# US 2018/0021924 A1 · Super hard components and powder metallurgy methods of making the same

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- Number: US 2018/0021924 A1
- Document ID: US20180021924A1
- Status: Published application
- Kind: A1
- Application number: 15/540,782
- Filed: 2015-12-30
- Published: 2018-01-25
- Earliest claimed: 2014-12-31
- Assignees: Element Six (UK) Limited
- Applicants: Element Six (UK) Limited
- Inventors: Dong WANG
- Web page: https://patentgrep.com/patent/US20180021924A1

## CPC

- B24D 18/0009: {using moulds or presses}
- C04B 35/528: obtained from carbonaceous particles with or without other non-organic components
- C04B 35/6264: {Mixing media, e.g. organic solvents}
- C04B 35/62655: {Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying}
- C04B 35/63416: {Polyvinylalcohols [PVA]; Polyvinylacetates}
- C04B 35/645: Pressure sintering
- C04B 37/021: {in a direct manner, e.g. direct copper bonding [DCB]}
- C22C 26/00: Alloys containing diamond {or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes}
- B22F 9/026: {Spray drying of solutions or suspensions}
- B22F 2005/001: {Cutting tools, earth boring or grinding tool other than table ware}
- C04B 2235/40: Metallic constituents or additives not added as binding phase
- C04B 2235/427: Diamond
- C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron
- C04B 2235/5445: submicron sized, i.e. from 0,1 to 1 micron
- C04B 2235/5472: Bimodal, multi-modal or multi-fraction
- C04B 2235/96: Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B 2237/363: Carbon
- C04B 2237/401: Cermets
- C22C 2204/00: End product comprising different layers, coatings or parts of cermet
- B24D: TOOLS FOR GRINDING, BUFFING OR SHARPENING (abrading-bodies specially designed for tumbling apparatus, e.g. abrading-balls B24B31/14; honing tools B24B33/08; lapping tools B24B37/11)
- 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)
- 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

A method of forming a super hard polycrystalline construction comprises forming a liquid suspension of graphene and grains of super hard material, dispersing the graphene and super hard grains in the liquid suspension to form a substantially homogeneous suspension which is dried and from which a pre-sinter assembly is formed and then treated to create a sintered body of polycrystalline super hard material comprising a first fraction of super hard grains and a second fraction of diamond grains, the graphene being at least partially converted to diamond during the sintering stage to form the second fraction. The super hard grains in the first fraction are bonded along at least a portion of the peripheral surface to at least a portion of a plurality of diamond grains in the second fraction, and have a greater average grain size than that of the grains in the second fraction which is between 60 nm to 1 micron.

## Claims

### Claim 1

A method of forming a super hard polycrystalline construction, comprising:
forming a liquid suspension of a first mass of graphene and a mass of particles or grains of super hard material;
dispersing the graphene and mass of super hard particles or grains in the liquid suspension to form a substantially homogeneous suspension;
drying the suspension to form an admix of the graphene and super hard grains or particles;
forming a pre-sinter assembly comprising the admix;
treating the pre-sinter assembly in the presence of a catalyst/solvent material for the super hard grains at an ultra-high pressure of around 5 GPa or greater and a temperature to sinter together the grains of super hard material to form a body of polycrystalline super hard material comprising a first fraction of super hard grains and a second fraction of diamond grains, the super hard grains exhibiting inter-granular bonding and defining a plurality of interstitial regions therebetween;
the graphene being at least partially converted to diamond during the sintering stage to form the second fraction; wherein
the super hard grains in the first fraction are bonded along at least a portion of the peripheral surface to at least a portion of a plurality of diamond grains in the second fraction;
the super hard grains in the first fraction having a greater average grain size than the average grain size of the grains in the second fraction, the average grain size of the diamond grains in the second fraction being between around 60 nm to around 1 micron.

### Claim 2 (depends on 1)

The method of claim 1, wherein the step of providing a mass of super hard material comprises providing a mass of natural and/or synthetic diamond grains, the super hard polycrystalline construction forming a polycrystalline diamond (PCD) construction.

### Claim 3

(canceled)

### Claim 4 (depends on 1)

The method of claim 1, further comprising treating the super hard construction to remove at least a portion of residual binder/catalyst from at least a portion of interstitial spaces between interbonded super hard grains.

### Claim 5 (depends on 1)

The method of claim 1, wherein the step of forming a liquid suspension of a first mass of graphene and a mass of particles or grains of super hard material comprises dispersing the graphene and superhard particles or grains in deionized water.

### Claim 6 (depends on 1)

The method of claim 1, wherein the step of forming a liquid suspension of a first mass of graphene and a mass of particles or grains of super hard material comprises dispersing the graphene and superhard particles or grains in an organic solvent.

### Claim 7 (depends on 6)

The method of claim 6, wherein the organic solvent comprises ethanol.

### Claim 8 (depends on 1)

The method of claim 1, wherein the step of forming a liquid suspension further comprises adding a surfactant to the liquid suspension.

### Claim 9 (depends on 8)

The method of claim 8, wherein the surfactant comprises a non-ionic or cationic surfactant.

### Claim 10 (depends on 1)

The method of claim 1, wherein the step of dispersing the graphene and mass of super hard particles or grains in the liquid suspension to form a substantially homogeneous suspension comprises applying to the liquid suspension one or more of:
a sonication process;
an ultrasonic dispersion process;
a homogenization process; and/or a jet milling process.

### Claim 11 (depends on 1)

The method of claim 1, wherein the step of dispersing the graphene and mass of super hard particles or grains in the liquid suspension to form a substantially homogeneous suspension comprises adjusting the pH of the liquid suspension to render the suspension acidic to assist in inhibiting agglomeration or aggregation of the graphene.

### Claim 12 (depends on 1)

The method of claim 1, wherein the step of drying the suspension to form an admix of the graphene and super hard grains or particles comprises one or more of drying the suspension using freeze drying spray freeze drying, spray drying, spray granulation, and/or spray freeze granulation.

### Claim 13 (depends on 1)

The method of claim 1, wherein the graphene has a BET surface area of around 50 m2/g or more, or around 100 m2/g or more, or around 300 m2/g or more, or around 500 m2/g or more.

### Claim 14 (depends on 13)

The method of claim 13, wherein the average grain size of the super hard grains or particles in the admix is around 6 microns or less, or around 4 microns or less, or around 2 microns or less.

### Claim 15

A super hard polycrystalline construction comprising:
a body of polycrystalline super hard material comprising a first fraction of super hard grains and a second fraction of super hard grains, the first fraction having a greater average grain size than the super hard grains in the second fraction;
the super hard grains in the first and second fraction having a peripheral surface;
wherein
the super hard grains in the first fraction are bonded along at least a portion of the peripheral surface to at least a portion of a plurality of super hard grains in the second fraction;
the super hard grains in the second fraction being arranged to space one or more adjacent grains in the first fraction by a distance of between around 60 nm to around 1 micron.

### Claim 16

(canceled)

### Claim 17 (depends on 15)

The super hard polycrystalline construction of claim 15, wherein the body of super hard material comprises inter-bonded super hard grains comprising natural and/or synthetic diamond grains, the super hard polycrystalline construction forming a polycrystalline diamond (PCD) construction.

### Claim 18 (depends on 15)

The super hard polycrystalline construction of claim 15, wherein the PCD construction further comprises a non-super hard phase comprising a binder phase located in interstitial spaces between the inter-bonded diamond grains.

### Claim 19 (depends on 18)

The super hard polycrystalline construction according to claim 18, wherein the binder phase comprises cobalt, and/or one or more other iron group elements, such as iron or nickel, or an alloy thereof, and/or one or more carbides, nitrides, borides, and oxides of the metals of Groups IV-VI in the periodic table.

### Claim at position 20

-22. (canceled)

### Claim 23 (depends on 15)

The super hard polycrystalline construction according to claim 15, wherein at least a portion of the body of super hard material is substantially free of a catalyst material for diamond, said portion forming a thermally stable region.

### Claim 24 (depends on 23)

The super hard polycrystalline construction as claimed in claim 23, wherein the thermally stable region comprises at most 2 weight percent of catalyst material for diamond.

### Claim 25 (depends on 15)

The super hard polycrystalline construction of claim 15, wherein the first fraction comprises a mass of super hard abrasive grains having two or more different average grain sizes.

### Claim at position 24

-33. (canceled)