Boron nitride is a binary phase composed of the same amount nitrogen atom and boron atom. The boron nitride product that Long Yi made is hexagonal boron nitride. The hexagonal boron nitride's property and structure is similar to graphite. Hexagonal boron nitride also called h-BN, and sometimes be called white graphitem, the only ceramic mateirial that can resist 2000℃ high temperature. At present, the boron nitride is widely used on high temperature furnace.