Grain refinement of pure vanadium by equal channel angular pressing

Commercial vanadium of 99.8% purity was extensively grain-refined by application of equal channel angular pressing at 350 °C. A total of eight passes via route BC reduced the grain size from 100 μm to 200 nm. In the as-deformed state, the microstructure consisted mainly of lamellar grains and a smaller fraction of equiaxed grains. A strong fiber texture consisting of <1 1 1>θ and {1 1 0}θ components was also produced by severe plastic deformation. More than a threefold increase of the yield strength was realized by the processing, and a balanced combination of strength and tensile elongation, 406 MPa and 32%, respectively, was obtainable by subsequent recrystallization heat treatment at 700 °C. Dynamic recovery and continuous recrystallization are thought to be the key mechanisms with regard to characterizing the microstructure evolution during deformation and recrystallization, respectively.