中文摘要：

采用X射线衍射仪（XRD），扫描电子显微镜（SEM），维氏硬度计，电子万能材料试验机，动态热模拟机研究了稀土／MoSi2复合材料的结构、形貌、硬度、断裂韧性、高温屈服强度、强韧化机理等。结果表明：在MoSi2中添加适量的La2O3，可起到室温强韧化和高温强化作用。随着La2O3含量的增加，样品的硬度、断裂韧性呈先增后减的规律，其最大值分别为10．85GPa，7．25MPa·m^1/2。该材料的强化机制为细晶和优化晶界强化；韧化机制为细晶韧化，裂纹偏转、微桥接和弯曲韧化。

英文摘要：

The structure, morphology, hardness, breaking toughness, high-temperature yield strength, strengthening and toughening mechanism of the RE/MoSi2 composites were investigated by means of X-ray diffraction （XRD）, scanning electron microscope （SEM）, Vichers hardness tester, electrical omnipotence material tester and dynamic heat simulate in this paper. The results showed that the ambient-temperature hardness and breaking toughness, high-temperature yield strength of the samples would increase by adding suitable La2O3 into the MoSi2 material. The hardness and toughness of the specimens would increase, then decrease with increasing the content of La2O3, and their maximum value were 10.85 GPa and 7.25 MPa·m^1/2, respectively, The strengthening mechanisms of composites are the fine grains and optimal crystal boundary strengthening, and the toughening mechanisms are the fine grain toughening and the crack deflection, the micro bridge join and the crack bend toughening.