Reaction Sintered Mullite-Spinel-Zirconia Composites

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J. Korean Ceram. Soc. > Volume 32(11); 1995 > Article

Journal of the Korean Ceramic Society 1995;32(11): 1255.

반응소결 물라이트-스프넬-지르코니아 복합체에 관한 연구

박홍채, 편지현, 이윤복, 류수착, 박성수, 오기동

부산대학교 무기재료공학과

Reaction Sintered Mullite-Spinel-Zirconia Composites

ABSTRACT

Mullite-spinel-zirconia composites were prepared by reaction sintering of calcined alumina and magnesia, and zircon powders. The influence of calcining temperature on densification processes and on mechaical properties of subsequently sintered compacts was investigated. The mullite was formed by the reaction of $alpha$-Al2O3 and amorphous SiO2 at firing temperatures over 141$0^{circ}C$. The mullitization proceeded more rapidly in the specimen calcined at 110$0^{circ}C$ than at either 120$0^{circ}C$ or 130$0^{circ}C$. Microstructures before and after the mullitization (or mullite dissociation) showed different morphologies, and their effects on mechanical properties were significant. The flexural strength and fracture toughness of the specimen calcined at 130$0^{circ}C$ and subsequently fired at 145$0^{circ}C$ were 316 MPa and 4.2Mpa.m1/2, respectively.

Key words: Mullite-spinel-zirconia composites, Reaction sintering, Mullitization, Mullite dissociation