Influence of SiC Content and Heat Treatments on Strength of Al2O3 Ceramics

Abstract

Abstract：In the present study, crack healing effect and residual stress of Al2O3 ceramics were investigated by changing the sintering temperature and heat treatment conditions. And also it was investigated that the influence of different filler loadings of nano-sized SiC particles on the crack healing behavior of Al2O3 ceramics. The test samples were characterized by three point bend flexural tests to evaluate their mechanical properties. The morphological changes were studied by FE-SEM and EDS. The test results indicated that the Al2O3 with nano-sized SiC ceramics sintered at 1800 ℃ were showed highest density. Sintering temperature at 1800 ℃, the bending strength of heat treatment in air atmosphere specimens showed about 42 % increment in comparison to the un-heat treated specimens. The cracked specimens can be healed by heat treatment in vacuum atmosphere but the crack healing effect of Al2O3 ceramics, which is heat treated in air atmosphere was higher than that of heat treated in vacuum atmosphere. Al2O3 with 30 wt% of SiC ceramics indicated higher crack healing ability than that with 15 wt% of SiC ceramics. The FE-SEM images showed that the median cracks and pores were disappeared after heat treatment in air. 김부안(교신저자) : 부경대학교 신소재공학부