Ductilizing Mo alloys via nanoparticle-stabilized microstructural hierarchy

Swaged Mo-xLa(2)O(3) alloys (x = 0, 0.3, and 0.6 wt.%) were subjected to different annealing temperatures (T-a ), in order to demonstrate the T-a -sensitive La2O3 effect on microstructural evolution and tensile ductility. Although coarse La2O3 particles were detrimental to ductility, nanosized La2O3 particles were found to increase the ductility by highly stabilizing the deformation-induced hierarchical microstructures of lamellar elongated grains with low-angle grain boundaries inside. A competition between the two opposite effects derived from the La2O3 addition led to an unexpected x-dependence of ductility upon different T-a . IMPACT STATEMENT Hierarchical microstructure of laminated grains with numbers of LAGBs, as stabilized by nanoparticles, significantly ductilized Mo alloys, which opens an access to improve the ductility of refractory metals.