Probing the role of texture in zirconium using dynamic-tensile-extrusion

The effect of high strain-rate and high strains on mechanical behavior has been observed primarily in isotropic, cubic materials. The behavior of low-symmetry, textured, materials is not as well understood. To examine the high strain and high strain-rate response of structural metals, a Dynamic Tensile Extrusion technique has been developed at Los Alamos National Laboratory. In this study, high-purity zirconium bullets were accelerated up to velocities of 615m/s and extruded through a high-strength steel die. The Zr bullets were fired at 23° and 250°C. Specimens were sectioned in two orthogonal directions from the as received plate: (1) loading direction aligned in plane (IP) to the rolling direction and (2) loading direction through thickness (TT) of the plate. A combination of in-situ and ex-situ characterization techniques has been used to study the response of Zr under this dynamic loading condition. Not only are these the first experiments of their kind performed at temperatures higher than room temperature, but high-speed imaging and for the first time, PDV (Photonic Doppler Velocimetry) has been employed to capture the time and velocity of the evolved deformation through the die.