1 Copyright © 2010 by ASME Proceedings of the 2010 International Manufacturing Science and Engineering Conference MSEC2010 October 12-15, 2010, Erie, Pennsylvania, USA DRAFT-MSEC2010-34249 TRIBOLOGICAL ASPECTS IN ELECTRICALLY-ASSISTED FORMING Cristina Bunget, Wesley A. Salandro and Laine Mears CUICAR – Clemson University Automotive Engineering Greenville, SC, USA KEYWORDS Electroplasticity, Electrically-assisted forming, Lubricants, Tribo-testing ABSTRACT This study investigates the influence of electricity on the different lubrication mechanisms by evaluating lubricant performance in an electrically-assisted forming (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, the lubricant is exposed to high localized temperatures and current fields. 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. INTRODUCTION In recent years automotive legislation has been passed which instills more stringent efficiency and durability requirements for automobiles. To achieve these standards while continually improving fuel efficiency, auto makers are turning to lightweight, non-corrosive construction in the manufacture of their vehicles. Specifically, attention has turned to lightweight alloys with large strength-to-weight ratios and passive, non-corrosive alloys into vehicle construction. For example, 304 stainless steel is used in exhaust components, fuel tanks, chassis and structural components, internal/external trim, and bumpers due to its ability to withstand environmental conditions without corrosion. Implementation into the automobile is limited by the excessive costs and energy required to form this material using conventional manufacturing practices. In fact, many components produced from this material must be produced by assembling several simpler parts using appropriate attachment methods, such as welds, bolts, or rivets. Current Manufacturing Solutions Presently, there are three main manufacturing techniques which a manufacturer may use when forging a lightweight alloy into an automotive component. First, hot working could be utilized, where a material is worked above its recrystallization temperature to achieve reduced deformation forces and increased ductility. However, poor surface finish and dimensional accuracy can result from the excessive heating in this process. The second current manufacturing technique is incremental forming (IF), where a material is deformed in small “increments”, with a process anneal performed in between steps [1]. By doing this, the material can recrystallize, thus allowing for easier plastic deformation and greater achievable part displacements. Unfortunately, this technique is time- and energy-intensive, and part variability can occur since the part must be continuously refixtured after each anneal. The third manufacturing technique is the use of Tailor Welded Blanks (TWB’s), in which different sheets of material (i.e., differences in material grade, thickness, or coating) are welded together before forming in order to place strong, lightweight materials where they are required, while utilizing more formable steels in other areas, thus creating a relatively strong and easily formable part [2]. However, the additional personnel and man- hours needed to fabricate the blanks leads to a relatively expensive and slow process which can potentially vary from part-to-part. Each of these techniques is capable of increasing the formability of lightweight alloys, but at the expense of excessive heat, man- power, production time, and part quality. Each of these factors directly increases the manufacturing cost. Electrically-Assisted Manufacturing A relatively new process, known as Electrically-Assisted Manufacturing (EAM), has proved to be a financially-viable