Impact of Strain Rate on Plastic Properties of Metals

The choice of technological factors and the clarification of the impact of strain rate at the impulse-high-speed processing of metals has a high degree of significance. Generally, there is no single opinion on the character of changes in the parameters of plasticity with the increase of the strain rate. When testing carbon and alloy steels, aluminum, copper and its alloys, a decrease in plasticity was observed at high strain rate, which is explained by the existence of a "critical speed" for the mentioned materials at which the destruction occurs instantaneously. A metal that is essentially loaded with an impulse load shows that plastic deformation occurs by twinning and sliding within the grain. During this load, elastic-plastic waves occur in the workpiece, where the magnitude of the stress is related to the speed of propagation of the wave.