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CN-122007426-A - Polycrystalline diamond compact and preparation method thereof

CN122007426ACN 122007426 ACN122007426 ACN 122007426ACN-122007426-A

Abstract

The invention relates to a polycrystalline diamond compact and a preparation method thereof, and the polycrystalline diamond compact comprises a boron-containing hard alloy matrix and a polycrystalline diamond layer formed on the boron-containing hard alloy matrix, wherein the polycrystalline diamond layer contains boron elements introduced by the boron-containing hard alloy matrix. When the hard alloy substrate is combined with the polycrystalline diamond layer, boron element can be introduced into the polycrystalline diamond layer through high temperature, and on the premise of ensuring high-quality bonding of diamond, the boron can be uniformly introduced into the diamond layer, so that the thermal damage resistance of the diamond is improved, and the service life of a tool is finally prolonged.

Inventors

  • XU HAORAN
  • LIU BAISHU

Assignees

  • 深圳市海明润超硬材料股份有限公司
  • 中山市海明润超硬材料有限公司

Dates

Publication Date
20260512
Application Date
20260228

Claims (10)

  1. 1. A polycrystalline diamond compact comprises a boron-containing hard alloy matrix and a polycrystalline diamond layer formed on the boron-containing hard alloy matrix, and is characterized in that the polycrystalline diamond layer contains boron introduced by the boron-containing hard alloy matrix.
  2. 2. The polycrystalline diamond compact of claim 1, wherein the boron-containing cemented carbide substrate comprises tungsten carbide, a binder and boron, wherein the mass content of the boron in the boron-containing cemented carbide substrate is 0.001-5%.
  3. 3. The polycrystalline diamond compact of claim 2 wherein the boron element is added as a boron element or/and a boron-containing non-element, the boron-containing non-element being a mixture of one or more selected from the group consisting of boron oxide, boron nitride, boron carbide, cobalt boride, titanium boride and tungsten boride.
  4. 4. The polycrystalline diamond compact of claim 2 wherein the mass content of the binder in the boron-containing cemented carbide substrate is 4-20% and the balance is tungsten carbide.
  5. 5. The boron-containing cemented carbide substrate of claim 4, wherein the binder is a mixture of one or more selected from the group consisting of cobalt, iron and nickel.
  6. 6. The polycrystalline diamond compact of claim 2 wherein the boron element is incorporated into the polycrystalline diamond layer by infiltration of a binder.
  7. 7. The polycrystalline diamond compact of claim 1 wherein the polycrystalline diamond layer is produced by high temperature and high pressure sintering of diamond particles.
  8. 8. The polycrystalline diamond compact of claim 7, wherein the diamond particles have an average particle size ranging from 1 μm to 100 μm.
  9. 9. A method of preparing a polycrystalline diamond compact according to any one of claims 1 to 8, comprising the steps of: (a) Mixing diamond micro powder with different granularities to obtain diamond formula powder; (b) Filling the diamond formula powder into a metal cup, and then placing the boron-containing hard alloy matrix above the diamond formula powder; (c) Sintering the assembly sleeve at 1300-2000 ℃ and under 5-10Gpa to obtain a polycrystalline diamond compact blank, and polishing to obtain the polycrystalline diamond compact.
  10. 10. The method of claim 9, wherein in step (c), the sintering time is 1-30 min.

Description

Polycrystalline diamond compact and preparation method thereof Technical Field The invention belongs to the technical field of superhard materials, and particularly relates to a polycrystalline diamond compact and a preparation method thereof. Background The polycrystalline diamond compact is a composite material formed by pressing diamond micro powder and a hard alloy matrix at high temperature and high pressure, has high hardness, high wear resistance and thermal conductivity of polycrystalline diamond and high strength and impact toughness of hard alloy, and is widely applied to various fields of exploration and drilling of petroleum, natural gas, shale gas and coal fields, high wear resistance bearings, numerical control cutting machining and the like. However, the sintering conditions of polycrystalline diamond are severe, and usually metal binders are added to assist sintering. However, the metal binder has reversibility on the catalysis of diamond-graphite phase transition, so that the composite sheet is easy to change from diamond to graphite in a high-temperature environment of actual use. And boron element is introduced into the diamond, so that the high-heat-resistant polycrystalline diamond compact with anti-graphitization tendency can be prepared, and the thermal damage to the diamond during working is reduced, thereby prolonging the working life and improving the drilling efficiency. The existing method generally selects to directly mix the boron simple substance or the boron-containing compound into the diamond micro powder, however, the method has obvious defects that (1) the boron is difficult to uniformly disperse in the micro powder and is easy to cause uneven local performance, and (2) the boron directly attached to the surface of the diamond particles can physically obstruct the direct contact between the diamond micro powder, thereby generating steric hindrance, weakening the bond formation between the diamond micro powder and affecting the integral bonding strength and the wear resistance of the composite sheet. Disclosure of Invention In order to solve the technical problems, the invention aims to provide a polycrystalline diamond compact. In order to achieve the purpose, the technical scheme adopted by the invention is that the polycrystalline diamond compact comprises a boron-containing hard alloy matrix and a polycrystalline diamond layer formed on the boron-containing hard alloy matrix, wherein the polycrystalline diamond layer contains boron elements introduced by the boron-containing hard alloy matrix. Optimally, the boron-containing hard alloy matrix comprises tungsten carbide, a binder and boron, wherein the mass content of the boron in the boron-containing hard alloy matrix is 0.001-5%. Further, the boron element is added in the form of boron simple substance or/and boron-containing non-simple substance, and the boron-containing non-simple substance is a mixture of one or more selected from boron oxide, boron nitride, boron carbide, cobalt boride, titanium boride and tungsten boride. Further, the mass content of the binder in the boron-containing hard alloy matrix is 4-20%, and the balance is the tungsten carbide. Still further, the binder is a mixture of one or more selected from the group consisting of cobalt, iron and nickel. Further, the boron element is introduced into the polycrystalline diamond layer by infiltration of a binder. Optimally, the polycrystalline diamond layer is prepared by sintering diamond particles at high temperature and high pressure. Further, the average particle diameter of the diamond particles is in the range of 1-100 μm. Still another object of the present invention is to provide a method for preparing the polycrystalline diamond compact, including the steps of: (a) Mixing diamond micro powder with different granularities to obtain diamond formula powder; (b) Filling the diamond formula powder into a metal cup, and then placing the boron-containing hard alloy matrix above the diamond formula powder; (c) Sintering the assembly sleeve at 1300-2000 ℃ and under 5-10Gpa to obtain a polycrystalline diamond compact blank, and polishing to obtain the polycrystalline diamond compact. Optimally, in the step (c), the sintering time is 1-30 min. Due to the application of the technical scheme, the polycrystalline diamond compact has the advantages that the polycrystalline diamond layer contains boron element introduced by the boron-containing hard alloy matrix, so that the boron element can be introduced into the polycrystalline diamond layer through high temperature when the hard alloy matrix is combined with the polycrystalline diamond layer (such as by preferably utilizing the infiltration effect of a liquid bonding phase during high-temperature and high-pressure synthesis), and the boron can be uniformly introduced into the diamond layer on the premise of ensuring high-quality bonding of diamond, thereby improving the thermal damage resistance of the di