Variability in Dynamic Properties of Tantalum: Spall, Hugoniot Elastic Limit and Attenuation

摘要

A suite of impact experiments was conducted to assess spatial and shot-to-shot variability in dynamic properties of tantalum. Samples had a uniform refined ～ 20 micron grain structure with a strong axisymmetric [111] crystallographic texture. An HEL amplitude of 2.8 GPa (corresponding to Y 1.5 GPa) was observed. Free-surface spall experiments showed clear wave attenuation and spallation phenomena. Here, loading stresses were ～ 12.5 GPa and various ratios of impactor to target thicknesses were used. Spatial and shot-to-shot variability of the spall strength was ±20%, and of the HEL, ±10%. Experiments conducted with smaller diameter flyer plates clearly showed edge effects in the line and point VISAR records, indicating lateral release speeds of roughly 5 km/s.