Boron Nitride is the crystal which is compose of nitrogen atoms and boron atoms. The structure of this crystal can be categorized as HBN, WBN and CBN; the crystal structure of HBN is quite similar to graphite. HBN also is known as ‘white graphite’ because its appearance is loosely, smoothly, easy-to-moisture white poder. The density of this product is 2.27g/cm³,; its specific gravity is 2.43; its Mohs hardness scale is 2. HBN has excellent electric insulation, thermal conductivity, chemical stability; and it does not have obvious melting point. HBN will sublimate at 3000℃ in 0.1/MPA nitrogen; its melting point is 3000℃ in inert gas; its heat-resistance can reach at 2000℃ in restored neutral atmosphere; its using temperature also can reach at 2800℃ in nitrogen and argon; its stability is relatively poor in oxygen and the using temperature is below at 1000℃. The coefficient of expansion of HBN is equivalent to quartz however its thermal conductivity is ten times as that of quartz.
HBN can not be dissolved in cold water, but it can be hydrolyzed in boiling water and produces a little bit of boric acid and ammonia. This product does not react with weak acide, alkali at room temperature; it will slightly dissolve in hot acid. Decomposition of HBN needs to use melting sodium hydroxide and potassium hydroxide.