RESEARCH OF SHOCK_ACTIVATING AND SINTERING OF Si 3N 4 POWDER
Lu Fangyun Cai Qingyu Zhou Xinggui Xue Honglu (Department of Applied Physics, Department of Material Sceince and Chemistry, National University of Defense Technology)
Si 3N 4 powder is activated under two kinds of impulse wave with pressure 15.7 and 25.6 GPa respectively. The activated powder was investigated macroscopically and microscopically. The sintering feature of the activated powder was also studied, and bending strength of the sintered ceramics was measured. The results show that impulse wave has played a positive role in the condensation of the powder during sintering. The bending strength of the ceramics is related to sintering temperature, because, the phase transformation of αβ for Si 3N 4 is a control factor of the strength, and the sintering temperature shows an obvious effect on the transition.