Polycrystal diamond hard alloy complex sheet of surface groove with lack Co area

Abstract

The invention discloses a carbide composite tablet of polycrystalline diamond with Co deficient areas and a grooved surface, which includes a carbide layer and a polycrystalline diamond layer; the carbide layer consists of a carbide (usually adopting tungsten carbide: WC) and a bonding agent (usually adopting Co), and a polycrystalline diamond layer consists of a diamond and a catalytic binder (usually adopting Co). The surface of the diamond is engraved with grooves, wherein, the engraved grooves divide the diamond layer into a plurality of platforms. Through the process of removing Co, Co deficient areas are formed on the engraved grooves or the platforms of the polycrystalline diamond layer or on both. The carbide composite tablet of polycrystalline diamond of the invention is increased by 1-2 times in abrasion ratio; under the same size of impact force, the break-off area of the diamond layer can be reduced by 50 to 80 percent, and the composite tablet of the invention can greatly improve the use temperature of carbide composite tablet of polycrystalline diamond, and the use temperature can be improved to at least 100 DEG C, thus enlarging the scope of use temperature and enabling the composite tablet to be used under higher abrasion speed.

Description

Technical field: [0001] The invention relates to the field of superhard materials, in particular to a polycrystalline diamond cemented carbide composite sheet with grooves on the surface of a Co-deficient region for oil drilling and other drilling. Background technique: [0002] Polycrystalline diamond cemented carbide composite sheet is composed of polycrystalline diamond layer on the surface and tungsten carbide cobalt cemented carbide layer on the bottom layer under high temperature and high pressure. The diamond layer generally contains 80-95vol% diamond and 5-20vol% catalytic bonding Material composition, the most commonly used catalytic bonding material is cobalt (Co). Generally speaking, the reduction of Co content can improve the wear resistance of the composite sheet; the important role of Co in the synthesis of the composite sheet is to promote the sintering of diamond powder and The diamond powder forms a continuous whole, while Co is embedded between the diamond ...

AI Technical Summary

Problems solved by technology

However, due to the large difference between the thermal expansion coefficient of Co and diamond, if the temperature exceeds 400 ° C, it may cause cracks and cracks in the composite sheet; and when the temperature exceeds 750 ° C, due to the catalytic effect of Co, diamond will begin to graphitize and make Composite sheet failure

[0003] In order to solve this problem and obtain a "thermally stable" polycrystalline diamond carbide composite sheet, the researchers proposed the following methods: use Si instead of Co, form SiC without catalytic effect during the synthesis process, and improve the "thermal stability" performance Use the carbonate of Mg, Ca, Sr and Ba; U.S. Patent (US 4224380) discloses a kind of method that Co is extracted from the diamond layer that the relative density of diamond is less than 80%, but if the relative density of diamond is greater than 80% , this method is not easy to extract Co

There are more or less problems in these methods, and they cannot completely improve the thermal stability of the composite sheet without losing other properties.

Images