摘要
利用非均匀成核的方法在纳米SiC粒子表面包覆一层Al2 O3,通过胶态悬浮液将其均匀分散于Al2 O3 基体中 ,制备出晶内型结构为主的Al2 O3/SiCp 纳米复相陶瓷。通过对材料显微结构及断口形貌分析 ,发现Al2 O3/SiCp 纳米复相陶瓷中 ,含纳米SiC粒子的Al2 O3 晶粒内 ,在残余热应力作用下产生了大量的位错。位错的交截、组合导致微裂纹成核 ,从而诱发材料发生非平面穿晶断裂。
After coating nano_SiC with Al 2O 3 by heterogeneous nucleation processing, nano_SiC particles were uniformly dispersed into Al 2O 3 matrix by mixing them in colloidal suspensions. Consequently, Al 2O 3/SiC p nanocomposites, in which the majority of SiC par _ticles were located in the Al 2O 3 grains, were fabricated. By observation of microstructure of Al 2O 3/SiC p nanocomposites, it is found that the formation of dislocation in the Al 2O 3 grains that contained intragranular SiC was caused by the residual stress. Dislocation crossing and combining lead to form nucleus of microcracks in the Al 2O 3 grains. As a result, non_plane transgranular fracture is induced. The results indicat that the intragranular SiC particles play an important role in changing the fracture mode of the materials.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2001年第5期471-474,共4页
Journal of The Chinese Ceramic Society
基金
清华大学新型陶瓷与精细工艺国家重点实验室资助项目(X .GZ9913)