莫来石/SiC-Si_3N_4高温结构复相陶瓷的制备  

Preparation of high-temperature structural mullite/SiC-Si_3N_4 multiphase ceramics

作　　者：王克强[1] 卢安贤[1] 罗辉林[1] 罗志伟[1] 孔令娇[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2013年第5期760-767,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51272288)

摘　　要：采用常压烧结工艺制备莫来石/SiC-Si3N4复相陶瓷。采用X射线衍射和环境扫描电镜等对复相陶瓷进行结构分析,测试陶瓷样品的体积密度、开孔率、线收缩率和力学性能。研究结果表明:不同温度下烧结得到的陶瓷主晶相均为莫来石。随烧结温度升高,陶瓷的晶粒长大,内部形成较多闭孔隙,体积密度和线收缩率增大,开孔率减小,显微硬度显著下降,抗弯强度和抗压强度明显提高,其最高分别达到110 MPa和193 MPa。1 600℃烧结的陶瓷样品,随陶瓷中Al2O3和SiO2摩尔比(1:1、11:9、3:2)的增大,体积密度和显微硬度升高,抗压强度增大,气孔变小。The mullite/SiC-Si3N4 multiphase ceramics were fabricated by pressureless sintering. The multiphase ceramics were analyzed by the X-ray diffraction and environmental scanning electron microscopy; meanwhile the bulk density, apparent porosity, linear shrinkage and mechanical properties of the obtained ceramics were also characterized. The results show that the main phase of the obtained ceramics is mullite after sintering at different temperatures. With increasing sintering temperature, the grain size increases, the ceramics form more close porosity, the bulk density and linear shrinkage increase, the apparent porosity decreases, the microhardness decreases significantly, the bending strength and compressive strength are improved obviously with the maximum values of 110 MPa and 193 MPa, respectively. For the ceramic sintered at 1 600 ℃, with the composition of the molar ratio increasing by the order of n（AlzO3）：n（SiO2）= 1：1, 11：9, 3：2, the bulk density, microhardness and compressive strength increase, the pore size decreases.

关 键 词：莫来石 碳化硅 复相陶瓷 显微结构 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]