Preparation method of diamond coating layer, prepared diamond coating layer and cutter

Abstract

The invention discloses a preparation method of a diamond coating layer, the prepared diamond coating layer and a cutter, and relates to the technical field of diamond films. The preparation method ofthe diamond coating layer comprises the steps that nanometer diamond suspension is used for planting crystals on a basal body with positive / negative charges on the surface, and a heater chemical vapor deposition method is used for growing diamonds to obtain the diamond coating layer; and the electricity of nanometer diamond particles in the nanometer diamond suspension is opposite to the chargeson the surface of the basal body. Through the electrostatic absorption crystal planting mode, the nanometer diamond particles dispersed in the solution are absorbed on a basal body structural part; through the mode, the absorption density of the nanometer diamond particles on the basal body can be greatly increased; the high-density nucleation is realized on the surface of the basal body; and thegrown diamond coating layer is high in adhesion, long in service life, low in roughness and high in precision. The cutter deposited with the coating layer is long in cutting life and high in machiningprecision.

Description

technical field [0001] The invention relates to the technical field of diamond thin films, in particular to a method for preparing a diamond coating and the prepared diamond coating and cutting tool. Background technique [0002] With the rapid development of industry, lightweight and high-strength materials have gradually become the mainstream. New materials such as non-ferrous metals and alloys, glass fiber reinforced plastics, graphite and ceramics are widely used in industry. Ordinary high-speed steel and hard alloy Tools are not up to the task of mechanically cutting these materials. At the same time, with the advent of modern integrated system machining centers, mobile machining workshops, and computer integrated manufacturing systems, machining is developing in the direction of high-precision, high-speed, and high-productivity cutting. high demands. Therefore, the development of various superhard cutting tools with superior cutting performance is an inevitable trend...

AI Technical Summary

Problems solved by technology

However, the temperature required for hot wire chemical vapor deposition is relatively high. After the diamond film is prepared by this method, in the process of cooling to room temperature, due to the large difference in thermal expansion coefficient between the diamond film and the cemented carbide tool, it is easy to produce thermal stress. The resulting film-base interface bonding force is poor, and cracks are formed at the interface, which makes the diamond film easy to fall off during the cutting process

During the cutting process, the ratio of the failure of the film due to the shedding of the diamond film to the end of the tool life due to wear is about 10:1. It can be seen that the adhesion between the film and the tool seriously affects the life of the tool.

[0005] Most of the existing technologies use the method of intermediate layer or multi-layer film to alleviate the coating peeling caused by thermal stress

Patent CN101880866A discloses a method for preparing a diamond-silicon carbide-cobalt silicide composite intermediate layer for diamond coating on cemented carbide. The thermal expansion coefficient of silicon carbide in the composite intermediate layer prepared by this method is 5×10 -6 -7×10 -6 / K, and the coefficient of thermal expansion of diamond 1×10 -6 -2×10 -6 / K still has a large difference, and it cannot solve the nucleation density of diamond in the composite layer

Patent CN106835133A discloses a workpiece with a titanium diboride-diamond composite coating and its preparation method. The method uses titanium diboride as the intermediate layer between the hard alloy and the diamond film to block the formation of Co in the hard alloy. Diffusion can increase the nucleation density of diamond film, but the thermal expansion coefficient of titanium diboride is higher than that of diamond film and cemented carbide, so it is not very suitable as an intermediate layer for relieving thermal stress, and can only be used as an outer layer of Co in cemented carbide. diffusion barrier

Patent CN105483644A discloses a multi-layer diamond coating and its preparation method, coating tool, which grows micro-diamond, nano-diamond and ultra-fine nano-diamond coatings on the surface of the substrate in sequence, so as to relieve thermal stress and improve coating The bonding force between the layer and the substrate, but the diamond film prepared by this method is complicated and costly, and it needs to be deposited three times, and the quality of the diamond film is likely to decline during the process of changing parameters, resulting in many layers between layers. defect

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