Microstructures of Silicon Carbides Sintered at High- temperatures and Their Significance of Sintering

• Main Authors: Lin, Shih-Min, 林士民
• Other Authors: Yang, Houng-Yi
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/42135353544183578327

碩士 === 國立成功大學 === 地球科學系 === 83 === Silicon carbides sintered at high temperatures including refractory bricks, refractory plates, kiln furniture and heating elements have been collected and analyzed for their microstructures in the present study. On the basis of microstructures, the following four different types of sintered silicon carbides have been recognized: clay-bonded, sialon- bonded, self-bonded and recrystallized silicon carbides. In the clay-bonded silicon carbides, the silicon carbide grains are surrounded by fine-grained cristobalites, mullites of needle form, small amounts of Al2O3- and SiO2-rich amorphous phases, Fe-Si alloy of chondritic form and whiskers of β-silicon carbide. In the sialon-bonded silicon carbides, the silicon carbide grains were surrounded by frame-worked β'-sialon crystals and corundums. In the sintering process, Si3N4 and Al2 O3 were used as sintering agents and were sintered in nitrogen atmosphere. In the self-bonded silicon carbides, the silicon carbide grains were necked among one another and the surface of the grains were coated with thin films of cristbalites. In the recrystallized silicon carbides, in addition to the necking, the silicon carbide crystals have grown well and penetrated each other.