Enhancing formability of cold-rolled titanium sheets via electro-pulsed treatment: an experimental study on electroplasticity effects

Sheet metal forming processes are widely used across various industries and account for a significant portion of energy consumption in manufacturing. With sustainability becoming a growing focus, researchers are exploring more energy-efficient methods for metal forming. One promising approach is electrical-assisted forming, particularly treatments based on electroplasticity (EP) effects, which can deform metals at lower temperatures and with reduced loads. Among these, pulsed current-based treatments have emerged as a viable alternative to traditional furnace heat treatments, offering significant benefits in terms of process sustainability. This study proposes an innovative pulsed current treatment to reduce the flexural strength of cold-rolled titanium sheets, enhancing their formability and reducing the loads required during sheet metal forming. An extensive experimental campaign was conducted, varying parameters such as current density, number of pulses, grain orientation, and pulse frequency. The effectiveness of the treatment was evaluated by measuring the flexural strength of the specimens, while microstructural analyses were performed to understand the impact of the electric current on the material’s internal structure, particularly in terms of dislocation rearrangement and annihilation. The results demonstrated the effectiveness of the proposed treatment, achieving up to a 19% reduction in flexural strength. This also provided new insights into the complex interaction between electric current and plasticity, an area that remains unclear and is still a subject of ongoing debate.