Effect of Electrical Current on Cold Work in Aluminum 2024

Many manufacturers are looking towards electrical treatments as methods for reducing residual stresses in formed metals. Although many people have investigated the effects electricity has on residual stresses and plasticity, there has not been research investigating the effects it has as a post-treatment on strain hardening. Therefore, the goal of this research is to show the permanent changes in tensile properties that electrical treatments have on strain hardened metals, specifically Aluminum 2024. For this initial investigation, only one pulse duration and current density was used to categorize any changes in the metals due to applying electric current. This testing shows the difference between post-deformation heat treatments and post-deformation electrical treatments. Tensile properties of Aluminum 2024 were used to gauge the changes caused by the treatments. The heat treatment had the expected effect of lower the strength of the material and regrowing the grains while the electrical treatment did not seem to drastically change the structure of the grains, but still lowered the strength of the material. Microstructure investigations also showed that the material does in fact show slight changes in material properties, but no drastic changes in microstructure. These images also show that the regrowth from the heat treatment is clearly the reason for the decrease in strength.