Tube aluminum nitride

insulatinghigh thermal conductivity

Aluminum nitride is a (mainly) covalently bonded material with a hexagonal crystal structure, which is isomorphic with one of the polytype zinc sulfides called wurtzite. The space group of this structure is P63mc. The material is stable at very high temperatures in an inert atmosphere. In the air, surface oxidation occurs above 700°C, and a surface oxide layer of 5-10nm is detected even at room temperature. This oxide layer protects the material at temperatures up to 1370°C. Above this temperature, bulk oxidation will occur. Aluminum nitride is stable in hydrogen and carbon dioxide atmospheres up to 980°C. The material is slowly dissolved in inorganic acid by grain boundary erosion and dissolved in strong alkali by erosion of aluminum nitride grains. The material is slowly hydrolyzed in water. Aluminum nitride is resistant to most molten salts, including chloride and cryolite. Aluminum nitride is synthesized by carbothermal reduction of alumina or direct nitridation of aluminum. Sintering aids and hot pressing are needed to produce dense industrial grade materials. Application of aluminum nitride The metallization method enables aluminum nitride to be used in electronic applications similar to alumina and beryllium oxide.