Circular-arch-shaped polycrystalline diamond composite sheet preparing method

Abstract

The invention discloses a circular-arch-shaped polycrystalline diamond composite sheet preparing method. The circular-arch-shaped polycrystalline diamond composite sheet preparing method comprises thesteps that firstly, hard alloy base body purification treatment is conducted; secondly, a transition layer is deposited on the surface of a hard alloy base body; thirdly, ion implantation of diamondis conducted; fourthly, material mixing is conducted; fifthly, composite body assembling is conducted; sixthly, composite body purification is conducted; and seventhly, high-temperature high-pressuresintering is conducted. N<+> and B<+> are injected into the surface of the diamond through the ion beam injection technology, structure defects existing in the ordinary diamond particle surface are overcome, performance compatibility is improved, and heat stability and abrasion resisting performance of a polycrystalline diamond composite sheet are improved. Meanwhile, the chemical vapor depositiontechnology is utilized for sequentially depositing a silicon carbide layer and a silicon carbide-diamond gradient composite layer on the hard alloy surface, stress between the polycrystalline diamondlayer and the hard alloy base body is reduced, and the bonding strength of the polycrystalline diamond layer and the hard alloy base body is improved.

Description

technical field [0001] The invention belongs to the technical field of superhard materials, and in particular relates to an arched polycrystalline diamond composite sheet and a preparation method thereof. Background technique [0002] Polycrystalline diamond composite sheet is a superhard composite material composed of polycrystalline diamond layer and cemented carbide matrix. Because this product combines the advantages of both polycrystalline diamond and cemented carbide, and the polycrystalline diamond layer can always keep sharp Therefore, it is widely used in geological and oil drilling, and has achieved very good results in soft to medium hard rock formations. [0003] Although bonding the polycrystalline diamond layer and the cemented carbide substrate can combine the advantages of these two materials in a single product, due to the inherent differences in the properties of the two materials, their interface becomes the In the most fragile area, during the high tempe...

AI Technical Summary

Problems solved by technology

[0003] Although bonding the polycrystalline diamond layer and the cemented carbide substrate can combine the advantages of these two materials in a single product, due to the inherent differences in the properties of the two materials, their interface becomes the In the most fragile area, during the high temperature and high pressure sintering process, the physical performance parameters such as thermal expansion coefficient and elastic modulus of the polycrystalline diamond layer and the cemented carbide substrate are quite different, so there is inevitably serious thermal residual stress at the interface. As a result, the adhesion between polycrystalline diamond and cemented carbide substrate is not strong, the impact resistance is poor, and interface cracks are easily formed, resulting in the polycrystalline diamond layer being easy to fall off and break during work, resulting in failure of the drill bit

At present, the traditional flat-tooth and special-shaped diamond composite sheets (such as shallow concave PDC, conical PDC and roof-shaped PDC, etc.) on the market are weak in the application of deep complex hard rock formations, frequent tooth chipping and lower drilling. The drilling efficiency seriously affects the development of drilling technology

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