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CN-116330801-A - Preparation method of polycrystalline diamond compact

CN116330801ACN 116330801 ACN116330801 ACN 116330801ACN-116330801-A

Abstract

The invention relates to a preparation method of a polycrystalline diamond compact, wherein main-granularity diamond particles and auxiliary-granularity diamond particles are soaked by strong acid and strong alkali, and pure water is repeatedly cleaned; performing sand blasting treatment on the hard alloy matrix; mixing the main and auxiliary diamond particles in a mixer; the mixed diamond particles and the hard alloy matrix are filled into a high-temperature-resistant metal cup; placing the metal cup into a synthetic block and placing into a hexahedral top press; performing three-stage high-pressure two-stage high-temperature sintering, wherein the first stage high-pressure is performed, the cold state pressurization is performed to 6.5-8.2 GPa, and the second time is maintained for 30-60 seconds; the second stage is heated at high pressure, the sintering pressure is 6-8 GPa, the sintering temperature is 1490-1580 ℃, and the sintering time is maintained for 300-600 seconds; the third section is heated at high pressure and 5.0-6.0 GPa, the temperature is 1150-1250 ℃, and the temperature is maintained for 150-200 seconds; reducing the pressure and cooling to normal pressure and room temperature to obtain the polycrystalline diamond compact blank. After sintering, the fine particles are uniformly distributed around the coarse particles.

Inventors

  • JIANG YUMING
  • HUANG ZHIYU
  • HUANG HUIBIN
  • HE SHUILIANG
  • XIANG JINXING

Assignees

  • SUZHOU SIPOLIER INDUSTRIAL TECH CO LTD

Dates

Publication Date
20230627
Application Date
20230331
Priority Date
20230331

Claims (8)

  1. 1. The preparation method of the polycrystalline diamond compact is characterized by comprising the following steps: soaking the diamond particles with main granularity and the diamond particles with auxiliary granularity in strong acid and strong alkali, and repeatedly cleaning with pure water to remove impurities; carrying out sand blasting treatment on the hard alloy matrix; mixing the treated main-granularity diamond particles and auxiliary-granularity diamond particles in a mixer; sequentially filling the mixed diamond particles and the hard alloy matrix into a high-temperature-resistant metal cup, and covering the cup; the metal cup is put into a synthetic block and is put into a hexahedral top press; performing three-stage high-pressure two-stage high-temperature sintering, wherein the first stage high-pressure is pressurized to 6.5-8.2 GPa in a cold state, and the second time is maintained for 30-60 seconds; the second stage is heated at high pressure, the sintering pressure is 6-8 GPa, the sintering temperature is 1490-1580 ℃, and the sintering time is maintained for 300-600 seconds; the third section is heated at high pressure and 5.0-6.0 GPa, the temperature is 1150-1250 ℃, and the temperature is maintained for 150-200 seconds; and then reducing the pressure and cooling to normal pressure and room temperature to obtain the polycrystalline diamond compact blank.
  2. 2. A method of preparing a polycrystalline diamond compact according to claim 1, wherein: after being soaked by strong acid and strong alkali and repeatedly cleaned by pure water, the surface impurity content of the diamond particles with main granularity and the diamond particles with auxiliary granularity is less than 70ppm.
  3. 3. A method of preparing a polycrystalline diamond compact according to claim 1, wherein: the mixing proportion of the diamond particles is 65-95 wt% of the diamond particles with main granularity and 5-35 wt% of the diamond particles with auxiliary granularity.
  4. 4. A method of preparing a polycrystalline diamond compact according to claim 1 or 3, wherein: the main granularity diamond particles have the particle size of 8-40 um and the particle shape of block or nearly sphere.
  5. 5. A method of preparing a polycrystalline diamond compact according to claim 1 or 3, wherein: the diameter of the diamond particles with the auxiliary particle size is 8-40 um, and the shape of the diamond particles is strip-shaped or sheet-shaped.
  6. 6. A method of preparing a polycrystalline diamond compact according to claim 1, wherein: the high-temperature resistant metal cup is made of Zr, mo, nb or Ta.
  7. 7. A method of preparing a polycrystalline diamond compact according to claim 1, wherein: the hard alloy matrix is made of W-Co alloy, and the Co content is 10-18 wt%.
  8. 8. A method of preparing a polycrystalline diamond compact according to claim 1 or 3, wherein: the diamond particles with main granularity and the diamond particles with auxiliary granularity are mixed in a mixer for 4 to 8 hours.

Description

Preparation method of polycrystalline diamond compact Technical Field The invention relates to a preparation method of a polycrystalline diamond compact, and belongs to the technical field of superhard material preparation. Background At present, the polycrystalline diamond compact consists of a diamond working layer and a hard alloy matrix, wherein the diamond working layer is formed by sintering innumerable diamond particles under the conditions of high temperature and high pressure through the catalysis of a metal catalyst Co. Polycrystalline diamond compacts are used in oil and gas drilling, and the polycrystalline diamond compacts used in the industry are standardized in size, and have the main specifications of diameter and height (unit mm): Φ13.44×13.2, Φ15.88×13.2, Φ19.05×13.2, etc., wherein the thickness of the diamond working layer is 1.2-2.5 mm. The polycrystalline diamond compact has the characteristics of high hardness and super wear resistance of diamond, and has high impact resistance of hard alloy, and meanwhile, the hard alloy can provide better weldability, so that the diamond compact is firmly welded on a diamond bit body in engineering. With the continuous development of petroleum and natural gas drilling to deeper earth, the drilling depth is continuously increased from 2000-3000 m to 4000-5000 m, the deeper the depth is, the more complex the geological environment is, the more severe the hardness, the abrasive property and the impact property of the stratum are, and the higher requirements are put on various performance indexes of the polycrystalline diamond compact. In order to pursue high performance, it is necessary to increase the diamond ratio in the diamond working layer, and because of the particle shape, the voids between the diamond particles should be filled with finer diamond particles as much as possible to obtain the highest possible diamond ratio. The addition of fine-grain diamond brings two unavoidable negative effects to the manufacture of the polycrystalline diamond compact, namely, in the stage of batching and mixing, the fine-grain diamond is difficult to be uniformly mixed with coarse-grain diamond, and the fine grains are easy to aggregate, so that the performance of a sintered diamond working layer is unstable; secondly, the specific surface area of the fine-grain diamond particles is far larger than that of the coarse particles, the surface area of the particles can adsorb impurities such as oxygen, moisture and the like in the air, and the impurities can seriously obstruct the effect of the catalyst Co, so that the high-temperature high-pressure sintering process is unsmooth, and the yield of the sintering process is reduced. Therefore, improvement is needed to be carried out on the existing preparation method of the polycrystalline diamond compact, and a new research thought is provided in particular to overcome the negative effects of the fine-grain diamond. Disclosure of Invention The invention aims to overcome the defects in the prior art and provide a preparation method of a polycrystalline diamond compact, and the prepared polycrystalline diamond compact can better meet the use requirements of petroleum and natural gas drilling and is more suitable for drilling tasks of deeper stratum. The aim of the invention is achieved by the following technical scheme: the preparation method of the polycrystalline diamond compact is characterized in that: soaking the diamond particles with main granularity and the diamond particles with auxiliary granularity in strong acid and strong alkali, and repeatedly cleaning with pure water to remove impurities; carrying out sand blasting treatment on the hard alloy matrix; mixing the treated main-granularity diamond particles and auxiliary-granularity diamond particles in a mixer; sequentially filling the mixed diamond particles and the hard alloy matrix into a high-temperature-resistant metal cup, and covering the cup; the metal cup is put into a synthetic block and is put into a hexahedral top press; performing three-stage high-pressure two-stage high-temperature sintering, wherein the first stage high-pressure is pressurized to 6.5-8.2 GPa in a cold state, and the second time is maintained for 30-60 seconds; the second stage is heated at high pressure, the sintering pressure is 6-8 GPa, the sintering temperature is 1490-1580 ℃, and the sintering time is maintained for 300-600 seconds; the third section is heated at high pressure and 5.0-6.0 GPa, the temperature is 1150-1250 ℃, and the temperature is maintained for 150-200 seconds; and then reducing the pressure and cooling to normal pressure and room temperature to obtain the polycrystalline diamond compact blank. Further, according to the preparation method of the polycrystalline diamond compact, after being soaked by strong acid and strong alkali and repeatedly cleaned by pure water, the surface impurity content of the main granularity diamond particles and the auxiliary