Effects of Additives on the Microstructures and Mechanical Properties of <TEX>$Al_2O_3/Al$</TEX> Composites Fabricated from Kaolin

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J. Korean Ceram. Soc. > Volume 36(11); 1999 > Article

Journal of the Korean Ceramic Society 1999;36(11): 1217.

카올린으로부터 제조한 $Al_2O_3/Al$ 복합체의 미세구조와 기계적 성질에 미치는 첨가제의 영향

배원태, 신현택, 하종필

경상대학교 재료공학부

Effects of Additives on the Microstructures and Mechanical Properties of $Al_2O_3/Al$ Composites Fabricated from Kaolin

ABSTRACT

Al2O3/Al composites were fabricated by replacement reaction of molten Al from kaolin instead of quartz glass as preform material. In this case the flexural strength of composites were deteriorated. In order to prevent the decrease in flexural strength by forming the $beta$-type alumina in situ reaction as reinforcement stone powder and clay were added to kaolin as alkali and alkaline earth sources respectively. Composites fabricated from either 2.5wt% stone powder or 5 wt%clay added kaolin preform showed the maximum value of 380MPa as determined by 3-point bending tests. When the content of alkali and alkaline earth in the preform exceed 2.7wt% the flexural strength of the composite decreased in spite of the increased amount of $beta$-type alumina

Key words: $Al_2O_3/Al$ composites, Kaolin, ${\beta}$-type alumina, Alkali and Alkaline earth