Carbon dioxide laser processing method and processing device for pcbn

Abstract

The invention relates to a carbon dioxide laser machining method of PCBN. The surface of a material is cut by utilizing laser, and the generated temperature gradient in the cutting process results inphase change of cubic boron nitride to hexagonal boron nitride, so that great thermal stress and internal stress are caused, and the material produces cracks and propagating cracks in the kerf direction. The machining method is totally different from the traditional laser machining principle; the PCBN laser cutting efficiency is improved effectively; and the forming areas of a heat-affected zone and a recasting layer of the material are reduced, and the roughness of the machined surface is improved.

Description

technical field [0001] The invention belongs to the field of processing hard and brittle materials, and relates to processing PCBN by laser, in particular to a carbon dioxide laser processing method and processing device for PCBN. Background technique [0002] Polycrystalline cubic boron nitride (Polycrystalline Cubic Boron Nitride) referred to as PCBN is another new type of superhard synthetic material after artificial diamond. PCBN is a cubic boron nitride single crystal with or without various binders (phases) and then processed Isotropic polycrystalline block formed by high temperature and high pressure polymerization and sintering. Due to its high hardness, diamond tools have always been of high application value in high-speed cutting, but their chemical properties are unstable, and they are prone to chemical reactions with iron and other metals to cause tool breakage, and the cost is relatively high. The hardness of PCBN is second only to diamond. Unlike diamond, its ...

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Problems solved by technology

[0006] It can be seen from Table 1 that the diamond grinding wheel cutting method is simple, but the processing quality is poor and the product qualification rate is low; the high-pressure water jet will cause a lot of water pollution during the cutting process, the cost of mechanical maintenance is high, and the cutting efficiency is low; the efficiency of ultrasonic cutting is often lower. Low is generally not used; therefore these three processing methods have been gradually replaced by the latter two processing methods

The cutting of PCBN by wire electric discharge cutting is adopted by most cutting tool manufacturers. Since the hard particles contained in PCBN sheets are not conductive, wire electric discharge cutting is difficult and easy to break.

Later, some scientists at home and abroad have improved the machinability of WEDM by adding conductive additives and increasing the pressure in the PCBN sintering process, but it can only achieve small batch production and production, and material removal Low rate, relatively wide incision, poor surface quality, most PCBNs at home and abroad still cannot be processed; laser cutting highlights the advantages of high processing efficiency and good cutting quality in PCBN processing

However, there are also some problems, such as the formation of a recast layer, the need for secondary grinding of the cut, and the low material removal rate

Therefore, there are problems such as long processing time, high energy consumption, and low efficiency in the current PCBN processing method.

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