Direct nitridation of aluminum compacts at low temperature

Direct nitridation of aluminum compacts (relative density 65%) consisting o f commercial atomized powder was examined at temperatures from 500 to 700 d egrees C, near or below the melting point of aluminum, and under a pressure d nitrogen atmosphere between 0.5-7 MPa. Complete nitridation was achieved at a temperature as low as 540 degrees C by controlling the nitrogen pressu re. The nitridation process and the structures of generated aluminum nitrid e (AIN) were drastically influenced by nitrogen pressure. Considering the r elations between the reaction conditions and the reaction processes, it is suggested that low nitridation temperature and pre-heating in vacuum have a good effect on the nitridation ratio. (C) 2000 Kluwer Academic Publishers.