Effect of Si and La additions on the microstructure and mechanical properties of molybdenum wire

The effect and mechanism of the addition of La, Si on the microstructure and mechanical properties of molybdenum wire were explored through the systematic experiments, and the composition of Mo-Si-La alloy wire with excellent mechanical properties was optimized, i.e., Mo-0.15Si-(0.5~0.8)La. Mo₃Si and Mo₅Si₃ particles, which are produced through the in-situ reaction of MoSi₂ and Mo, play excellent effects of grain refinement and dispersion strengthening. La₂O₃ particles make the formation and spread of micro-cracks delayed. In the Mo-Si-La alloy, the presence of molybdenum silicide particles contributes to the more dispersion uniformity of La₂O₃ particles, so the latter's toughening effects are more significant.