Effect of La2O3 on the properties of combustion-synthesized molybdenum disilicide

The phase constituent Of MoSi2 with 2.0 wt.% La2O3 synthesized by self-propagating high-temperature synthesis (SHS) was studied. It was observed 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 morphology of the combustion product was investigated using scanning electron microscopy (SEM). The results showed that the addition of La2O3 could obviously decrease the particle size of the combustion product. Hardness and fracture toughness of the material were directly obtained from the sintered product by using micro-indentation technique. The fracture toughness was found to be significantly enhanced with the addition of La2O3.