Fabrication and wear characteristics of MoSi2 matrix composite reinforced by WSi2 and La2O3

Abstract MoSi 2 matrix composites (RWM) reinforced by the addition of both WSi 2 and La 2 O 3 were fabricated by mechanical alloying and self-propagating high-temperature synthesis (SHS) technique. This composite was analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is difficult to synthesize RWM composite by mechanical alloying with Mo–W–Si–La 2 O 3 powder mixture, and suitable by self-propagating high-temperature synthesis. The hardness and toughness of MoSi 2 was improved significantly by the addition of both, WSi 2 and La 2 O 3 more than by only WSi 2 . By adding 0.8 wt.% La 2 O 3 and 50 mol.% WSi 2 into the MoSi 2 matrix, this composite has the highest hardness and toughness and exhibits more wear resistance than monolithic MoSi 2 during the sliding wear test under oil lubrication, in this case, the material removal mechanism has been observed to be micro-cutting and micro-fracture.