SiC whisker reinforced MoSi_2 composite prepared by spark plasma sintering from COSHS-ed powder  

作　　者：许剑光 张厚安 江国健 张宝林 李文兰 

机构地区：[1]Institute of Material Surface Engineering Hunan University of Science and Technology, Xiangtan 411201, China [2]Shanghai Institute of Ceramics,Chinese Academy of Sciences, Shanghai 200050,China [3]Shanghai Institute of Ceramics Chinese Academy of Sciences, Shanghai 200050, China

出　　处：《中国有色金属学会会刊：英文版》2006年第B02期504-507,共4页Transactions of Nonferrous Metals Society of China

基　　金：Project (50232020) supported by the National Natural Science Foundation of China

摘　　要：SiC whisker reinforced MoSi2 composite powder was synthesized by a novel process, referred to the literature as chemical oven self-propagating high temperature synthesis(COSHS). The as-prepared SiCw/MoSi2 composite powder was rapidly sintered by spark plasma sintering(SPS) process. The sintering temperature and pressure were 1 723 K at heating rate of 100 K/min and 40 MPa, respectively. The microstructure and mechanical properties of the composite were investigated. Relative densities of the monolithic material and composite are 95% and 99.3%, respectively. SEM micrographs of SiCw/MoSi2 composite show that SiC whiskers homogeneously distribute in MoSi2 matrix. The composite containing SiC whisker has higher Vicker hardness than monolithic MoSi2. Especially the room-temperature fracture toughness of the composite is higher than that of MoSi2, from 3.6 MPa·m1/2 for MoSi2 to 7.7 MPa·m1/2 for composite with 15% SiC(volume fraction), increased by 113.9%. The morphology of propagation of crack and fractured surface of composite reveal the mechnaism to improve fracture toughness of MoSi2 matrix. The results show that the in-situ SiCw/MoSi2 composite powder prepared by COSHS technique can be successfully sinterded through SPS process and significant improvement of low temperature fracture toughness can be achieved.SiC whisker reinforced MoSi2 composite powder was synthesized by a novel process, referred to the literature as chemical oven self-propagating high temperature synthesis（COSHS）. The as-prepared SiCw/MoSi2 composite powder was rapidly sintered by spark plasma sintering（SPS） process. The sintering temperature and pressure were 1 723 K at heating rate of 100 K/min and 40 MPa, respectively. The microstructure and mechanical properties of the composite were investigated. Relative densities of the monolithic material and composite are 95% and 99.3%, respectively. SEM micrographs of SiCw/MoSi2 composite show that SiC whiskers homogeneously distribute in MoSi2 matrix. The composite containing SiC whisker has higher Vicker hardness than monolithic MoSi2 Especially the room-temperature fracture toughness of the composite is higher than that of MoSi2, from 3.6 MPa·m^1/2 for MoSi2 to 7.7 MPa·m^1/2 for composite with 15% SiC（volume fraction）, increased by 113.9%. The morphology of propagation of crack and fractured surface of composite reveal the mechnaism to improve fracture toughness of MoSi2 matrix. The results show that the in-situ SiCw/MoSi2 composite powder prepared by COSHS technique can be successfully sinterded through SPS process and significant improvement of low temperature fracture toughness can be achieved.

关 键 词：碳化硅晶须 MOSI2 纤维增强复合材料 火花等离子体烧结 COSHS技术 粉末 制备 

分 类 号：TB383.3[一般工业技术—材料科学与工程]