Improving deep drawing simulations based on tribological investigations

Blanks of aluminum alloys 5xxx and 6xxx with electric discharge texture (EDT) or milled finish (MF) surface condition are widely used in the automotive industry. The particular tribological conditions during forming of these blanks influence both the product quality and the tool life. Reliable finite element (FE) models which consider the actual contact conditions are required for successful simulation of aluminum sheet forming. Therefore, tribology experiments are useful for creating contact models which represent the actual tribological system between the tool and the blank. In this work, pin-on-plate tribology tests using plates of aluminum alloys 5xxx and 6xxx were performed at different contact pressures, sliding velocities and surface temperatures for investigating the coefficient of friction (COF). The obtained COF as well as the surface topographies of the aluminum blanks were imported into the TriboForm R3 software for generating a multi-factor friction model, which was subsequently applied in deep-drawing simulations using the AutoForm R8 software. The simulation results based on the multi-factor friction model were validated with physical forming trials. The results showed that the multi-factor friction model generally improves the predictive quality of FE simulations.