# US 2008/0302579 A1 · Polycrystalline diamond cutting elements having improved thermal resistance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0302579 A1 - Document ID: US20080302579A1 - Status: Published application - Kind: A1 - Application number: 11/758,537 - Filed: 2007-06-05 - Published: 2008-12-11 - Earliest claimed: 2007-06-05 - Assignees: Smith International, Inc. - Inventors: Madapusi K. KESHAVAN; Peter Thomas CARIVEAU - Web page: https://patentgrep.com/patent/US20080302579A1 ## CPC - E21B 10/5735: {Interface between the substrate and the cutting element} - B22F 7/08: with one or more parts not made from powder {(B22F7/062 takes precedence)} - C04B 35/52: based on carbon, e.g. graphite - C22C 26/00: Alloys containing diamond {or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes} - E21B 10/54: the bit being of the rotary drag type, e.g. fork-type bits - E21B 10/567: with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts - B22F 2005/001: {Cutting tools, earth boring or grinding tool other than table ware} - B22F 2005/002: {Tools other than cutting tools} - C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina - C04B 2235/3224: Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide - C04B 2235/3232: Titanium oxides or titanates, e.g. rutile or anatase - C04B 2235/3234: Titanates, not containing zirconia - C04B 2235/3244: Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof - C04B 2235/3418: Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint - C04B 2235/3427: Silicates other than clay, e.g. water glass - C04B 2235/3436: Alkaline earth metal silicates, e.g. barium silicate - C04B 2235/3445: Magnesium silicates, e.g. forsterite - C04B 2235/3454: Calcium silicates, e.g. wollastonite - C04B 2235/3826: Silicon carbides - C04B 2235/3839: Refractory metal carbides - C04B 2235/3843: Titanium carbides - C04B 2235/3847: Tungsten carbides - C04B 2235/3865: Aluminium nitrides - C04B 2235/3869: Aluminium oxynitrides, e.g. AlON, sialon - C04B 2235/3873: Silicon nitrides, e.g. silicon carbonitride, silicon oxynitride - C04B 2235/3886: Refractory metal nitrides, e.g. vanadium nitride, tungsten nitride - C04B 2235/404: Refractory metals - C04B 2235/427: Diamond - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - C22C: ALLOYS (treatment of alloys C21D, C22F) ## Abstract Polycrystalline diamond constructions of this invention have a polycrystalline diamond body and a substrate attached thereto, wherein the diamond body has a material microstructure comprising a plurality of bonded-together diamond crystals forming a polycrystalline matrix phase, and second phase formed from different types of materials or sintering aids designed to reduce or eliminate the amount of free Group VIII elements therein. The use of such materials and the reduction and/or elimination of free Group VIII elements, in addition to graphitization, facilitates the sintering the construction at high pressure/high temperature conditions, e.g., greater than about 65 Kbar, to produce a construction having a high degree of thermal stability and/or thermal resistance when compared to conventional PCD materials. Polycrystalline diamond constructions of this invention are preferably configured as cutting elements that are disposed on drill bits used for drilling subterranean earthen formations. ## Claims ### Claim 1 An earth boring drill bit comprising: a body having a number of cutting elements attached thereto, wherein one or more of the cutting elements includes a polycrystalline diamond construction having a material microstructure comprising: a plurality of bonded-together diamond crystals forming a polycrystalline matrix phase, and an intermetallic compound interposed within a boundary phase between the bonded-together diamond crystals, wherein the intermetallic compound comprises a combination or reaction product of one or more materials selected from Group VIII of the Periodic Table, with Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof; and a substrate attached to the polycrystalline diamond construction, and wherein the substrate is formed from a material selected from the group consisting of ceramics, metals, cermets, and combinations thereof; wherein the polycrystalline diamond construction is prepared by the process of: graphitizing part or all of a precursor diamond powder used to form the polycrystalline diamond construction, sintering the diamond powder in the presence of precursor materials used to form the intermetallic compound under high pressure conditions of greater than about 55 Kbar, and under high temperature conditions to form the polycrystalline diamond construction; and attaching the polycrystalline diamond construction to the substrate. ### Claim 2 (depends on 1) The drill bit as recited in claim 1 wherein the body includes one or more blades projecting outwardly therefrom, and the number of cutting elements are attached to the one or more blades, and wherein the polycrystalline diamond construction forms at least part of a working surface of the cutting element. ### Claim 3 (depends on 1) The drill bit as recited in claim 1 further comprising a number of legs extending away from the body, and a number of cones rotatably attached to the legs, wherein the number of cutting elements are attached to one or more of the cones, and wherein the polycrystalline diamond construction forms at least part of a working surface of the cutting element. ### Claim 4 (depends on 1) The drill bit as recited in claim 1 wherein the polycrystalline diamond construction further comprises Pd. ### Claim 5 (depends on 4) The drill bit as recited in claim 4 wherein the Pd is disposed on a surface of diamond grains in the diamond powder before the step of sintering. ### Claim 6 (depends on 5) The drill bit as recited in claim 5 wherein the precursor material used to form the intermetallic compound is disposed on a surface of the Pd layer disposed on the diamond grains. ### Claim 7 (depends on 1) The drill bit as recited in claim 1 wherein the substrate comprises a Group VIII element from the Periodic table, and an intermediate layer is interposed between the polycrystalline diamond construction and the substrate, and wherein the intermediate layer is formed from a material that is substantially free of a Group VIII element of the Periodic table. ### Claim 8 (depends on 1) The drill bit as recited in claim 1 wherein the substrate is formed from a cermet material that is substantially free of a Group VIII element of the Periodic table. ### Claim 9 (depends on 1) The drill bit as recited in claim 1 wherein the intermetallic compound comprises a carbide of the materials selected from the group consisting of Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof. ### Claim 10 (depends on 1) The drill bit as recited in claim 1 wherein the step of sintering the polycrystalline diamond construction takes place at a pressure of greater than about 65 Kbar. ### Claim 11 (depends on 1) The drill bit as recited in claim 1 wherein the step of sintering the polycrystalline diamond construction takes place at a pressure of greater than about 70 Kbar. ### Claim 12 (depends on 1) The drill bit as recited in claim 1 wherein the step of sintering the polycrystalline diamond construction takes place at a temperature of from about 1,400 to 1,600 C. ### Claim 13 (depends on 1) The drill bit as recited in claim 1 wherein during the step of graphitizing, less than about 10 percent by volume of diamond grains in the diamond powder are graphitized. ### Claim 14 (depends on 1) The drill bit as recited in claim 1 wherein during the step of graphitization, less than about 5 atomic layers of graphite are formed on diamond grains in the diamond powder. ### Claim 15 (depends on 1) The drill bit as recited in claim 1 wherein one or more of the materials selected from the group consisting of Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof is present within the diamond grains before sintering. ### Claim 16 (depends on 1) The drill bit as recited in claim 1 wherein one or more of the materials selected from the group consisting of Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof is added to the diamond grains to form a diamond mixture before sintering. ### Claim 17 (depends on 1) The drill bit as recited in claim 1 wherein the materials used to make the intermetallic compound comprises in the range of 0.01 to 10 percent by weight Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof. ### Claim 18 (depends on 1) The drill bit as recited in claim 1 wherein before the step of sintering, the diamond powder is disposed within a container that is sealed off from the atmosphere. ### Claim 19 (depends on 1) The drill bit as recited in claim 1 wherein the polycrystalline diamond construction has a diamond volume content of greater than about 94 percent. ### Claim 20 (depends on 1) The drill bit as recited in claim 1 wherein the polycrystalline diamond construction is substantially free of a material consisting exclusively of a Group VIII element of the Periodic table. ### Claim 21 A polycrystalline diamond construction comprising: a polycrystalline diamond body having a material microstructure comprising a plurality of bonded-together diamond crystals forming a polycrystalline matrix phase, and an intermetallic compound interposed within a boundary phase between the bonded-together diamond crystals, wherein the intermetallic compound comprises a combination or reaction product of one or more materials selected from Group VIII of the Periodic Table, with Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof, wherein the polycrystalline diamond body is substantially free of a material consisting exclusively of a Group VIII element of the Periodic table; and a substrate attached to the polycrystalline diamond construction, wherein the substrate is formed from a material selected from the group consisting of ceramics, metals, cermets, and combinations thereof that are substantially free of a Group VIII element of the Periodic table; wherein the polycrystalline diamond construction is prepared by the process of: placing the diamond powder within a container that is sealed off from the atmosphere; sintering the diamond powder in the presence of the materials used to form the intermetallic compound under high pressure conditions of greater than about 55 Kbar, and under high temperature conditions to form the polycrystalline diamond construction, wherein some or all of the materials used to form the intermetallic compound is present in the diamond grains forming the diamond powder; and attaching the polycrystalline diamond construction to the substrate. ### Claim 22 (depends on 21) The polycrystalline diamond construction as recited in claim 21 wherein the intermetallic compound is a carbide. ### Claim 23 (depends on 22) The polycrystalline diamond construction as recited in claim 22 wherein the materials used to make the intermetallic compound comprises in the range of 0.01 to 10 percent by weight Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof. ### Claim 24 (depends on 21) The polycrystalline diamond construction as recited in claim 21 wherein the process of preparing further comprises graphitizing part or all of a precursor diamond powder used to form the polycrystalline diamond body. ### Claim 25 A polycrystalline diamond construction comprising: a polycrystalline diamond body having a material microstructure comprising a plurality of bonded-together diamond crystals forming a polycrystalline matrix phase, and an intermetallic compound interposed within a boundary phase between the bonded-together diamond crystals, wherein the intermetallic compound comprises a combination or reaction product of one or more materials selected from Group VIII of the Periodic Table, with Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof, wherein the polycrystalline diamond body is substantially free of a material consisting exclusively of a Group VIII element of the Periodic table, and has a diamond volume content of greater than about 96 percent; and a substrate attached to the polycrystalline diamond construction, wherein the substrate is formed from a material selected from the group consisting of ceramics, metals, cermets, and combinations thereof; wherein the polycrystalline diamond construction comprises a diamond content of about 96 percent by volume or more and is prepared by the process of: graphitizing part or all of a precursor diamond powder used to form the polycrystalline diamond body; placing the diamond powder within a container that is sealed off from the atmosphere; sintering the diamond powder in the presence of the materials used to form the intermetallic compound under high pressure conditions of greater than about 55 Kbar, and under high temperature conditions to form the polycrystalline diamond construction, wherein the materials used to form the intermetallic compound are combined with the diamond powder to form a mixture prior to sintering; and attaching the polycrystalline diamond construction to the substrate. ### Claim 26 (depends on 25) The polycrystalline diamond construction as recited in claim 25 wherein the intermetallic compound is a carbide. ### Claim 27 (depends on 26) The polycrystalline diamond construction as recited in claim 26 wherein the materials used to make the intermetallic compound comprises in the range of 0.01 to 10 percent by weight Cr, Mn, Ti, Zr, Hf, V, Nb, Mo, W, Ta, and alloys thereof. ### Claim 28 An earth boring drill bit comprising: a body and a number of cutting elements attached thereto, one or more of the cutting elements comprising a polycrystalline diamond construction that is formed from a plurality of bonded-together diamond crystals, wherein the polycrystalline diamond construction comprises: a polycrystalline diamond body having a diamond volume content of greater than about 94 percent; and a substrate attached to the polycrystalline diamond body, wherein the substrate is formed from a material selected from the group consisting of ceramics, metals, cermets, and combinations thereof; wherein the polycrystalline diamond construction is prepared by the process of: graphitizing part or all of a precursor diamond powder used to form the polycrystalline diamond construction; combining the graphitized diamond powder with a sintering agent comprising Pd and one or more further material selected from the group consisting of Fe, Co, Ni, to form a diamond powder mixture, wherein the Pd is disposed on a surface of diamond grains in the diamond powder and the one or more further material is disposed on the Pd, and wherein the Pd and one or more further materials are distributed homogeneously within the diamond powder mixture; sintering the diamond powder mixture under a high pressure condition of greater than about 55 Kbar and a high temperature condition; and attaching the diamond body to the substrate to form the polycrystalline diamond construction. ### Claim 29 (depends on 28) The drill bit as recited in claim 28 wherein the body includes one or more blades projecting outwardly therefrom, and the number of cutting elements are attached to the one or more blades, and wherein the polycrystalline diamond construction forms at least part of a working surface of the cutting element. ### Claim 30 (depends on 28) The drill bit as recited in claim 28 further comprising a number of legs extending away from the body, and a number of cones rotatably attached to the legs, wherein the number of cutting elements are attached to one or more of the cones, and wherein the polycrystalline diamond construction forms at least part of a working surface of the cutting element. ### Claim 31 (depends on 28) The drill bit as recited in claim 28 wherein the Pd comprises from 0.01 to 40 percent by weight of the total sintering agent. ### Claim 32 (depends on 28) The drill bit as recited in claim 28 wherein the sintering is conducted at a pressure of greater than about 70 Kbar. ### Claim 33 (depends on 28) The drill bit as recited in claim 28 wherein the sintering is conducted at a temperature of greater than about 1600° C. ### Claim 34 (depends on 28) The drill bit as recited in claim 28 wherein the sintering agent additionally comprises one or more material selected from the group consisting of Sn, P, B, and mixtures thereof. ### Claim 35 (depends on 28) The drill bit as recited in claim 28 wherein the sintering agent additional comprises a tungsten material. ### Claim 36 (depends on 28) The drill bit as recited in claim 28 wherein the substrate is a cermet material comprising a Group VIII element of the Periodic table, and wherein the cutting element further comprises an intermediate layer interposed between the substrate and the polycrystalline diamond body that is formed from a material that is substantially free of Group VIII elements of the Periodic table. ### Claim 37 (depends on 28) The drill bit as recited in claim 28 wherein the substrate is a cermet material that is substantially free from Group VIII elements of the Periodic table. ### Claim 38 (depends on 28) The drill bit as recited in claim 28 wherein during the step of graphitizing, less than about 10 percent by volume of diamond grains in the diamond powder are graphitized. ### Claim 39 (depends on 28) The drill bit as recited in claim 28 wherein during the step of graphitization, less than about 5 atomic layers of graphite are formed on diamond grains in the diamond powder. ### Claim 40 An earth boring drill bit comprising: a body having a number of cutting attached thereto, one or more of the cutting elements comprising a polycrystalline diamond construction comprising: a polycrystalline diamond body comprising a plurality of bonded-together diamond crystals; and a substrate attached to the polycrystalline diamond body, wherein the substrate is formed from a material selected from the group consisting of ceramics, metals, cermets, and combinations thereof; wherein the polycrystalline diamond construction is prepared by the process of: graphitizing part or all of a precursor diamond powder used to form the polycrystalline diamond body; combining the graphitized diamond powder with a sintering aid comprising a compound having one or more elements selected from the group consisting of Fe, Co, Ni, Mn, Ti, TiO2, Si, Alkali earth metals, Alkaline earth metals, rare earth elements, and O, wherein the compound is selected from the group consisting of silicates, titanates, and oxides, and wherein the diamond powder and the sintering aid is disposed within a container that is sealed off from the atmosphere; sintering the diamond powder and sintering aid under high pressure conditions of greater than about 70 Kbar, and under high temperature conditions to form the polycrystalline diamond body; and attaching the polycrystalline diamond body to the substrate. ### Claim 41 (depends on 40) The drill bit as recited in claim 40 wherein the body includes one or more blades projecting outwardly therefrom, and the number of cutting elements are attached to the one or more blades, and wherein the polycrystalline diamond construction forms at least part of a working surface of the cutting element. ### Claim 42 (depends on 40) The drill bit as recited in claim 40 further comprising a number of legs extending away from the body, and a number of cones rotatably attached to the legs, wherein the number of cutting elements are attached to one or more of the cones, and wherein the polycrystalline diamond construction forms at least part of a working surface of the cutting element. ### Claim 43 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a titanate of a metal selected from the group consisting of Fe, Co, Ni, and Mn. ### Claim 44 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a titanate of one or more materials selected from the group consisting of Ti, alkali metals, alkaline earth metals, and O. ### Claim 45 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a titanate of one or more materials selected from the group consisting of Ti, rare earth elements, and O. ### Claim 46 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a composite oxide or solid solution of an oxide of one or more materials selected from the group consisting of Fe, Co, Ni, Mn, and TiO2. ### Claim 47 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a composite oxide or solid solution of an oxide of one or more materials selected from the group consisting of TiO2, alkali metals, and alkaline earth metals. ### Claim 48 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a composite oxide or solid solution of an oxide of one or more materials selected from the group consisting of SiO2, and alkaline earth metals. ### Claim 49 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a composite oxide or solid solution of an oxide of one or more materials selected from the group consisting of SiO2, and rare earth elements. ### Claim 50 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a composite oxide or solid solution of an oxide of one or more materials selected from the group consisting of SiO2, and TiO2. ### Claim 51 (depends on 40) The drill bit as recited in claim 40 wherein the compound is a silicate of one or more materials selected from the group consisting of alkaline earth elements, and rare earth elements. ### Claim 52 (depends on 40) The drill bit as recited in claim 40 wherein the substrate is a cermet material comprising a Group VIII element of the Periodic table, and wherein the cutting element further comprises an intermediate layer interposed between the substrate and the polycrystalline diamond body that is formed from a material that is substantially free of a Group VIII element of the Periodic table. ### Claim 53 (depends on 40) The drill bit as recited in claim 40 wherein the substrate is carbide material that is substantially free of a Group VIII element of the Periodic table. ### Claim 54 (depends on 40) The drill bit as recited in claim 40 wherein during the step of graphitizing, less than about 10 percent by volume of diamond grains in the diamond powder are graphitized. ### Claim 55 (depends on 40) The drill bit as recited in claim 40 wherein during the step of graphitization, less than about 5 atomic layers of graphite are formed on diamond grains in the diamond powder.