Effect of various additives on sintering of aluminum nitride (Reprinted)

Effects of thirty additives on Sintering AIN were investigated. The additio n of alkali earth oxides and rare earth oxides gave fully densified aluminu m nitride. This is due to the formation of nitrogen-containing aluminate li quid in the system aluminum :nitride-alkali earth oxides or rare earth oxid es. Microstructural studies of the sintered specimens with the above tno ty pes of additives suggested that the densification was due to the liquid pha se sintering. Additions of silicon compounds resulted in poor densification by the formation of highly refractory compounds such as AlN polytypes.