【摘要】 为了改善二硅化钼（MoSi₂）的低温抗氧化性,本文提出了一种原位合成MoSi₂-Si C复合粉末的工艺。首次使用MoS₂、Si和C作为原料制备MoSi₂-Si C复合粉末,相较于Mo、Si和C作为原料可极大降低原料成本。结果表明:当原料中MoS₂∶Si∶C的摩尔比为1∶（4+x）∶x时,在1 400℃反应2 h即可制备MoSi₂-Si C复合粉末,并且可以通过调控x值来调整产物中Si C的比例。制备的Si C颗粒均匀分布在MoSi₂晶粒表面和晶界上,并且随着温度的增加,SiC与MoSi₂一同长大。当温度为1 500℃时,随着产物中SiC比例的增加,MoSi₂的晶粒逐渐减小,这是由于部分生成的Si C分布在MoSi₂晶界处抑制了其长大。更多还原

【Abstract】 In order to improve the low-temperature oxidation resistance of molybdenum disilicide（ MoSi₂）,an in-situ synthesis strategy for the synthesizing of MoSi₂-SiC composite powder was proposed. In this strategy,using MoS₂,Si and C as raw materials for the first time can greatly reduce the cost of raw materials compared to using Mo,Si and C as raw materials. The results have shown that when the sample with the MoS₂: Si: C molar ratio of 1:（ 4 + x） : x and reacted at 1 400 ℃ for 2 hours,MoSi₂-Si C composite powder can be prepared. In addition,the proportion of SiC in the MoSi₂-SiC composite powder can be adjusted by adjusting the value of x. The prepared Si C particles are uniformly distributed on the surface and the boundaries of MoSi₂ grains,and as the temperature increases,SiC and MoSi₂ grains both grow. Moreover,at 1 500 ℃,as the proportion of SiC in the product increases,the crystal grains of MoSi₂ gradually decrease. This is because part of the generated SiC is distributed at the grain boundaries of MoSi₂,inhibiting its growth.更多还原