LIU Guoxi 1, LI Kezhi 2, GAO Xiaoju3, ZHANG Cong 4, CHANG Yongwei 5, MENG Quansheng 6, QU Fazeng7
(1. National Key Laboratory of Thermostructure Composites Materials, Northwestern Polytechnical University, Xi’an 710072,
Shaanxi, China; 2. No. 52 Institute of China North Industry Group, Yantai 264003, Shandong, China; 3. Representative
Office of the General Equipment Department Armored in Ji'nan Area, Jinan 250000, Shandong, China)
Abstract: Pressureless sintering has been used to prepare SiC ceramics, and the effect of four kinds of granulated powders on the mechanical properties of sintered SiC body has been studied. Laser particle sizer has been used to detect the particle size, the microstructure of different powders and the sintered body has been observed by SEM. The results show that different granulated powders of SiC obviously affect the mechanical properties of the sintered SiC body. The sintered body obtained from granulated SiC-1 powders is the optimum with the flexural strength of 318 MPa, the hardness of 94.0 HRA and the density of 3.1367 g/cm3. Combined with the microstructure analysis, the sintered body prepared from granulated SiC-1 powders has better properties because of smaller pores and fewer cracks and no free Si and C, as well as the finer size of the granulated powders.
Key words: pressureless sintering; SiC ceramic; mechanical properties; microstructure