(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 以Mo、Si和聚碳硅烷为原料，采用先驱体转化−反应热压制备SiC/MoSi2纳米复合材料，并研究纳米SiC体积分数对材料显微结构和力学性能的影响。结果表明，所制备的纳米复合材料中含有MoSi2、SiC和极少量的Mo5Si3及SiO2。纳米SiC的引入显著地改善了材料的力学性能，15%SiC/MoSi2纳米复合材料的综合力学性能最好，其室温抗弯强度和断裂韧性分别为610 MPa和4.90 MPa/m1/2，比纯MoSi2试样的分别增加了141.1%和58.0%；其高温抗弯强度在1 200和1 300 ℃时分别为720和516 MPa。
关键字: SiC/MoSi2纳米复合材料；先驱体转化；反应热压；力学性能
（State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Using polycarbosilane, Mo and Si powders as raw materials, SiC/MoSi2 nanocomposites were fabricated by precursor conversion and reactive hot pressing. The effects of volume fraction of SiC nanoparticles on the mechanical properties and microstructure of SiC/MoSi2 nanocomposites were studied. The results show that the nanocomposites obtained consist of MoSi2, SiC, less Mo5Si3 and SiO2. The mechanical properties of the nanocomposites are dramatically improved by incorporating of SiC nanoparticles. 15%SiC/MoSi2 nanocomposite has the best comprehensive mechanical properties, with the flexural strength and fracture toughness of 610 MPa and 4.90 MPa/m1/2 at room temperature, which are increased by 141.1% and 58.0% compared with those of MoSi2, respectively. Its flexural strengths at 1 200 and 1 300 ℃ are 720 and 516 MPa, respectively.
Key words: SiC/MoSi2 nanocomposite; precursor conversion; reactive hot pressing; mechanical properties
