A new approach to study material bonding in extrusion porthole dies

Porthole die extrusion processes are widely spread even for most recent industrial applications. In turn knowledge base is often linked to make best expertise rather than to scientific fundaments. In the last years several FE models were developed but actual material bonding was not taken into account. In the paper a new approach is presented determining the critical value of the bonding criterion from flat rolling experiments and modelling the actual welding occurring in extrusion of complex profiles. iterion was tested considering an industrial porthole die extrusion process and experimental parts were analysed to validate the proposed approach.