CBN is a new type of superhard material with ultra-high pressure and high temperature technology after synthetic diamond using . CBN and its products are mainly suitable for precision grinding of tool steel, alloy steel, heat-resistant steel, stainless steel and other materials. Although the cost is slightly higher than that of general abrasive grinding wheel products, thermal stability and chemical inertness are superior to general abrasive wheels, diamond wheels, etc. Vitrified bond CBN grinding wheels are common used wheels during grinding process.
Grinding performance of grinding wheels is different with diamond, CBN, silicon carbide and corundum abrasive. Diamond is the hardest abrasive, but it’s not ideal used for steel material with large grinding toughness due to poor thermal stability. Silicon carbide wears rapidly due to its low hardness and chemical activity to iron group metals. Corundum is a conventional abrasive used for grinding steel material, but the hardness is relatively low, and the hardness of corundum is not much higher than the hardness of tungsten carbide and vanadium carbide in hardened steel. In addition, the corundum wears relatively rapidly. The physical and chemical properties such as hardness, thermal stability and chemical inertness of CBN are higher than other abrasives, and it is the best abrasives to be used for grinding steel material. Although CBN is more expensive, it is economically justified because of the range of advantages in the grinding process. Through the calculation of a number of economic indicators, the grinding cost of vitrified bond CBN grinding wheels made of CBN compounded with metal powder and ceramic bond at a certain temperature can be saved more than 70% than the grinding cost of corundum grinding wheel.
For grinding materials that are difficult to be processed with high strength, high hardness, high toughness, high viscosity, high temperature resistance and corrosion resistance, the grinding tools should have good physical and chemical properties and mechanical properties. In order to improve grinding efficiency and precision, the grinding wheels should have high toughness and long service like. New type of vitrified bond CBN grinding wheel could perfectly meet these grinding performance requirements. The wide application of the new CBN grinding wheel is incompatible with the physical and chemical properties of the excellent vitrified bond. The performance of the bond interacts with the performance of the CBN abrasive to achieve a similar high crystal strength to produce a phase transition. Tough and brittle microcrystalline pores enable the bond to protect the normal toughness of CBN abrasive grains.