The constantly increasing economical and ecological concerns in the automotive and aerospace industries have resulted in high demand for improved fuel economy and greater vehicle performance. Lightweight construction is critical for reducing inertial and rolling resistance losses to increase the product performance while maintaining safety and functional requirements. This will open a wide variety of opportunities to implement materials with high strength-to-weight ratios, such as aluminum, magnesium, stainless steel and titanium alloys. However, when using conventional forming processes, these light materials bring about processing challenges: low formability, high yield strength and low strain hardening coefficients. Electrically-Assisted Forming (EAF) is a method of overcoming these limitations. Specifically, EAF is a novel forming process where electricity, AC or DC, is applied to the metallic workpiece through the dies during deformation. Previous experimental investigations have shown that EAF can lead to reductions in flow stress and power consumption, increase in formability through larger achievable strains, the ability to reduce/eliminate springback, and improved precision. This study investigates the influence of electricity on the different lubrication mechanisms by evaluating lubricant performance in an EAF process and identifying potential lubricant candidates for EAF. The tribological conditions have a significant influence on the frictional forces occurring at the die/workpiece interface, thus on the forming load, part quality, and achievable form. When electricity is applied, besides the changes due to surface expansion at the interface occurring in conventional processes, the lubricant is exposed to high localized temperatures and current fields. To analyze this, electrically-assisted ring compression tests are conducted and the performance characteristics of several lubricants are studied. By combining the experiments and finite element simulation results, friction coefficients can be estimated, and the effect of electric current flow on friction characteristics quantified. One goal of this study is to identify possible lubricant candidates to be used in EAF processes.

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