Investigation and numerical modelling of extrusion tool life time

The extrusion process is used to produce aluminium and copper profiles. The tools are typically made of hot-work tool steels and subject to high cyclic thermal and mechanical loadings. Due to the local appearing high temperatures which can reach up to 580 °C within the die for aluminium extrusion additionally creep-fatigue damage occurs. The final goal of the current activities is the numerical description of the entire extrusion process regarding mechanical and thermal loads during a real life pressing cycle and the coupled fatigue and creep damage. Process data are provided by an extrusion company, whilst the steel vendor makes all necessary material data available. The simulation of the heat treatment and the resulting state of a die used is the basis for the subsequent modelling of the cyclic loads during the press cycles. The material behaviour is described by a visco-plastic model and damage is predicted using an incremental life time rule. The resulting life time is comparable to typical ones in the extrusion industry. Also the location of maximum damage agree well with observed cracks in withdrawn dies.