高体分SiC_p/Mg复合材料真空气压浸渗工艺及其热膨胀性能  

The properties thermal expansion and process of high volume fractions SiC_P/Mg composites by vacuum-gas pressure infiltration

作　　者：徐志锋[1] 余欢[1] 汪志太[1] 郑玉惠[1] 胡美忠[1] 蔡长春[1] 严青松[1] 

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《功能材料》2007年第10期1610-1613,1617,共5页Journal of Functional Materials

基　　金：江西省自然科学基金资助项目(0650121);航空科学基金资助项目(00H56009)

摘　　要：采用真空气压浸渗法制备了高体分小尺寸SiCp/Mg复合材料,研究了真空压力对小尺寸SiCp多孔体浸渗的影响规律及SiCp/Mg复合材料的热膨胀性能。实验表明,在浸渗温度为983K,压力0.3MPa,保压5min的条件下,其中,能有效浸渗的振实堆积的单一尺寸SiCp多孔体的最小粒径达到了13μm;而32μm的SiCp/Mg复合材料的密度为2.625g/cm^3,SiC颗粒体积分数达到了58.2%。OM、XRD分析表明镁液渗透均匀,无明显的气孔、缩松和熔剂夹杂等铸造缺陷;Mg基体、α型SiC是复合材料的主要组成相,同时还含有少量的MgO、Mg2Si相。此外,32μmSiCp/Mg复合材料在30-200℃温度范围内的平均热膨胀系数为6.5×10^-6/K,表现出了优异的热膨胀性能。High volume fractions SiC9/Mg composites was successful fabricated by vacuum-gas pressure infiltration process. The effects of vacuum pressure and the thermal expansion properties of the SiC9/Mg composites were studied. The results show that the preform of a single minimum SiC particle size 13μm was effectively infiltrated under 0.3MPa pressure, holding time of 5min and temperature of 983K. In the meantime,and SiC particle with size of 32μm and density of 2. 625g/cm^3 and volume fractions of 58.2% are obtained. The analyses results by OM,XRD indicate that SiC particles are uniformly distributed in the Magnesium alloy matrix without casting defects,such as bubble, shrinkage and inclusion. And there are mainly consisted of Mg phase, hexagonal a-SiC phase and with a little MgO phase,Mg2Si phase in the composites. In addition,the coefficient of thermal expansion（CTE） reached 6.5X 10^-6/K in the range temperature of 30-200℃. Obviously,the thermal expansion properties of the SiC9/Mg composites was significantly improved.

关 键 词：真空气压浸渗 高体分 SICP/MG复合材料 热膨胀系数 

分 类 号：TB333[一般工业技术—材料科学与工程]