# US 2009/0260482 A1 · Materials for enhancing the durability of earth-boring bits, and methods of forming such materials > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260482 A1 - Document ID: US20090260482A1 - Status: Published application - Kind: A1 - Application number: 12/391,690 - Filed: 2009-02-24 - Published: 2009-10-22 - Earliest claimed: 2005-10-11 - Assignees: Baker Hughes Incorporated - Inventors: David A. Curry; James L. Overstreet; Jimmy W. Eason - Web page: https://patentgrep.com/patent/US20090260482A1 ## CPC - C22C 29/08: based on tungsten carbide - E21B 10/46: characterised by wear resisting parts, e.g. diamond inserts - B22F 2005/001: {Cutting tools, earth boring or grinding tool other than table ware} - B22F 2998/00: Supplementary information concerning processes or compositions relating to powder metallurgy - C22C: ALLOYS (treatment of alloys C21D, C22F) - 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 ## Abstract An earth-boring drill bit having a bit body with a cutting component formed from a tungsten carbide composite material is disclosed. The composite material includes a binder and tungsten carbide crystals comprising sintered pellets. The composite material may be used as a hardfacing on the body and/or cutting elements, or be used to form portions or all of the body and cutting elements. The pellets may be formed with a single mode or multi-modal size distribution of the crystals. ## Claims ### Claim 1 A composite material, comprising: crystals of tungsten carbide and a binder, the crystals having a generally spheroidal shape, a mean grain size range of about 0.5 to 8 microns, and a distribution of which is characterized by a Gaussian distribution having a standard deviation on the order of about 0.25 to 0.50 microns. ### Claim 2 (depends on 1) A composite material according to claim 1, wherein the binder is one of an alloy binder, a transition element binder, and a cobalt alloy comprising about 6% to 8% cobalt. ### Claim 3 (depends on 1) A composite material according to claim 1, wherein the composite material comprises bi-modal, sintered spheroidal pellets that incorporate an aggregate of two different sizes of the crystals, and the two different sizes of the crystals have a size ratio of about 7:1, provide the composite material with a tungsten carbide content of about 88%, a larger size of the crystals has a mean size of ≦8 microns, and a smaller size of the crystals has a mean size of about 1 micron. ### Claim 4 (depends on 1) A composite material according to claim 1, wherein the composite material comprises tri-modal, sintered spheroidal pellets that incorporate an aggregate of three different sizes of the crystals, the three different sizes of the crystals have a size ratio of about 35:7:1, provide the composite material with a carbide content of greater than 90%, a largest size of the crystals has a mean size of <8 microns, an intermediate size of the crystals has a mean size of about 1 micron, and a smallest size of the crystals has a mean size of about 0.03 microns. ### Claim 5 A hardfacing material for drill bits, the hardfacing material comprising: hard phase components held together by a metal matrix, the hard phase components comprising crystals of tungsten carbide and a binder, the crystals having a generally spheroidal shape, a mean grain size range of about 0.5 to 8 microns, and a distribution of which is characterized by a Gaussian distribution having a standard deviation on the order of about 0.25 to 0.50 microns. ### Claim 6 (depends on 5) A hardfacing material according to claim 5, wherein the hard phase components comprise at least one of cast tungsten carbide and cemented tungsten carbide pellets. ### Claim 7 (depends on 5) A hardfacing material according to claim 5, wherein the metal matrix comprises one of iron and nickel. ### Claim 8 (depends on 5) A hardfacing material according to claim 5, wherein the binder is one of an alloy binder, a transition element binder, and a cobalt alloy comprising about 6% to 8% cobalt. ### Claim 9 (depends on 5) A composite material according to claim 5, wherein the composite material comprises bi-modal, sintered spheroidal pellets that incorporate an aggregate of two different sizes of the crystals, and the two different sizes of the crystals have a size ratio of about 7:1, provide the composite material with a tungsten carbide content of about 88%, a larger size of the crystals has a mean size of ≦8 microns, and a smaller size of the crystals has a mean size of about 1 micron. ### Claim 10 (depends on 5) A composite material according to claim 5, wherein the composite material comprises tri-modal, sintered spheroidal pellets that incorporate an aggregate of three different sizes of the crystals, the three different sizes of the crystals have a size ratio of about 35:7:1, provide the composite material with a carbide content of greater than 90%, a largest size of the crystals has a mean size of <8 microns, an intermediate size of the crystals has a mean size of about 1 micron, and a smallest size of the crystals has a mean size of about 0.03 microns. ### Claim 11 A method of forming a composite material, comprising: providing crystals of tungsten carbide having a mean grain size range of about 0.5 to 8 microns, a distribution of which is characterized by a Gaussian distribution; forming a bulk composite of the crystals and a binder; sintering the bulk composite; crushing the bulk composite to form crushed particles having non-uniform, irregular shapes; and sorting the crushed particles by size for use in selected applications. ### Claim 12 (depends on 11) A method according to claim 11, wherein forming a bulk composite of the crystals and a binder comprises forming a billet of the crystals and binder. ### Claim 13 (depends on 11) A method according to claim 11, wherein forming a bulk composite of the crystals and a binder comprises selecting the binder from one of an alloy binder, a transition element binder, and a cobalt alloy comprising about 6% to 8% cobalt. ### Claim 14 (depends on 11) A method according to claim 11, wherein providing crystals of tungsten carbide comprises formulating bi-modal, sintered spheroidal pellets that incorporate an aggregate of two different sizes of the crystals, and the two different sizes of the crystals have a size ratio of about 7:1, provide the composite material with a tungsten carbide content of about 88%, a larger size of the crystals has a mean size of <8 microns, and a smaller size of the crystals has a mean size of about 1 micron. ### Claim 15 (depends on 11) A method according to claim 11, wherein providing crystals of tungsten carbide comprises formulating tri-modal, sintered spheroidal pellets that incorporate an aggregate of three different sizes of the crystals, the three different sizes of the crystals have a size ratio of about 35:7:1, provide the composite material with a carbide content of greater than 90%, a largest size of the crystals has mean size of <8 microns, an intermediate size of the crystals has a mean size of about 1 micron, and a smallest size of the crystals has a mean size of about 0.03 microns. ### Claim 16 A method of forming a composite material, comprising: providing crystals of tungsten carbide having a mean grain size range of about 0.5 to 8 microns, a distribution of which is characterized by a Gaussian distribution; and forming pellets of the crystals and a binder. ### Claim 17 (depends on 16) A method according to claim 16, wherein forming pellets of the crystals and a binder comprises selecting the binder from one of an alloy binder, a transition element binder, and a cobalt alloy comprising about 6% to 8% cobalt. ### Claim 18 (depends on 16) A method according to claim 16, wherein providing crystals of tungsten carbide comprises formulating bi-modal, sintered spheroidal pellets that incorporate an aggregate of two different sizes of the crystals, and the two different sizes of the crystals have a size ratio of about 7:1, provide the composite material with a tungsten carbide content of about 88%, a larger size of the crystals has a mean size of ≦8 microns, and a smaller size of the crystals has a mean size of about 1 micron. ### Claim 19 (depends on 16) A method according to claim 16, wherein providing crystals of tungsten carbide comprises formulating tri-modal, sintered spheroidal pellets that incorporate an aggregate of three different sizes of the crystals, the three different sizes of the crystals have a size ratio of about 35:7:1, provide the composite material with a carbide content of greater than 90%, a largest size of the crystals has a mean size of <8 microns, an intermediate size of the crystals has a mean size of about 1 micron, and a smallest size of the crystals has a mean size of about 0.03 microns.