Introduction and history of ceramic knife(2)

Background to the emergence of ceramic tools:

A tool is a tool used in mechanical engineering for cutting and machining, also known as a cutting tool. Broadly speaking, cutting tools include both tools and abrasives. The vast majority of tools are for machine use, but they are also used by hand. As the tools used in mechanical engineering are basically used for cutting metal materials, the term "tool" is generally understood to mean a metal cutting tool. Tools used for cutting wood are called woodworking tools.

The development of cutting tools has played an important part in the history of human progress. In China, brass cones and bronze cones, drills and knives were used as early as the 28th to 20th centuries BC. In the late Warring States period (third century BC), brass knives were made thanks to the mastery of carburising technology. The drills and saws of that time already bore some resemblance to the modern flat drills and saws.

However, the rapid development of cutting tools came in the late 18th century with the development of machines such as the steam engine. 1783 saw the first milling cutters made by René in France and 1792 saw the production of taps and slabs by Mawdsley in England. The invention of the twist drill was first documented in 1822, but it was not produced as a commercial product until 1864.

In 1868, Mushet in England made an alloyed tool steel containing tungsten. 1898 saw the invention of high speed steel by Taylor and White in the USA. In 1923, Germany's Schluter invented carbide.

In the use of alloy tool steel, the cutting speed of the tool increased to about 8 m / min, when using high-speed steel, and then increased by more than twice, to the use of carbide, and than with high-speed steel increased by more than twice, cutting out the surface quality and dimensional accuracy of the workpiece is also greatly improved.

As the price of high-speed steel and carbide is more expensive, the tool appears welding and mechanical clamping type structure. 1949 ~ 1950 years, the United States began to use in the turning tool indexable inserts, soon to be applied in the milling cutter and other tools. 1938, Germany Degussa company to obtain a patent on ceramic tools. 1972, the United States General Electric Company produced a polycrystalline artificial diamond and polycrystalline cubic boron nitride inserts. These non-metallic tool materials allow tools to cut at higher speeds.

In 1969, Sandvik Steel of Sweden patented the production of titanium carbide coated carbide inserts by chemical vapour deposition and in 1972, Bonza and Laguran of the USA developed a physical vapour deposition method to coat the surface of carbide or HSS tools with titanium carbide or titanium nitride hard layers. The surface coating method combines the high strength and toughness of the base material with the high hardness and wear resistance of the surface layer, resulting in a composite material with better cutting performance.