Sintering method of polycrystalline diamond (PCD) material

Abstract

The invention discloses a sintering method of a polycrystalline diamond (PCD) material. The sintering method comprises the following steps: performing acid and alkali purification treatment on diamond particles, uniformly mixing with a bonder, and performing process sintering treatment in a high-temperature vacuum furnace, wherein the sintering treatment process is carried out under the condition that the pressure (P) is more than 5.7GPa and less than 5.9GPa, the temperature (T) is more than 1,550 DEG C and less than 1,570 DEG C, and the sintering time is more than 3 minutes and less than 5 minutes. According to the sintering method, the polycrystalline diamond material is subjected to high-temperature high-pressure sintering under the specific pressure, temperature and process duration time, a remarkable D-D combined network-shaped framework structure is formed between the bonder and the diamond particles, and bonding phases are uniformly distributed in a star point or catkin shape at the triple grain boundary junction of the diamond particles, which shows that the sintering process is relatively good and the PCD material with uniform overall performance and fine granularity is basically prepared.

Description

technical field [0001] The technical field of diamond material processing of the present invention, in particular, relates to a sintering method of polycrystalline diamond material. Background technique [0002] Polycrystalline diamond (also known as polycrystalline diamond, PCD) is a superhard material (also known as superabrasive). Polycrystalline diamond is made by powder sintering under ultra-high pressure and high temperature conditions by mixing many fine-grained diamonds or diamonds with a certain proportion of binder. [0003] The PCD material may comprise at least about 80 vol% diamond and may be prepared by subjecting an aggregate of diamond particles to an ultrahigh pressure of greater than about 5 GPa and a temperature of at least about 1200° C. in the presence of a diamond catalyst material, The diamond catalyst material is a material that can promote direct co-growth of diamond particles under pressure and temperature where diamond is thermodynamically more st...

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Problems solved by technology

[0005] However, the applicant's experiments have proved that when cobalt is used as the binder, when the sintering temperature is 1400°C or even 1450°C, although the sintering temperature exceeds the carbon-cobalt eutectic temperature of 1336°C, due to the small degree of superheat, the cobalt liquid Diffusion in fine-grained diamond powder is hindered, and most of the diamond particles in the sintered sample are in an "isolated" state, which does not form a good D-D bond, and due to the difference in the particle size of the diamond powder, the distribution of the binder on the outer surface of the diamond powder Not uniform, the overall mechanical properties of the sintered polycrystalline diamond material are poor

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