Method for depositing polycrystalline diamond clad sheet of CVD diamond coating at low temperature

A technology of polycrystalline diamond and diamond coating, which is applied in metal material coating technology, coating, metal processing equipment, etc., and can solve the problems of high drill replacement costs and reduced drill life

CN112695293APending Publication Date: 2021-04-23TONGJI UNIV
8 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2021-04-23

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention relates to a method for depositing a polycrystalline diamond clad sheet of a CVD diamond coating at a low temperature. The method comprises the following steps that (1), a polycrystalline diamond clad sheet substrate is prepared; (2), vacuumizing is conducted on a reaction chamber of a chemical vapor deposition device, mixed gas composed of hydrogen and methane is introduced, and nucleation treatment is conducted; (3), the polycrystalline diamond clad sheet substrate is put into the reaction chamber, mixed gas composed of hydrogen, methane and carbon dioxide is introduced, and chemical vapor deposition is carried out; and (4), after deposition is completed, the methane and the carbon dioxide are closed, the hydrogen flow is kept unchanged, and etching treatment is conducted to obtain the polycrystalline diamond clad sheet deposited with the CVD diamond coating at the low temperature. Compared with the prior art, the method has the advantages that the failure of the polycrystalline diamond clad sheet due to the graphitization promotion effect of a catalyst under high-temperature and high-pressure conditions and the difference of high-temperature thermal expansion coefficients can be avoided, so that the service life of the polycrystalline diamond clad sheet is prolonged, and the drill replacement frequency is reduced.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention belongs to the technical field of material coating, and relates to a method for low-temperature deposition of a CVD diamond coating polycrystalline diamond composite sheet. Background technique

[0002] Diamond coating is a new type of functional material in the 21st century. It has high strength, high friction and wear performance, high thermal conductivity and chemical stability, and has broad application prospects. At present, the recognized diamond coating deposition method is mainly chemical vapor deposition (Chemical Vapor Deposition, CVD). However, the main problem limiting the industrialization of diamond coating technology is the lack of toughness of the coating, which makes the coating and the substrate easy to fall off.

[0003] The diamond wear of diamond drill bits can be divided into brittle fracture, abrasive wear, thermal wear and threshing. First, the bonded metal in the carcass is worn, because the hardness and wear res...

Examples

Embodiment 1

[0047] A method for low-temperature deposition of a CVD diamond coating based on an improved substrate formula polycrystalline diamond compact, comprising the following steps:

[0048] (1) Improved polycrystalline diamond composite substrate formula

[0049] Change the base formula of the polycrystalline diamond composite sheet. According to the mass parts, the ratio of diamond powder to metal alloy is 4:1, wherein, diamond powder: 25 / 30 mesh (that is, 25-30 mesh, the same below) and 40 / 50 mesh ( That is, 40-50 mesh) mixed, and 25 / 30:40 / 50=1:1 (mass ratio, the same below); the metal alloy contains 50wt% of WC, 7wt% of Co, and 28wt% of Cu , containing Sn as 15wt%. The polycrystalline diamond powder and cemented carbide powder are directly placed in the mold, and the powder metallurgy method is used to sinter at 5GPa, 1200°C, the holding time is 15min, the temperature is lowered to 800°C, and the furnace is air-cooled to room temperature.

[0050] (2) CVD diamond coating depos...

Embodiment 2

[0058] A method for low-temperature deposition of a CVD diamond coating based on an improved substrate formula polycrystalline diamond compact, comprising the following steps:

[0059] (1) Improved polycrystalline diamond composite substrate formula

[0060] Change the base formula of the polycrystalline diamond composite sheet. According to the mass parts, the ratio of diamond powder to metal alloy is 4:1, wherein, diamond powder: 25 / 30 mesh (that is, 25-30 mesh, the same below) and 40 / 50 mesh ( That is, 40-50 mesh) mixed, and 25 / 30:40 / 50=1:1 (mass ratio, the same below); the metal alloy contains 54wt% of WC, 6wt% of Co, and 30wt% of Cu , containing Sn as 10wt%. The polycrystalline diamond powder and cemented carbide powder are directly placed in the mold, and the powder metallurgy method is used to sinter at 5GPa, 1100°C, the holding time is 10min, the temperature is lowered to 800°C, and the furnace is air-cooled to room temperature.

[0061] (2) CVD diamond coating depos...

Embodiment 3

[0069] A method for low-temperature deposition of a CVD diamond coating based on an improved substrate formula polycrystalline diamond compact, comprising the following steps:

[0070] (1) Improved polycrystalline diamond composite substrate formula

[0071] Change the base formula of the polycrystalline diamond composite sheet. According to the mass parts, the ratio of diamond powder to metal alloy is 4:1, wherein, diamond powder: 25 / 30 mesh (that is, 25-30 mesh, the same below) and 40 / 50 mesh ( That is, 40-50 mesh) mixed, and 25 / 30:40 / 50=1:1 (mass ratio, the same below); the metal alloy contains 58wt% of WC, 3wt% of Co, and 34wt% of Cu , containing Sn as 5wt%. The polycrystalline diamond powder and cemented carbide powder are directly placed in the mold, and the powder metallurgy method is used to sinter at 5GPa, 1000°C, the holding time is 5min, the temperature is lowered to 800°C, and the furnace is air-cooled to room temperature.

[0072] (2) CVD diamond coating deposit...