Study On Eletroplastic Effect And Electric Impulse Aided Deep Drawing

Uniaxial tensile tests are conducted on AZ31alloy and DP980AHSS with orwithout electric pulses to investigate their mechanical behaviors. The electro-plasticityeffect was isolated by comparing the results under conditions of electric pulses with thoseobtained by isothermal tests under the same temperature. Electric impulses put a greatimpact on the tensile properties of the light weight materials. Comparisons show that withthe electricity, the tensile strength and flow stress of AZ31alloy is reduced, and thedeformation ability is improved as well. However, due to the brittleness of DP980AHSS,the tensile strength first increases (373K-573K) and then decreases (673K-873K)with theincrease of temperature. The ductility of DP980AHSS cannot be improved by employingthe electric impulse. To the contrary, the elongation value hits a bottom at temperature673K. This can be explained by the phenomenon “blue brittleness”. Compared to theresults of with and without current impulse at the same temperature found that pureelectroplastic effect exists in AZ31alloy and not exists in DP980AHSS.In order to modeling the metal flow behavior, the Fields-Backofen flow model wasmodified to incorporate the effect of peak current density and current frequency. It isshown that the calculated results fit well with the experimental ones.For engineering applications, an electric-aided deep drawing set has been designedand established. The effect of electro-plasticity on the deep drawing performance ofAZ31alloy was investigated. The deep drawing depth was increased by employing theelectricity.