Enhancing Mechanical Properties of Molybdenum with Equal Channel Angular Extrusion Processing

Molybdenum exhibits many attractive properties, including high thermal conductivity and low coefficient of thermal expansion. Deformation processing helps to increase the strength and hardness of metals; it has also been shown that cold working can improve the room temperature ductility of certain body-centered-cubic refractory metals. In this work, rotary forged molybdenum was processed with equal channel angular extrusion at 400°C to improve the mechanical properties. Four passes of route-A extrusions were used in this study. Microstructure and texture were evaluated by electron backscatter diffraction, while microhardness and miniaturized tensile testing were used to assess mechanical performance. We observed that deformation processing led to a unique microstructural texture and significant improvements in the strength of refractory molybdenum. While the overall of ECAE-processed Mo was comparable to rotary forged materials, it is expected that ductility may be improved if microstructural defects that lead to the localizaion of plastic strains can be suppressed.