What is BN coating
Boron nitride is a crystal made up of nitrogen atoms and boron atoms. The chemical composition is 43.6% boron and 56.4% nitrogen, with four different variants: hexagonal boron nitride (HBN), rhomboid boron nitride (RBN), cubic boron nitride (CBN), and fibrozinite boron nitride (WBN). Variants of its cubic crystals are considered the hardest known substances. (It has a Vickers hardness of 108 GPa, while synthetic diamonds have a Vickers hardness of 100 GPa.) ）
Since boron nitride is currently widely used, many people want to ask, is there a substitute for boron nitride? However, as far as the development of industrial technology is concerned, there is no material that can replace boron nitride in a short period of time.
This is very powerful, so what are the characteristics of boron nitride, and what is the use? The following is to introduce the hardness of boron nitride second only to diamond.
Hexagonal boron nitride has good electrical insulation, thermal conductivity, chemical corrosion resistance, and lubrication, and has a strong neutron absorption capacity, almost all organic solvents and corrosive chemicals are relatively stable;
It is chemically inert to almost all molten metals. Below 1000 °C in the air, various physicochemical properties remain basically unchanged;
The temperature used in nitrogen or argon at 3000 °C is still stable.
Hexagonal boron nitride powder is hot pressed and sintered into white blocks, easy to machine, and the temperature resistance can be as high as 2000 °C.
As a chemical material additive, boron nitride is widely used in the fields of military aerospace, ceramics, and cosmetics.
Hexagonal boron nitride and catalyst under high temperature and high pressure to form cubic boron nitride is another new high-tech product after the advent of synthetic diamond.
It has a high hardness, thermal stability, and chemical inertness, as well as good redness and wide band gap width, and other excellent properties, its hardness is second only to gold steel stone, but the thermal stability is much higher than gold steel stone, iron metal elements have greater chemical stability.
According to the characteristics of boron nitride such as high hardness, high melting point, and stable chemical properties, boron nitride coating(BN coating) is widely used in the aluminum smelting industry. For example, the boron nitride rotor used in the degassing box is the most expensive and longest-lasting of the current common rotors. As an antioxidant, boron nitride coatings are widely used in flow tanks, casings, shunt discs, adapter plates, and filter boxes to isolate equipment, parts, and molten aluminum, thus preventing oxidation of aluminum liquid and prolonging the life of equipment and parts.