Collaborative improvement of strength and ductility over Mo composites enabled by WC and La2O3

Abstract

The low ductility of refractory Mo-based materials limits their further processing and wide applications. To address this challenge, a composite strengthening and toughening strategy was proposed by the simultaneous addition of WC and La2O3. And a collaborative improvement of strength and ductility is achieved over the as-sintered Mo-WC-La2O3, exhibiting a total elongation (TE) of 33.63% and an ultimate tensile strength (UTS) of 611.33 MPa, about 50.27% and 24.76% larger than those of pure Mo, respectively. Furthermore, the corresponding microstructural features and tensile fracture behavior were also discussed to explore the improvement mechanism. And it is found that the enhancement should be attributed to the high relative density, grain refinement, generated substructures and secondary phase particle refinement. Moreover, the additional toughening mechanisms of crack deflection, particles pull-out and crack halt can also prevent crack extension, which helps to give full play to the potential ductility of Mo composites. This work provides a new pathway for manufacturing advanced Mo-based products with excellent strength-ductility balance.