MoSi_2-Ti_3SiC_2复合材料制备及抗氧化性能  

Fabrication and oxidation resistance of MoSi_2-Ti_3SiC_2 composite

作　　者：张俊才[1,2] 贾成厂[1] 史延田 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]黑龙江科技学院材料科学与工程学院,哈尔滨150027 [3]黑龙江省建筑材料工业规划设计研究院,哈尔滨150001

出　　处：《粉末冶金技术》2011年第6期408-412,418,共6页Powder Metallurgy Technology

摘　　要：将Mo-Si-Ti-C机械合金化粉末进行放电等离子烧结(SPS)制备得到MoSi2-Ti3SiC2复合材料。采用X射线衍射分析(XRD)、扫描电镜分析(SEM)等手段对烧结试样进行组织结构分析,并对其进行了300～1 200℃12h的等温氧化试验。研究结果表明,MoSi2-Ti3SiC2复合材料在高温氧化气氛下,具有较好的抗氧化性能。其抗氧化机理为MoSi2和Ti3SiC2发生氧化,产生SiO2,在较低温度下,SiO2没有形成连续保护层,而对材料的保护作用不明显,但当温度达到1 200℃左右时,形成连续保护层,材料抗氧化性能优异。由于第二相Ti3SiC2的存在,即使在较低温度下,如500℃,复合材料的抗氧化性能较纯MoSi2材料也有明显改善。在500℃左右,MoSi2-Ti3SiC2复合材料仍然存在加速氧化(PEST)现象,材料本身致密化程度较低应是产生该现象的主要原因。MoSi2-Ti3SiC2 composite was fabricated with Mo-Si-Ti-C mechanical alloyed powder by spark plasma sintering（SPS）.X-ray diffraction（XRD）,scanning electron microscopy（SEM） were employed to analyse microstructure of materials.The isothermal oxidation experiment of composite material was carried out at five temperatures from 300℃ to 1 200℃.At each temperature the composite was heated for 12h.Results show that： 1） MoSi2-Ti3SiC2 composites have better oxidation resistance at high temperature in oxidizing atmosphere.The oxidation resistant mechanism lies in the production of SiO2 due to oxidation of MoSi2 and Ti3SiC2.At lower temperatures,SiO2 does not form a continuous protection layer which can not protect materials well until the temperature reaching about 1 200℃,then the composite will show excellent anti-oxidation performance.2）As the second phase of Ti3SiC2,even at lower temperatures（such as 500℃）,antioxidation properties of MoSi2-Ti3SiC2 composite is better than that of pure MoSi2 material.3）At about 500℃,MoSi2-Ti3SiC2 composite remains accelerating oxidation i.e.＂ PEST＂ phenomenon.This result may be caused by the lower density of composite.

关 键 词：MOSI2 TI3SIC2 复合材料 抗氧化性 

分 类 号：TQ174.758[化学工程—陶瓷工业]