Dynamic compressive behavior of selected aluminum alloy at low temperature

This paper deals with the effect of low temperature on the compressive behavior at high strain rate of two aluminum alloys, 2024-T4 and 7075-T6 using a modified split Hopkinson pressure bar (SHPB) with a pulse shaper technique. A cooling device is specially designed to be coupled to the SHPB, which can reach temperatures as low as 123 K. Using experimentally determined stress–strain curves, the effect of low temperature on the dynamic compressive behavior is determined and discussed, showing that flow stress increases with the decrease of temperature, and the strain hardening behavior is almost independent of temperature ranging from 123 to 300 K. A simplified constitutive model based on the consideration of thermally activated dislocation motion is proposed. The prediction provided by the model gets satisfactory agreement with the experiments.