Modeling of double action extrusion—A novel extrusion process for friction characterization at the billet–die bearing interface

The friction in the bearing channel of hot aluminium extrusion was studied by using a novel simulative friction test: double action extrusion (DAE). FEM simulations of DAEs were carried out to evaluate two commonly used friction models. It was found that full-sticking friction represents the experimental results the best. For a further understanding of the DAE, a theoretical model was developed, and a good agreement between the modeling results and experiments was obtained. The theoretical modeling results revealed that the length difference of the extrudates was caused by the combined effects of friction and material rate dependence at elevated temperatures.