EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

In recent years aluminum alloy sheets have been increasingly used in the automotive industry for producing lightweight vehicles. However, the complex tribological system and the occurrence of adhesive wear makes forming of aluminum alloys challenging. In particular temperature-induced friction during deep drawing may remarkably alter the tribological system. Therefore, tribological investigations are required at different testing conditions to determine the coefficient of friction (COF) between the aluminum sheets and the forming tools. In this research pin-on-plate tests were performed using pins of steel 1.3505 and plates of aluminum alloys EN AW-6016-T4 and EN AW-5182. The surface of the plates was either electric discharge-textured (EDT) or mill-finished (MF). The tests were performed under both dry and lubricated conditions and at different nominal contact pressures and surface temperatures. The surface topography of the aluminum plates was investigated by means of an optical 3D profiler before and after pin-on-plate testing. The results showed that the COF depends significantly on the testing conditions. For both, EN AW-6016-T4 and EN AW-5182, the COF mostly increased with decreasing contact pressure or with increasing surface temperature. Investigation of the surface topography after pin-on-plate testing revealed remarkable plastic deformation of the surface asperities of the plates. Plastic deformation and wear of the plates increased at higher contact pressures or at elevated temperatures, respectively.