原位反应热压复合SiCP/MoSi2的显微结构与力学性能

以Mo粉、Si粉和C粉为原料，采用湿法混合和原位反应高温热压一次复合工艺制备了不同配比的SiCp/MoSi2复合材料，研究了该种工艺原位生成的SiC颗粒对MoSi2基体显微结构和室温力学性能的影响。结果表明：原位反应生成的适量SiC颗粒可以细化基体晶粒，改善其力学性能，与同样工艺下制备的纯MoSi2相比，含40vol%SiCp的SiCp/MoSi2复合材料室温抗弯强度是其3.4倍，含50vol%SiCp的SiCp/MoSi2复合材料室温断裂韧性是纯MoSi2的1.5倍；该种工艺的强化机制为细晶强化和弥散强化，韧化机制为细晶韧化。

THE MICROSTRUCTURE AND MECHANICAL PROPERTY OF SiCp/MoSi2 BY IN-SITU REACTION AND HOT PRESS

The molybdenum disilicide matrix composites reinforced with different volume fraction of SiC particles were fabricated by means of in-situ reaction and hot press synthesis after wet mixing the pure powder of Mo, Si and C. The effects of in-situ synthesized SiC particles on the microstructure, fracture surface as well as the room temperature mechanical property of the composites were investigated. The appropriate amount of in-situ synthesized SiC particles could decrease the grain size of MoSi2 matrix and improve its mechanical properties. Compared to the matrix material MoSi2 by the same process, the bending strength of the composite SiCp/MoSi2 with 40 Vol% SiCp was 3.4 times of that of the MoSi2, and the fracture toughness reinforced with 50 Vol % SiCp was 1.5 times. The strengthening mechanism of the in-situ reaction and hot press synthesis technology was the strength dispersion, and the toughening mechanism was the toughening of fine grain. ening of fine grain and dispersion, and the toughening mechanism was the toughening of fine grain.