LOW-TEMPERATURE SINTERING OF ALN CERAMICS WITH SHOCK-WAVE TREATED POWDER

AlN powder was shock wave treated under a pressure of 9.8 GPa. X-ray l ine broadening effect was observed in the shocked powder, which is att ributed to the stored strain in the lattice caused by the shock wave t reatment. The strain is appreciable and has a value up to about 3 X 10 (-3) for the (100) plane, which is released during sintering process a nd provides a driving force for densification. Sintered at 1610 degree s C for 4 h, the shocked compact doped with additives has a density of about 98% of the theoretical density, while only 80% for the unshocke d compact. This suggests that the shock waves have an ''active'' impac t on the AlN powder and make it possible for low-temperature sintering .