High-strain, high-strain-rate deformation behavior of tantalum and tantalum-tungsten based alloys

The microstructural evolution in high-strain, high-strain-rate deformation of annealed tantalum and tantalum-tungsten alloys with 1 and 2.5 wt.% and the occurrence of shear localization has been investigated. The microstructure generated at high strain rates progresses from highly dislocated grains, to lath cells, to subgrains, and finally to small grains as the shear strain increases. The temperature rise predictions from the constitutive equations which describe the materials behavior indicate that the temperature reaches values which allow dynamic recovery, and approach and reach limited localized dynamic recrystallization. This is supported by observations of the microstructure in regions within and adjacent to the shear localization. (orig.)