Cubic Boron Nitride (CBN) is an extremely hard abrasive that is used to grind materials such as ferrous metals, ceramics and some super alloys. It has a Mohs scale hardness rating of 10, second only to diamond on the scale. It has excellent abrasion resistance and superior chemical stability versus carbon. CBN is able to work at much higher temperatures than pure diamond and can be used for grinding high-speed steels without degradation.

It is very stable under elevated temperatures and can be annealed at 1,600 to 2,400°C (3,700 to 4,800°F) without losing its hardness. Its thermal conductivity is among the highest of all metals and a high-density crystalline structure makes it an effective electrical insulator. It is a very important component of abrasive technology and can be used in a variety of applications.

CBN can be made in a variety of ways, including consolidated with high pressure and temperature techniques and by spark plasma sintering. It can also be formed in a nanostructure using the Hall-Petch effect with a grain size of 14 nm, which increases its mechanical properties. The most commonly utilized form of cbn is a polycrystalline abrasive that can be densified in hot isostatic pressing or spark plasma sintering with silica as the sintering aid.

CBN is available for a wide range of products and can be produced to customer specifications. Several deposition methods have been developed to improve film thickness, crystallinity, residual stress and adhesion. Ion-assisted physical vapor deposition and chemical vapor deposition have been successfully employed to deposit cBN coatings on various substrates.