Preparation of Self-reinforced Silicon Carbide Ceramics by Hot Pressing

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J. Korean Ceram. Soc. > Volume 36(12); 1999 > Article

Journal of the Korean Ceramic Society 1999;36(12): 1356.

가압소결에 의한 자체강화 탄화규소 세라믹스의 제조

박종곤, 이종국, 서동석, 김민정¹, 이은구, 김환²

조선대학교 재료공학과
¹조선대학교 재료공학
²서울대학교 재료공학부

Preparation of Self-reinforced Silicon Carbide Ceramics by Hot Pressing

ABSTRACT

Self-reinforced silicon carbide was prepared by hot pressing and the control of starting phases of raw materials and its microstructural characteristics was investigated. The specimens with self-reinforced microstructure were obtained from the compacts with mixed compositions of ${alpha}$-and ${beta}$-SiC powders. Self-reinforced microstructure which is composed of large dispersed grains with rod-like shape and matrix with small equiaxed grains was formed by the transformation to the ${alpha}$-SiC with 4H polytype for ${beta}$-SiC and anisotropic grain growth during the heat treatment. Of all speimens the values of volume fraction maximum length and aspect ratio for large grains with rode-like types were the highest at the specimen with 50 vol% ${beta}$-SiC in the starting SiC powder and therefore this specimen showed the highest fracture toughness due to the crack deflection by rod-like grains during crack propagation

Key words: Selfcon, carbide, Self-reinforced microstructure, Hot-pressing