摘要
采用少量Si_3N_4作为添加剂,研究了热压Al_2O_3/TiC复合陶瓷的显微组织特征。透射电镜观察表明α-Al_2O_3、β′-sialon、TiC三者之间具有不同特征的结合面;玻璃相主要存在于晶界和晶粒交界的“三态点”处,长柱状的β′-sialon在该处形核并长大;α→β′相变是一个溶解-沉淀过程。同时材料在高温热压时的变形过程中,主滑移和次滑移系位错之间以及位错与TiC粒子之间相互作用形成不同的位错组态,高温快冷时次滑移系位错被保留下来,低温慢冷时回复使主滑移系位错大部分消失。
The microstructure of Al_2O_3/TiC ceramics with additive of Si_3N_4 was investigated by means of TEM. The results show that the interfaces between α-Al_2O_3, β'sialon and TiC are different, the glass phase exists obviously at the grain boundary or the 'triple point' of grains. The β'-sialon particles are prismatic in shape, nucleating at the 'triple point' of grains and growing along the grain boundary. Thesolution-pre-cipitation process during α→β' phase transformation is described. Upon the deformation of a-Al_2O_3 during hot-pressing at high temperature, the different dislocation structures could be formed by the interaction of dislocations on the basal and non-basal slip systems with each other or TiC particles, most of the dislocations can be presented during quick cooling at high temperature, but the basal system dislocations then mostly disappeared upon slow cooling at low temperature.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1991年第6期537-542,共6页
Journal of The Chinese Ceramic Society
关键词
复合陶瓷
显微组织
界面
相变
位错
ceramics
interface
phase transformation
dislocation
