Superhard Cutting Tools Considered to Improve Productivity Significantly

With the increasing of precision machinery and difficult-to-machine materials, the application of superhard cutting tools have become gradually widely. Superhard cutting tools have high cutting properties, long service life and good workpiece quality, etc. Firstly it is mainly used in laser machining process, but with the development of scientific research in recent years, some researchers have improved the production technology of artificial superhard cutting tools, controlled the purity of raw materials and grain size, and adopted composite materials and hot pressing technology, etc., which make superhard cutting tools gradually applied to semi-finishing and roughing process. Therefore it is internationally recognized as the one of the most promising tools to improve productivity at present.

Superhard cutting tools are divided into diamond cutting tools and cubic boron nitride cutting tools. Because the prices of natural diamonds are more expensive, the diamond tools used in the processing are synthetic polycrystalline diamond (PCD), polycrystalline cubic boron nitride (PCBN), and their composite materials.

It was firstly used that in the 1950s, the United States had used synthetic diamond powder and artificial CBN powder at high temperature and high pressure, and the action of catalyst and bond to sinter larger polycrystalline blocks as cutting tool materials. The research and application of superhard cutting tools in China started in the 1970s, and in 1970, we built firstly a professional manufacturer about superhard materials and products in Guiyang. By 1997, the annual capacity of synthetic diamonds has achieved 500 million carat or so in our country, and CBN annual output of 8 million carats, becoming first of superhard materials production countries in the world.

Diamond has extremely high hardness and wear resistance, and is the most hard materials of cutting tool materials. It has high thermal conductivity and no affinity with nonferrous metals, and is not easy to produce the built-up edge when cutting and has great processing surface quality. It can be used to process effectively non-ferrous metals and non-metallic materials, such as copper, aluminum and other non-ferrous metals and their alloys, ceramics, plastics, rubber, etc.

Someone may ask that since the performance of diamond and cubic boron nitride is almost equal, they will cause conflict? The answer is no. Because although diamond has high hardness, good wear resistance, but poor toughness, thermal stability, and is easily carbonized under the temperature of 700 ℃ to 800 ℃, so it is not suitable for processing steel material (black metal). But cubic boron nitride is the contrary, whose hardness is only second to diamond, but has great thermal stability, and can process normally under high temperature (1250 ℃-1350 ℃). It is suitable for processing all kinds of high hardness steel materials, such as hardened steel gears, bearings, cast iron roll, pump and other hard processing materials.