Yield-Point Phenomenon in Impact-Loaded 1060 Aluminum

Abstract

Experiments are described in which flat plates of 1060 aluminum were impact loaded by similar plates at velocities up to 36 m/sec. The resulting elastic and plastic wave shapes were observed after they had traveled 25 mm through the material. It was found that the stress in the so-called elastic wave rose to a peak and then unexpectedly decreased before the following plastic wave again increased the stress toward its maximum value. The relation of the overshoot in stress to dislocation motion is discussed.