La_2O_3掺杂MoSi_2的SHS合成及其性能研究

Synthesis and Property of La_2O_3-doped MoSi_2

以Mo粉、Si粉和La2O3为原料,通过自蔓延高温燃烧合成(SHS)的方法制备了La2O3掺杂的MoSi2材料.研究表明,掺杂剂La2O3的加入对MoSi2燃烧合成过程的热力学和动力学具有明显的影响.并通过XRD和SEM对燃烧合成产物的物相组成和形貌进行了分析,发现La2O3的加入对合成产物的物相组成没有明显影响,但可以大大降低合成产物的晶粒尺寸.同时,力学性能研究结果表明,La2O3的加入可以提高MoSi2材料的室温断裂韧性.

La2O3-doped MOSi2 was synthesized by self-propagating high-temperature synthesis. The morphology of the combustion product was investigated by using scanning electron microscopy. The fracture toughness at room temperature was measured by Anstis' mode and the responded microstructure was analyzed by using SEM. The results show that the addition of La2O3 as a doping agent significantly influences the thermodynamics and kinetics of combustion process when compared with the combustion synthesis of molybdenum disilicide alone. The addition of La2O3 can obviously decrease the particle size of the combustion product, and the addition of La2O3 can obviously toughen the matrix.