Assessment of solutions to reduce wear with the warm forming of aluminum

Abstract

Aluminum warm forming can be used to form very hard sheet materials and reduce the weight of the parts produced, helping to lighten cars. While many studies have focused on the aluminum warm forming technique, few examine the effects of temperature on sheet - tool contact conditions during repetitive parts making. The purpose of this study is to focus on the different sheet/tool contact configurations with the warm forming of aluminum based on 2 types of tests: tribological testing for an initial range of contact configurations and press testing of the forming tool for the final evaluation of a range of configurations. 18 configurations, involving various materials, tool coatings and lubricants, were initially evaluated using a warm pin test on an AW5083 H111 sheet. According to the analysis of wear surfaces, adhesion/galling type damage occurred on pins and highlights the importance of lubricating with a beneficial influence of tool coatings. The analysis of the coefficient of friction alone cannot explain the degraded aspect of the pins obtained. Then press tests with a tunnel-shaped part were carried out on 4 selected configurations. If the coated and lubricated configurations are satisfactory, the uncoated and lubricated configurations are surprisingly good and better than the tribological results have shown. In addition to the risks of pick-up and galling, the deposits of residues on the tool are compared for the lubricants tested.