상압소결 $\beta$-SiC에 있어서 표면부에서의 액상집중과 미세구조의 변화 = Concentration of Liquid-phase in the Surface Region and Microstructural Change in Pressureless Sintered$\beta$-SiC

다국어 초록 (Multilingual Abstract)

The liquid-phase concentration from the interior to the surface region and its influence on the microstructural changes were investigated in pressureless sintered $\beta$-SiC Surface reaction-layer was formed by reaction of packing powder and volatile components on the surface during sintering which was induced the concentration of liquid-phase in the surface regions. The microstructural changes between the surface region and the interior were appeared in sintered specimen which was resulted from the difference of liquid-phase content during sintering. Microstructural changes were observd with the depth of about 250${\mu}{\textrm}{m}$ from he surface. The grain size and aspect ratio of SiC in the interior are larger than those in the surface region and the rate of transforma-tion of $\beta$-to $\alpha$-SiC during sintering is higher in the interior than that in the surface region.