Synthesis and Property of La_2O_3-doped MoSi_2

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.