Synthesis and properties of <TEX>$Al_2O_3-SiC$</TEX> Composites from Alkoxides III. Effect of Composite Powder Type on the Sintering Characteristics and Properties of <TEX>$Al_2O_3-SiC$</TEX> Comopsites

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J. Korean Ceram. Soc. > Volume 30(4); 1993 > Article

Journal of the Korean Ceramic Society 1993;30(4): 316.

알콕사이드로부터 $Al_2O_3-SiC$ 복합재료의 제조 및 특성 III. 복합분말의 형태에 따른 $Al_2O_3-SiC$ 복합재료의 소결 특성 및 물성

이홍림, 김규영

연세대학교 공과대학 세라믹공학과

Synthesis and properties of $Al_2O_3-SiC$ Composites from Alkoxides III. Effect of Composite Powder Type on the Sintering Characteristics and Properties of $Al_2O_3-SiC$ Comopsites

ABSTRACT

Three types of dispersed, coated and mechanically mixed SiC reinforced Al2O3 composite powders were used to investigate the effect of composite powder type on sintering characteristics and properties of Al2O3-SiC composites. Sinterability of coated type composite powders was superior to that of other composite powders when they were pressureless sintered at 1500~1$700^{circ}C$ for 2h in Ar atmosphere. However, sinterabilities (>98% TD) of each type of composite powders were similar when they were hot pressed at 180$0^{circ}C$ for 1h under 30MPa in N2 atmosphere. SiC powders were randomly distributed in the specimen prepared from dispersed type composite powders, whereas homogeneously distributed for coated type specimens. It was found that SiC powders inhibited the grain growth of Al2O3, and fracture toughness was increased by the increment of crack growth resistance due to residual stress by secondary SiC particles within Al2O3 grains.