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采用机械化学还原法结合热压烧结制备了Mo_5Si_3-Al_2O_3复合材料,并对复合材料在600℃下的氧化行为进行了研究。结果表明:以MoO_3粉、Mo粉、Si粉和Al粉为原料,机械球磨10h,可获得具有纳米晶结构的Mo_5Si_3-Al_2O_3复合粉体;相比纯Mo5Si3试样,Mo_5Si_3-Al_2O_3复合材料的烧结相对密度和硬度提高,分别达97.2%和1350HV;Al_2O_3的引入可有效防止Mo_5Si_3的低温“粉化”现象,使Mo_5Si_3-Al_2O_3复合材料的抗氧化性明显提高,其氧化动力学曲线呈近似抛物线规律。
Mo_5Si_3-Al_2O_3 composites were prepared by mechanical chemical reduction combined with hot-pressing sintering. The oxidation behavior of the composites at 600 ℃ was investigated. The results show that Mo_5Si_3-Al_2O_3 composite powders with nanocrystalline structure can be obtained by ball milling for 10h with MoO_3 powder, Mo powder, Si powder and Al powder as raw materials. Compared with pure Mo5Si3 sample, the sintering of Mo_5Si_3-Al_2O_3 composite The relative density and the hardness increase respectively, reaching 97.2% and 1350HV, respectively. The introduction of Al 2 O 3 can effectively prevent the low temperature and “powdering” phenomenon of Mo 5 Si 3 and increase the oxidation resistance of Mo 5 Si 3 -Al 2 O 3 composites with an approximate oxidation kinetic curve Parabolic law.