Joining of Presureless Sintered SiC Ceramics using <TEX>$MgO-Al_2O_3-SiO_2$</TEX> System

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J. Korean Ceram. Soc. > Volume 34(7); 1997 > Article

Journal of the Korean Ceramic Society 1997;34(7): 781.

$MgO-Al_2O_3-SiO_2$계를이용한 상압소결 SiC의 접합

이홍림, 남서우, 한봉석, 박병학¹, 한동빈¹

연세대학교 세라믹공학과
¹포항산업과학연구원 구조세라믹스팀

Joining of Presureless Sintered SiC Ceramics using $MgO-Al_2O_3-SiO_2$ System

ABSTRACT

Pressure sintered SiC specimens were joined using MgO-Al2O3-SiO2 (MAS) glass which has a thermal expansion coefficient similar to that of SiC. MAS melt showed excellent behavior of wetting on the SiC substrate over 148$0^{circ}C$, and the wettability was much influenced by the joining atmosphere. The joining was conducted at 150$0^{circ}C$ for 30 min in Ar atmosphere. The flexural strength of the joined specimen shows 342~380 MPa up to 80$0^{circ}C$, which is almost the same as that of as-recieved SiC specimen. However, the flexural strength of the joined specimen decreased to about 80 MPa at 90$0^{circ}C$ due to softening of the glass melt. The analyses od XRD and WDS show that the reaction between the SiC specimen and the MAS melt produces the oxycarbide glass, which had a high strength and a good stability at high temperatures.

Key words: Joining, Flexural strength, Oxycarbide glass, MAS glass