HIGH-STRAIN, HIGH-STRAIN-RATE DEFORMATION-BEHAVIOR OF TANTALUM AND TANTALUM-TUNGSTEN BASED ALLOYS

The microstructural evolution in high-strain, high-strain-rate deforma tion of annealed tantalum and tantalum-tungsten alloys with 1 and 2.5 wt.% and the occurrence of shear localization has been investigated. T he microstructure generated at high strain rates progresses from highl y dislocated grains, to lath cells, to subgrains, and finally to small grains as the shear strain increases. The temperature rise prediction s from the constitutive equations which describe the materials behavio r indicate that the temperature reaches values which allow dynamic rec overy, and approach and reach limited localized dynamic recrystallizat ion. This is supported by observations of the microstructure in region s within and adjacent to the shear localization.