摘要
采用一次粒径分别为 10nm和 15nm的α Al2 O3 和SiC粉体为原料 ,制备了Al2 O3 /SiC纳米陶瓷复合材料·纳米SiC颗粒明显抑制Al2 O3 基体晶粒的长大 ,SiC体积分数超过 4 %时 ,材料的断裂方式由沿晶断裂变为穿晶断裂·随SiC含量的增加 ,Al2 O3 /SiC纳米复合材料的硬度增大·材料的弯曲强度和断裂韧性在SiC体积分数为 5 %时达到最大值·最大三点弯曲强度和断裂韧性分别为 6 4 1MPa和 4 7MPam1/2 ,明显高于热压单相Al2 O3 陶瓷 (344MPa和 3 1MPam1/2 )
Al 2O 3/SiC ceramic nanocomposites were fabricated from nanocrystalline α Al 2O 3 (10?nm in diameter) and SiC (15?nm in diameter) powders. Nanocrystalline SiC particles restrain remarkably the grain growth of the Al 2O 3 matrix. When SiC content exceeds 4%, fracture mode of the composites is changed from intergranular to transgranular. Hardness of the Al 2O 3/SiC composites increases with increasing SiC content. Both three point bending strength and fracture toughness reach the maximum values at a SiC content of 5%. The maximum three point bending strength and fracture toughness are 641?MPa and 4 7?MPa m 1/2 , respectively, higher than those of the hot pressed Al 2O 3 ceramic (344?MPa and 3 1?MPa m 1/2 ). Strengthening mechanisms are interpreted mainly due to the intragranular particle residual stress and the grain refining.
出处
《东北大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2002年第5期451-454,共4页
Journal of Northeastern University(Natural Science)
基金
教育部跨世纪优秀人才培养计划基金资助项目 (2 0 0 110 10 0 2 )
辽宁省自然科学基金资助项目 (9910 3 0 0 10 2 ) .
