摘要
采用炸药爆炸驱动飞片加载技术,实现了两种压力(15.7和25.6GPa)的冲击波加载,对氮化硅粉末进行冲击波活化研究.通过运用TEM,SEM,XRD等手段分析了粉末和烧结陶瓷的特性,测试了烧结试件的力学性能.对经过冲击波活化和未经活化的粉末特性比较后得知:在冲击波作用过的粉末中没有发现明显的相变和聚结现象,而粉末颗粒结构中则出现了大量的位错及位错群.对活化粉和未活化粉掺混相同的烧结助剂(5%MgO+5%CeO2)后,在相同的热压烧结工艺条件下进行烧结,结果表明:冲击波活化明显促进烧结的致密化过程,而烧结温度则决定Si3N4的相变过程.因此烧结件的强度将与两者的综合效应相关.
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.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1999年第1期107-111,共5页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金
清华大学新型陶瓷与精细工艺国家重点实验室开放基金