from about 4.75 microns to about 5.25 microns, from about 4.75 microns to about 5.5 microns, from about 4.75 microns to about 5.75 microns, from about 4.75 microns to about 6 microns, from about 5 microns to about 5.25 microns, from about 5.25 microns to about 5.5 microns, from about 5 microns to about 5.5 microns, or from about 5 microns to about 5.75 microns.

[0070] The grain size of the WC grains in the grinding debris may generally be in the range of from about 0.1 micrometer to about 1 micrometer. In certain specific embodiments, the grain size of the WC grains is from about 0.1 micrometer to about 0.2 micrometer, from about 0.2 micrometer to about 0.3 micrometer, from about 0.3 micrometer to about 0.4 micrometer, from about 0.1 micrometer to about 0.4 micrometer, 0.1 micrometer to about 0.5 micrometer, 0.2 micrometer to about 0.5 micrometer, 0.3 micrometer to about 0.5 micrometer, from about 0.4 micrometer to about 0.5 micrometer, from about 0.5 micrometer to about 0.6 micrometer, from about 0.5 micrometer to about 0.7 micrometer, from about 0.5 micrometer to about 0.8 micrometer, from about 0.5 micrometer to about 0.9 micrometer, from about 0.5 micrometer to about 1.0 micrometer, from about 0.6 micrometer To about 0.7 micron, from about 0.4 micron to about 0.7 micron, from about 0.4 micron to about 0.8 micron, from about 0.4 micron to about 0.9 micron, from about 0.4 micron to about 1.0 micron, from about 0.7 micron to about 0.8 micron, from about 0.8 micron to about 0.9 micron, from about 0.1 micron to about 1.0 micron, from about 0.2 micron to about 1.0 micron, from about 0.3 micron to about 1.0 micron, from about 0.4 micron to about 1.0 micron, from about 0.6 micron to about 1.0 micron, from about 0.7 micron to about 1.0 micron, from about 0.8 micron to about 1.0 micron, or from about 0.9 micron to about 1.0 micron.

[0071] The grain size of the Co grains may generally be in the range of from about 0.1 micrometer to about 1 micrometer. In certain specific embodiments, the grain size of the Co grains is from about 0.1 micrometer to about 0.2 micrometer, from about 0.2 micrometer to about 0.3 micrometer, from about 0.3 micrometer to about 0.4 micrometer, from about 0.1 micrometer to about 0.4 micrometer, from about 0.1 micrometer to about 0.5 micrometer, from about 0.2 micrometer to about 0.5 micrometer, from about 0.3 micrometer to about 0.5 micrometer, from about 0.4 micrometer to about 0.5 micrometer, from about 0.5 micrometer to about 0.6 micrometer, from about 0.5 micrometer to about 0.7 micrometer, from about 0.5 micrometer to about 0.8 micrometer, from about 0.5 micrometer to about 0.9 micrometer, from about 0.5 micrometer to about 1.0 micrometer, from about 0. 6 microns to about 0.7 microns, from about 0.4 microns to about 0.7 microns, from about 0.4 microns to about 0.8 microns, from about 0.4 microns to about 0.9 microns, from about 0.4 microns to about 1.0 microns, from about 0.7 microns to about 0.8 microns, from about 0.8 microns to about 0.9 microns, from about 0.1 microns to about 1.0 microns, from about 0.2 microns to about 1.0 microns, from about 0.3 microns to about 1.0 microns, from about 0.4 microns to about 1.0 microns, from about 0.6 microns to about 1.0 microns, from about 0.7 microns to about 1.0 microns, from about 0.8 microns to about 1.0 microns, or from about 0.9 microns to about 1.0 microns.

[0072] To determine a specific cBN grain size or a specific Co grain size, a person skilled in the art can generally use the following techniques: techniques using dynamic digital image analysis (DIA), static laser light scattering (SLS) (also known as laser diffraction), or visual measurements by electron microscopy (techniques known as image analysis and light shielding). Each method covers a range of characteristic sizes that can be measured. These ranges overlap in part. However, the results of measuring the same sample may be different, which depends entirely on the specific method used. A person skilled in the art who wants to determine the grain size or particle size distribution will readily know how each of the mentioned methods is generally performed and practiced. Thus, the reader is referred to, for example, (i) "Comparison of Methods. Dynamic Digital Image Analysis, Laser Diffraction, Sieve Analysis", Retsch Technology, Inc. and (ii) the scientific publication by Kelly et al., "Graphical comparison of image analysis and laser diffraction particle size analysis data obtained from the measurements of nonspherical particle systems", AAPS PharmSciTech. 2006 Aug 18; Vol. 7(3):69, for further insight into the various procedures and methods, all of which are incorporated herein by reference in their entirety.

[0073] Ideally, a compact containing a supporting sintered WC matrix is ​​referred to in the metallurgical art as a supported compact. Alternatively, the manufacturing process may also be carried out without the presence of a supporting sintered WC matrix, in which case the recovered compact is referred to in the metallurgical art as an unsupported compact. Figure 1A and Figure 1B Exemplary geometries of an unsupported compact 10 and a supported compact 20 are shown, respectively. Figure 1BThe support compact 20 shown in FIG. 1 generally comprises a body 30 composed of sintered cBN particles supported on a sintered WC matrix 35, and the body 30 is further anchored in a matrix of a ceramic binder material bonded by a transition interface. Optionally, they can be manufactured as a freestanding / unsupported PCBN material. The Co in the ceramic binder reacts with the WC present in the added grinding chips (which have at least WC) and reacts with the boron in the body 30, thereby forming at least one discrete tough Co(x)W(y)B(z) phase during the HPHT sintering consolidation operation, as further described below in paragraphs

[0079] to

[0080] . In one example, (x) is 1, (y) is 2 and (z) is 2, and the at least one Co(x)W(y)B(z) tough phase comprises CoW2B2. In another example, (x) is 1, (y) is 1, and (z) is 1, and the at least one Co(x)W(y)B(z) tough phase comprises CoWB. The independent phases further formed in the ceramic binder are at least an AlN phase and an Al2O3 phase. Based on the total weight of the PcBN compact, the amount of aluminum may be in the range of from about 3 wt% to about 6 wt%, the amount of cobalt may be in the range of from about 0.9 wt% to about 2.5 wt%, and the amount of tungsten may be in the range of from about 5 wt% to about 8 wt%. Figure 1A The unsupported compact 10 shown in FIG. 1 also contains a body 15 comprising sintered cBN particles. Figure 1A The unsupported block 10 and Figure 1B In both of the support compacts 20 depicted in FIG, the sintered bodies 15, 30 are composed of a plurality of wear-resistant cBN particles that are compacted and bonded together. The plurality of cBN particles each contain a plurality of sub-grains. Each sub-grain can typically show a size ranging from less than about 1 micron to about 2 microns or from about 0.1 microns to about 1.5 microns, typically measured by a MicroTrac particle characterization system. A typical exemplary discrete cBN particle having a particle size of about 1 micron to about 2 microns can, for example, contain from about 10 to about 5000 sub-grains.

[0074] Method for manufacturing sintered polycrystalline cubic boron nitride (PcBN) compact

[0075] Now turn your attention to Figure 2 , which shows a flow chart 200 depicting various process steps for manufacturing a PcBN compact for a tool according to an exemplary embodiment of the present subject matter.

[0076] Exemplary process 200 includes, for example, mixing, in step 202, a powder that forms a hard component with: (i) from about 60 volume % to about 80 volume % of a cBN hard phase based on the total volume of the powder mixture, and (ii) from about 20 volume % to about 40 volume % of a ceramic binder phase based on the total volume of the formed powder mixture, with a grinding body containing at least tungsten carbide (WC).

[0077] In step 204, the desired particle size of the cBN powder and the ceramic binder powder can be produced by subjecting the powder mixture to a grinding process, typically for several hours (e.g., 8, 16, 32, 64 hours), typically at ambient conditions (i.e., in a ball mill, attritor, or planetary mill, 25° C., 298.15 K, and a pressure of 101.325 kPa), wherein the ceramic binder has a metal binder therein, to form a powder blend and produce grinding debris having at least WC therein. The general purpose of blending by grinding operations is to promote good ceramic binder distribution and good wettability between the components of the powder mixture of the cBN and the ceramic binder, thereby forming the powder blend. In some cases, the cBN powder and the ceramic binder powder can be crushed or otherwise pulverized prior to grinding with the metal binder.

[0078] It is obvious to those skilled in the art that the grinding in step 204 is performed by first adding a grinding liquid to the cBN and the ceramic binder powder to form a grinding slurry. The grinding liquid can be water, an alcohol such as but not limited to ethanol, methanol, isopropanol, butanol, cyclohexanol, an organic solvent such as hexane, heptane, acetone, toluene, etc., or a mixture of water, alcohol, a mixture of an alcohol and a solvent, or any combination thereof.

[0079] Process 200 may include a drying operation in step 206. The milled powder blend may be dried using any conventional technique such as vacuum drying, air drying, freeze drying, or spray drying to substantially remove the solvent from the milled slurry by evaporation.

[0080] The process 200 may optionally further include loading the dried powder blend into a refractory metal cup at step 208 .

[0081] Next, the process 200 may include a HPHT sintering consolidation operation in step 210. The refractory metal cup containing the dried powder blend may be placed in a HPHT unit and HPHT sintering conditions may be applied to form a sintered PcBN compact for a tool disclosed herein. Step 210 may include sintering at a pressure and temperature ranging from about 4 gigapascals (GPa) to about 8 GPa, from about 5 GPa to about 8 GPa, from about 6 GPa to about 8 GPa, from about 7 GPa to about 8 GPa, from about 5 GPa to about 6 GPa, from about 5 GPa to about 7 GPa, or from about 6 GPa to about 7 GPa. GPa, the temperature ranges from about 1100°C to about 1500°C, from about 1100°C to about 1600°C, from about 1100°C to about 1700°C, from about 1100°C to about 1800°C, from about 1200°C to about 1500°C, from about 1200°C to about 1600°C, from about 1200°C to about 1700°C, from about 1200°C to about 1800°C, from about 1300°C to about 1400°C, from about 1300°C to about 1 From about 1500°C to about 1600°C, from about 1300°C to about 1700°C, from about 1300°C to about 1800°C, from about 1400°C to about 1500°C, from about 1400°C to about 1600°C, from about 1500°C to about 1600°C, from about 1500°C to about 1700°C, from about 1500°C to about 1800°C, from about 1600°C to about 1800°C, or from about 1700°C to about 1800°C.

[0082] The specific sintering pressure and temperature range are selected in a manner that will sufficiently melt the ceramic binder phase. The sintered PcBN compact may contain cBN grains uniformly or substantially uniformly dispersed in the ceramic binder phase. During the HPHT sintering consolidation process, the Co in the ceramic binder in the body 30 reacts with the WC particles and boron obtained from the grinding debris as previously described in paragraph

[0046] , thereby forming at least one discrete tough Co(x)W(y)B(z) phase. In one example, (x) is 1, (y) is 2, and (z) is 2, and the at least one Co(x)W(y)B(z) tough phase comprises CoW2B2. In another example, (x) is 1, (y) is 1, and (z) is 1, and the at least one Co(x)W(y)B(z) tough phase comprises CoWB. The independent phases further formed in the ceramic binder are at least AlN phase and Al2O3 phase.

[0083] In practice, those skilled in the art will readily know how to generally perform a HPHT sintering consolidation procedure to form cBN. Therefore, the reader may refer to, for example, U.S. Pat. No. 5,512,235 B2; U.S. Pat. No. 10,196,314 B2 and U.S. Pat. No. 10,252,947 B2 for further information on various HPHT sintering procedures, techniques and methods, all of which are incorporated herein by reference in their entirety.

[0084] After the HPHT sintering consolidation operation is completed in step 210, the resulting PcBN compact can be machined to form a disk of the PcBN compact. Machining can be performed via a process generally known in the art to form a suitable cutting tool. Here, machining can suitably include electrical discharge machining (EDM), electrical discharge grinding (EDG), or other processes that form the PcBN compact into a desired shape. Suitable shapes can, for example, include a triangle of 80° to 120°, thereby advantageously forming a tip for various cutting and machining applications after the disk is brazed on the carbide tool body.

[0085] The blocks formed by using the PcBN compositions described herein can be advantageously used to manufacture cutting tools. In some embodiments, the PcBN blocks manufactured using the PcBN compositions can be used to form cutting blade blanks that are generally used for machining metals and metal alloys. Therefore, the PcBN blocks formed according to process 200 can be used for machining, for example, metals or metal alloys that are difficult to cut. For example, in this scenario, the PcBN blocks formed according to process 200 can be formed into cutting tools for machining high-strength alloys. In other embodiments, the PcBN blocks can be used to manufacture intermittent cutting tools, such as veining end mills and / or milling inserts.

[0086] In summary, PcBN compacts formed using the PcBN compositions described herein can impart enhanced wear resistance and excellent abrasion resistance, thereby significantly improving cutting and machining performance and thus ultimately leading to a valuable increase in the service life of the cutting tools so manufactured.

[0087] Example

[0088] The following examples are put forward to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the subject matter, and are not intended to limit the scope of what the inventors regard as their disclosure, nor are they intended to represent that the experiments below are all or the only experiments performed. Efforts have been made to ensure accuracy of the numbers used, but some experimental errors and deviations should be accounted for.

[0089] Example 1

[0090] Phase identification was performed by X-ray diffraction (XRD) spectra and scanning electron microscopy (SEM) image analysis of sintered polycrystalline cubic boron nitride (PCBN) based compact materials.

[0091] X-ray diffraction (XRD) spectra were performed on the sintered PcBN-based compact materials disclosed herein to identify the different phases present in the PcBN-based compact materials. Figure 3 and Figure 4 Such exemplary XRD spectra are shown respectively for materials having: (i) TiN ceramic binder (exemplary compact material 1), or (ii) substoichiometric (ss) TiCN ceramic binder (exemplary compact material 2). These materials are made according to standard process procedures for making PcBN-based compacts. TiN and ssTiCN ceramic binder materials and cBN are mixed in ethanol to first form a grinding slurry, which is then typically ground in a grinding mill for at least 8 hours to ensure uniform distribution of cBN while producing the desired level of sintered WC / Co grinding debris. Sufficient amounts of additional cobalt are added to ensure the formation of the desired Co(x)W(y)B(z) phase in the final PcBN-based compact. The resulting grinding slurry is then dried by vacuum drying, air drying, freeze drying or spray drying. The resulting dried PcBN material supported on a cemented carbide substrate is further processed by subjecting the PcBN material to a high pressure and high temperature (HPHT) operation by applying the HPHT reaction parameters described in paragraph

[0079] . The resulting sintered PcBN compact is ground to size, cut into suitable shapes, such as triangles of 80° to 120°, and brazed on a carbide tool body to ultimately form a cutting tool.

[0092] Figure 3 and Figure 4 The XRD spectra of Example 1 and Example 2 confirm that the exemplary compact material contains cBN, TiN or ssTiCN ceramic binder phase. The Co(x)W(y)B(z) phase is identified as crystalline CoW2B2. Figure 3 and Figure 4 As shown in FIG. , the cBN phase is identified as a peak occurring at about 7000 intensity counts on the y-axis and about 43° on the x-axis ( Figure 3 00-035-1365 and Figure 4 00-025-1033 in the Figure 3 In FIG. 1 , the TiN phase is represented by peaks occurring at intensity counts of about 1000, 2500, 4500, and 6000 on the y-axis and at about 36°, 42°, 62°, 73°, and 77° on the x-axis ( Figure 3 00-038-1420 in the Figure 4 In the ss TiC 0.7 N0.3 Phases are represented by peaks identified at intensity counts of approximately 1000, 2000, 3000, 6000, and 6800 on the y-axis and approximately 36°, 42°, 62°, 73°, and 77° on the x-axis ( Figure 4 00-042-1489 in the Figure 3 and Figure 4 The CoW2B2 phase with multiple peaks was observed in Figure 3 04-004-0327 and Figure 4 Finally, the phases further identified in the XRD spectrum analysis include at least titanium boride (TiB2, Figure 3 00-008-0121 and Figure 4 00-008-0121), aluminum nitride (AlN, Figure 3 04-006-2061 and Figure 4 00-025-1133) and alumina (Al2O3, Figure 3 00-005-0712 and Figure 4 00-010-0173 in the .

[0093] Scanning electron microscope (SEM) images of the sintered PcBN-based compacts disclosed herein were also prepared to identify the composition of the compacts. Figure 5A and Figure 5B Scanning electron microscope (SEM) images of the microstructure of an exemplary PcBN-based sintered compact containing a titanium nitride (TiN) ceramic binder are shown at 2000x and 10000x magnification, respectively. Fig. 6A and Figure 6B 2 and 3 are scanning electron microscope (SEM) images of the microstructure of an exemplary PcBN-based sintered compact containing ss titanium carbonitride (TiCN) ceramic binder, also depicted at 2000x and 10000x magnifications, respectively. In the SEM images, the cBN grains are identified as Figure 5A and Figure 5B 500 and Fig. 6A and Figure 6B The dark area indicated by reference numeral 600 in the figure. The relatively light metal aluminum was identified as Figure 5A and Figure 5B 502 and Fig. 6A and Figure 6B The relatively dark grey region reflected by reference numeral 602 in FIG. The titanium-containing region is identified as Figure 5A and Figure 5B is reflected by reference numeral 504 and Fig. 6A and Figure 6BFinally, Co and W are both shown as bright white areas, Figure 5A and Figure 5B 506A and 506 respectively and Fig. 6A and Figure 6B 606A and 606, respectively.

[0094] Example 2

[0095] Cutting of surface-hardened 8620 steel using sintered polycrystalline cubic boron nitride (PCBN) based block material

[0096] A workpiece composed of case-hardened 8620 steel was cut using a PcBN-based billet material produced as previously described in paragraph

[0087] , (i) a conventional grade (*) in Table 1, comprising at least about 65% by volume cBN, based on the total volume of the PcBN composition, about 22% by volume to about 23% by volume TiN, based on the total volume of the PcBN composition, 5% by weight Al, 2.6% by weight W, and 0.15% by weight Co, based on the total weight of the PcBN composition, as determined by energy dispersive spectroscopy (EDS) analysis (Formula A indicated by an asterisk (*) in Table 1, with an XRD spectrum as shown in Table 1). Fig. 7A %, based on the total volume of the PcBN composition, about 21 vol% to 22 vol% TiN based on the total volume of the PcBN composition, 5 wt% Al, 6.4 wt% W, and 1.4 wt% Co based on the total weight of the PcBN composition as determined by EDS analysis (Formula B in Table 1, XRD spectrum as shown in Figure 7B ).

[0097] (i) The conventional grade indicated by an asterisk (*) in Table 1 and (ii) the inventive grade both showed cBN grain sizes ranging from about 2 microns to about 4 microns. The feed rate of the case hardened 8620 steel was 0.2 mm / rev, the depth of cut of the case hardened 8620 steel was 0.15 mm, and the cutting speed of the case hardened 8620 steel was 200 m / min. The results obtained are as follows. In mild interruptions, the conventional grade failed due to an average of 0.39 linear kilometers of cutting fracture. On the other hand, the inventive grade was superior, failing due to an average of 0.44 linear kilometers of cutting fracture. In severe interruptions, the conventional grade failed due to an average of 0.34 linear kilometers of cutting fracture. In comparison, the inventive grade performed better again, failing due to an average of 0.41 linear kilometers of fracture.

[0098] Additional formulations were tested, as shown in Table 1, such as conventional grade C (Formulation C), which is indicated by an asterisk (*), having a TiN binder, and an XRD spectrum as shown in Table 1. Figure 7C As shown in FIG. 1 , conventional grade E (formulation E) is also shown with an asterisk (*), which has a TiCN binder and an XRD spectrum as shown in FIG. Fig. 7E As shown in, each is compared with the invention grade D (formulation D) and F (formulation F), and the XRD spectrum is as follows Fig.7D and Figure 7F as shown in .

[0099] As shown in Table 1, the general trend is that the inventive materials exhibit longer tool life in the severe interruption test than their corresponding conventional compositions.

[0100] In summary, the data obtained show that the inventive grade is significantly superior to the conventional grade.

[0101]

[0102] While the present disclosure has been described in conjunction with embodiments thereof, those skilled in the art will appreciate that additions, deletions, modifications and substitutions not specifically described may be made without departing from the spirit and scope of the present disclosure as defined in the appended claims.

[0103] With respect to the use of substantially any plural and / or singular terms herein, those skilled in the art may convert from the plural to the singular and / or from the singular to the plural as appropriate, depending on the context and / or application. For clarity, various singular / plural permutations are not explicitly set forth herein.

[0104] The subject matter described herein sometimes shows the different parts that are contained in different other parts or are connected with different other parts.It should be understood that the structure described in this way is only exemplary, and in fact many other structures that realize the same function can be implemented.In a conceptual sense, any arrangement of the parts realizing the same function is effectively "associated" so that the desired function is realized.Therefore, any two parts that are combined to realize a specific function herein can be regarded as "associated" with each other so that the desired function is realized, regardless of the structure or the intermediate parts.Similarly, any two parts that are so associated can also be regarded as "operably connected" or "operably combined" with each other to realize the desired function, and any two parts that can be so associated can also be regarded as "operably combined" with each other to realize the desired function.The specific example that can be operably combined includes but is not limited to physically matchable and / or physically interactive parts, and / or wirelessly interactive and / or wirelessly interactive parts, and / or logically interactive and / or logically interactive parts.

[0105] In some cases, one or more components may be referred to herein as being "configured to," "configured by," "configurable to," "operable / operable to," "adapted / adaptable," "capable of," "conformable / conformable to," etc. Those skilled in the art will recognize that such terms (e.g., "configured to") may generally encompass active state components and / or inactive state components and / or standby state components unless the context requires otherwise.

[0106] Although particular aspects of the subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based on the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects, and therefore, the appended claims will cover within their scope all such changes and modifications that are within the true spirit and scope of the subject matter described herein. Those skilled in the art will understand that, in general, the terms used herein, especially in the appended claims (e.g., the bodies of the appended claims), are generally intended to be "open" terms (e.g., the term "including" should be interpreted as "including but not limited to", the term "having" should be interpreted as "having at least", the term "comprising" should be interpreted as "including but not limited to", etc.).

[0107] Those skilled in the art will further understand that if a specific number of claim statements are intended to be introduced, such intent will be explicitly stated in the claim, and in the absence of such a statement, no such intent exists. For example, to aid understanding, the appended claims may contain the use of the introductory phrases "at least one" and "one or more" to introduce claim statements. However, the use of such phrases should not be interpreted as implying that a claim statement introduced by the indefinite article "a" or "an" will limit any particular claim containing such introduced claim statement to a claim containing only one such feature, even when the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should generally be interpreted as meaning "at least one" or "one or more"); the same is true for the use of definite articles used to introduce claim statements.

[0108] In addition, even if a specific number of an introduced claim statement is explicitly recited, those skilled in the art will recognize that such a statement should generally be interpreted to mean at least the stated number (e.g., a bare statement of "two statements" without other modifiers generally means at least two statements, or more than two statements).

[0109] Furthermore, in those cases where a convention similar to “at least one of A, B, and C, etc.” is used, generally such construction is intended to mean that one skilled in the art will understand the convention (e.g., “a system having at least one of A, B, and C” will include but is not limited to systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those cases where a convention similar to “at least one of A, B, or C, etc.” is used, generally such construction is intended to mean that one skilled in the art will understand the convention (e.g., “a system having at least one of A, B, or C” will include but is not limited to systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). One skilled in the art will further understand that generally disjunctive words and / or phrases (whether in the specification, claims, or drawings) that present two or more alternative terms should be understood to contemplate the possibility of including one, either, or both terms, unless the context dictates otherwise. For example, the phrase "A or B" will generally be understood to include the possibilities of "A" or "B" or "A and B."

[0110] With respect to the appended claims, those skilled in the art will appreciate that the operations stated therein may generally be performed in any order. Moreover, although various operational flows are presented in order, it should be understood that the various operations may be performed in an order different from the order shown, or may be performed simultaneously. Unless the context otherwise dictates, examples of such alternative orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplementary, simultaneous, reverse, or other variant orderings. In addition, terms such as "responsive to," "about," or other past tense adjectives are generally not intended to exclude such variants, unless the context otherwise dictates.

[0111] Those skilled in the art will appreciate that the foregoing specific exemplary processes and / or apparatus and / or techniques represent more general processes and / or apparatus and / or techniques taught elsewhere herein, such as in the claims filed herein and / or elsewhere in this application.

[0112] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

[0113] The exemplary embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here.

[0114] Where a range of values ​​is provided, it is understood that each intervening value (to the tenth of the unit of the lower limit unless the context clearly dictates otherwise) between the upper and lower limits of that range and any other stated value or intervening value in that stated range is encompassed within the disclosed range. The upper and lower limits of these smaller ranges, which may independently be included in smaller ranges, are also encompassed within the disclosed content, subject to any specifically excluded limits in the stated range. Where the stated range includes one or both of the limits, ranges excluding one or both of those included limits are also encompassed within the disclosed content.

[0115] Those skilled in the art will recognize that for conceptual clarity, the components (e.g., operations), devices, objects, and discussions accompanying them described herein are used as examples, and various configuration modifications are contemplated. Therefore, as used herein, the specific examples set forth and the accompanying discussions are intended to represent their more general categories. In general, the use of any specific example is intended to represent its category, and the exclusion of specific components (e.g., operations), devices, and objects should not be considered limiting.

[0116] Additionally, for example, any sequence and / or chronological order of the systems and methods described herein is exemplary and should not be construed as being limiting in nature. Thus, it should be understood that process steps may be shown and described as being in sequence or chronological order, but they are not necessarily limited to being performed in any particular order or sequence. For example, the steps in such a process or method may generally be performed in a variety of different sequences and orders while still falling within the scope of the present disclosure.

[0117] Finally, the applications, publications and / or patents discussed herein are provided solely for their disclosure prior to the filing date of the disclosure. Nothing herein should be construed as an admission that the disclosed disclosure is not entitled to antedate such publication by virtue of prior publication.

Claims

1. A polycrystalline cubic boron nitride (PcBN) composition comprising: From about 60 volume % to about 80 volume % of a cBN hard phase based on the total volume of the PcBN composition; and From about 20 volume % to about 40 volume % of a ceramic binder phase based on the total volume of the PcBN composition, wherein the ceramic binder phase comprises AlN phase, Al2O3 phase, and At least one ductile Co(x)W(y)B(z) phase.

2. The PcBN composition of claim 1, wherein the ceramic binder phase comprises substoichiometric (ss) titanium nitride (TiN), titanium carbonitride (TiCN), or a combination thereof.

3. The PcBN composition of claim 1, wherein the ceramic binder phase comprises substoichiometric or stoichiometric TiNO, TiCNO, or a combination thereof.

4. The PcBN composition of claim 1, wherein the grain size of the cBN grains is in the range of from about 3 microns to about 6 microns.

5. The PcBN composition of claim 4, wherein the cBN grains have a grain size ranging from about 2 microns to about 4 microns.

6. The PcBN composition of claim 1, wherein the grain size of the Co grains is in the range from about 0.1 microns to about 1 micron.

7. The PcBN composition of claim 1, wherein the grain size of the tungsten carbide (WC) grains is in a range from about 0.1 microns to about 1 micron.

8. The PcBN composition of claim 1, wherein (x) is 1, (y) is 2, and (z) is 2, and the at least one Co(x)W(y)B(z) tough phase comprises CoW2B2.

9. The PcBN composition of claim 1, wherein (x) is 1, (y) is 1, and (z) is 1, and the at least one Co(x)W(y)B(z) tough phase comprises CoWB.

10. The PcBN composition of claim 1, wherein the amount of aluminum is in a range from about 3 wt % to about 6 wt %, the amount of cobalt is in a range from about 0.9 wt % to about 2.5 wt %, and the amount of tungsten is in a range from about 5 wt % to about 8 wt %, based on the total weight of the PcBN composition.

11. A method for manufacturing a sintered polycrystalline cubic boron nitride (PcBN) compact, comprising: Grinding a powder mixture with a grinding body comprising at least tungsten carbide (WC) to form a powder blend and produce grinding chips, the powder mixture comprising powders forming the following hard components: (i) from about 60 volume % to about 80 volume % of a cBN hard phase based on the total volume of the powder mixture and (ii) from about 20 volume % to about 40 volume % of a ceramic binder phase based on the total volume of the powder mixture; drying the powder blend; and The components of the powder blend are reacted under high pressure and high temperature (HPHT) conditions to form an AlN phase, an Al2O3 phase, and at least one tough Co(x)W(y)B(z) phase in the ceramic binder phase.

12. The method of manufacturing a sintered PcBN compact according to claim 11, wherein the ceramic binder phase comprises substoichiometric (ss) titanium nitride (TiN), titanium carbonitride (TiCN), or a combination thereof.

13. The method for manufacturing a sintered PcBN compact according to claim 11, wherein the ceramic binder phase comprises substoichiometric or stoichiometric TiNO, TiCNO or a combination thereof.

14. The method of making a sintered PcBN compact according to claim 11, wherein the grain size of the cBN grains is in the range from about 3 microns to about 6 microns.

15. The method of making a sintered PcBN compact according to claim 14, wherein the grain size of the cBN grains is in the range from about 2 microns to about 4 microns.

16. The method of making a sintered PcBN compact according to claim 11, wherein the grain size of the Co grains is in the range from about 0.1 microns to about 1 micron.

17. The method of making a sintered PcBN compact according to claim 11, wherein the grain size of tungsten carbide (WC) grains in the grinding chips is in the range of from about 0.1 microns to about 1 micron.

18. The method of making a sintered PcBN compact according to claim 11, wherein drying the powder blend comprises vacuum drying, air drying, freeze drying or spray drying.

19. The method for manufacturing a sintered PcBN compact according to claim 11, wherein the grinding is performed using one or more solvents as grinding slurry of the powder blend, the solvent comprising ethanol, methanol, isopropanol, butanol, cyclohexanol, acetone, hexane, heptane, toluene, water or any combination thereof.

20. The method of making a sintered PcBN compact according to claim 11, wherein the HPHT conditions include a pressure ranging from about 4 gigapascals (GPa) to about 8 GPa and a temperature ranging from about 1100°C to about 1800°C.

21. The method of making a sintered PcBN compact according to claim 11, wherein (x) is 1, (y) is 2, and (z) is 2, and the at least one Co(x)W(y)B(z) tough phase comprises CoW2B2.

22. The method of making a sintered PcBN compact according to claim 11, wherein (x) is 1, (y) is 1, and (z) is 1, and the at least one Co(x)W(y)B(z) tough phase comprises CoWB.

23. The method for manufacturing a sintered PcBN compact according to claim 11, wherein the amount of aluminum is in a range from about 3 wt% to about 6 wt%, the amount of cobalt is in a range from about 0.9 wt% to about 2.5 wt%, and the amount of tungsten is in a range from about 5 wt% to about 8 wt%, based on the total weight of the PcBN compact.

24. The method of making a sintered PcBN compact according to claim 11, further comprising loading the powder blend into a refractory metal cup after drying the powder blend.

25. A cutting tool comprising the PcBN composition according to claim 1.

26. A compact comprising the PcBN composition according to claim 1.

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