高纯度MoSi2粉末的合成与分析

采用机械合金化法、高能机械化学法、化学法+高能球磨法等3种方法实验合成MoSi2粉末,并对其成分和物相进行了分析。实验结果表明,化学法+高能球磨法可高效地合成出高纯度MoSi2粉末,其工艺为:按照Mo∶Si∶C=1∶3∶7(原子比)配制MoO3粉末、SiC粉末和碳粉的混合粉末,在1 200℃下,在刚玉管炉中,用50%Ar-50%H2混合气体对其还原12 h,获得MoSi2-SiO2混合粉末,用氢氟酸溶液除去SiO2粉末,获得纯MoSi2粉末,然后高能球磨4 h以改变其颗粒形貌和粒度组成。

SYNTHESIS AND ANALYSIS OF HIGH-PURITY MoSi2 POWDER

By the three methods including mechanical alloying,high-energy mechanochemistry,chemical synthesis ＋ high-energy ball milling,MoSi2 powder was experimentally synthesized.And its chemical composition and phases were analyzed.The experimental results show that by the method of chemical synthesis ＋ high energy ball milling,high-purity MoSi2 powder can be efficiently synthesized.The processing is that firstly at 1 200 ℃,mixed powder of MoO3,SiC and carbon with Mo∶Si∶C=1∶3∶7（atomic ratio） is reduced for 12 h in the corundum tube furnace,using mixed gas of 50% Ar-50% H2 as reductant.The reaction product is MoSi2-SiO2 powder mixture,which is immersed in hydrofluoric acid solution to remove SiO2 powder.Then pure MoSi2 powder is milled for 4 h by high-energy balls to change its morphology and particle size distribution.