Diamond coating drill bit and preparation method thereof

Abstract

The invention relates to a diamond coating drill bit and a preparation method thereof. The drill bit comprises a drill body (1) and a drill tip (2); the drill body (1) is coated with a carbon base coating layer such as a nanocrystalline diamond coating layer or a diamond-like coating layer; and the drill tip (2) is coated with a micron crystalline diamond coating layer. A heat stop cylinder is arranged on a heat wire chemical vapor deposition device; and the coating layers are obtained by using chemical vapor deposition. The drill tip and the drill body are respectively coated with the microncrystalline diamond coating layer and the carbon base coating layer with low friction coefficient such as the nanocrystalline diamond coating layer or the diamond-like coating layer; excellent wear resistance of the micron crystalline diamond coating layer and excellent chip discharge performance of the nanocrystalline diamond coating layer are fused to obtain the diamond coating drill bit with excellent wear resistance and chip discharge performance; the working efficiency of the drill bit is improved; the service life is prolonged; and excellent application prospect is achieved.

Description

technical field [0001] The invention relates to the field of mechanical processing and manufacturing, in particular to a diamond-coated drill bit and a preparation method thereof, in particular to a drill bit whose drill body and drill tip are coated with diamond coatings of different grain sizes and a preparation method thereof. Background technique [0002] At present, high-speed steel cutting tools, physical vapor deposition (PVD) and chemical vapor deposition (CVD) coated carbide cutting tools, ceramic cutting tools and polycrystalline diamond / polycrystalline boron nitride (PCD / PCBN) cutting tools due to low hardness or cutting tool shape Limited and other reasons can not fully meet the high-speed, high-efficiency processing of composite materials, A1Si non-ferrous alloys and special graphite and other material processing requirements. CVD diamond-coated cemented carbide has high hardness and can be deposited on tools with complex structures, becoming the best tool mater...

AI Technical Summary

Problems solved by technology

[0008] Drills coated with microcrystalline diamond coating have excellent wear resistance when processing difficult-to-cut materials such as CFRP, high-Si Al alloys, graphite, and zirconia ceramics, but the chip discharge resistance is relatively large, so chips are easy to clog. Easy to cause tool breakage or decrease in drilling quality

However, if the surface of the drill bit is coated with a smooth nanocrystalline diamond coating, although the problem of chip removal of the coated drill bit is solved, there is a problem of poor wear resistance, and it is difficult to achieve a long service life.

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