INFLUENCE OF DYNAMIC PROPERTIES ON PERTURBATION GROWTH IN TANTALUM

The perturbation method is employed in an experimental-numerical study of the behavior of Ta subjected to both shock and shockless (approximately quasi-isentropic) loading. The loading produces large deformation plastic flow, pressures on the order of 10-80 GPa, and strain rates on the order of 10{sup 5}-10{sup 9} s{sup -1}. Metallographic analysis is used to assess microstructural changes. Perturbation growth is reasonably well predicted with the use of a finite element continuum code and the Steinberg-Glushak model. Perturbation growth in Ta is compared to that of Al and Cu. Observations are made concerning fundamental differences in the behavior of fcc versus bcc materials subjected to the studied load environment. Ramifications of these differences on model development is discussed.