Polycrystalline diamond composite sheet and its preparation method

Abstract

The invention provides a polycrystalline diamond composite sheet and a preparation method thereof. The preparation method of the diamond composite sheet includes a pre-pressing forming step, and the pre-pressing forming step includes placing diamond micropowder in a metal round cup, and pressing the metal round cup through a briquetting block. The diamond powder inside is pre-pressed, and the diamond powder forms a preformed body of the working layer. The pressing end of the pressing block is provided with an outer chamfer along the circumferential direction of the pressing block. The diamond micropowder is pre-pressed, and the formed working layer preform has a protrusion corresponding to the position of the outer chamfer, which increases the amount of micropowder at the edge of the diamond composite sheet, improves the density at the edge, and increases the density of the diamond composite sheet. The working area is large, and the thickness of the preform of the working layer is uniform, which improves the stability of production and the overall performance of the diamond composite sheet.

Description

technical field [0001] The invention relates to the field of superhard composite materials, in particular to a polycrystalline diamond composite sheet and a preparation method thereof. Background technique [0002] Diamond compact drill bits (PDC drill bits) are widely used in oil and natural gas drilling. With the gradual reduction of conventional oil and natural gas exploitation resources, vigorously developing shale oil and shale gas is a major trend in the future. Shale oil, etc. Difficult mining geology has higher and higher performance requirements for PDC drill bits. [0003] The diamond composite sheet is sintered together with diamond powder and cemented carbide substrate (tungsten carbide layer) under high temperature and high pressure, and the diamond powder is sintered into a polycrystalline diamond layer, so that the composite sheet has the ultra-high hardness and wear resistance of diamond, hard The high quality alloy matrix has weldability, which is convenien...

AI Technical Summary

Problems solved by technology

see Figure 4 and Figure 5 , after the same number of turnings, the size of the ground area of ​​the four positions is obviously inconsistent by visual inspection. It can be seen that the thicknesses of the polycrystalline layer 1 and the transition layer 2 of the diamond compact prepared by this preparation method are uneven. The phenomenon of homogeneity leads to large differences in the performance of different parts of the same composite sheet, making the wear resistance and impact resistance of the polycrystalline layer on the diamond composite sheet relatively weak, making the service life of the diamond composite sheet short

Images