The origin of exceptionally large ductility in molybdenum alloys dispersed with irregular-shaped La2O3 nano-particles

YJ Chen and Y Fang and PM Cheng and XX Ke and MC Zhang and JW Zou and J Ding and BZ Zhang and L Gu and QH Zhang and G Liu and Q Yu, NATURE COMMUNICATIONS, 15, 4105 (2024).

DOI: 10.1038/s41467-024-48439-2

Molybdenum and its alloys are known for their superior strength among body-centered cubic materials. However, their widespread application is hindered by a significant decrease in ductility at lower temperatures. In this study, we demonstrate the achievement of exceptional ductility in a Mo alloy containing rare-earth La2O3 nanoparticles through rotary- swaging, a rarity in Mo-based materials. Our analysis reveals that the large ductility originates from substantial variations in the electronic density of states, a characteristic intrinsic to rare-earth elements. This characteristic can accelerate the generation of oxygen vacancies, facilitating the amorphization of the oxide-matrix interface. This process promotes vacancy absorption and modification of dislocation configurations. Furthermore, by inducing irregular shapes in the La2O3 nanoparticles through rotary-swaging, incoming dislocations interact with them, creating multiple dislocation sources near the interface. These dislocation sources act as potent initiators at even reduced temperatures, fostering diverse dislocation types and intricate networks, ultimately enhancing dislocation plasticity.

Return to Publications page