【作者】 胡侨丹； 李建国；

【Author】 Hu Qiaodan~* Li Jianguo (School of Materials Science and Engineering,Shanghai Jiaotong University,Shanghai 200240,China)

【机构】 上海交通大学材料科学与工程学院；

【摘要】 以 Mo-Si 为反应体系,采用放电等离子烧结技术（SPS）直接合成致密的 MoSi₂块体材料。着重研究了 SPS 合成 MoSi₂的烧结行为和烧结温度对合成材料显微组织及致密性的影响。结果表明:MoSi₂烧结行为分为热膨胀、轻微收缩、剧烈收缩和轻微膨胀四个阶段: 随着烧结温度的升高,合成材料致密性逐渐提高,而 MoSi₂晶粒尺寸逐渐减小;加入过量的 Si 和控制温度,有利于消除 Mo₅Si₃;当烧结温度为1500℃、Mo:Si 为1:2.08时,可获得致密度为99.1%、晶粒尺寸为5～10μm、组织单一的块体 MoSi₂。更多还原

【Abstract】 Using Mo and Si element powders as starting materials,a high-density bulk MoSi₂ was synthesized by spark plasma sintering in one step. Sintering behavior and influence of sintering temperature on microstructures and relative density of MoSi₂ were investigated.The results show that the sintering behavior is characterized by four stages,i.e., initial expansion,slight shrinkage,abrupt shrinkage and slight expansion.The maximum shrinkage displacement increased with increasing sintering temperature.With an increase of the sintering temperature,the relative density of the products was improved and the grain size of the in-situ synthesized MoSi₂ particles is decreased.A slight excess of Si and control of temperature can help to eliminate the second phase（Mo₅Si₃）.Under the conditions of the sintering temperature being 1500℃ and atomic ratio being Mo/2.08Si,dense products of MoSi₂ nearly free of Mo₅Si₃,with the relative density of 99.1% and the average grain size of 5～10 μm,were achieved.更多还原