Investigation of critical process parameters and design features in fatigue-life of extrusion dies via finite element analysis

Analysis of die failure plays an important role in the prediction and prevention of die failure, and subsequently in improving economics of any metal forming process. The current investigation has shown that finite element simulation and fatigue theory yield an efficient tool for identification of critical process parameters and design features in extrusion die-life in the case of fatigue being the dominating failure mode. For the maximum number of billets extruded by the die before fatigue crack initiation (fatigue life cycles in extrusion), fatigue failure theory based on stress- And strain-life approaches were used for axisymmetric flat die. With the help of finite element software ABAQUS, extrusion process is simulated and dynamic stress and strain values were obtained by first identifying the potential fatigue location in the die. By considering extrusion temperature and strain rate as process parameters and bearing length and fillet radius as die geometric features, different simulation runs were performed to investigate the effect of process and design features on the useful die life. By establishing correlations of die life with process and design parameters under different conditions, it was shown that the present investigation is a useful guideline at die design and extrusion process stages. Keywords: Fatigue analysis, extrusion die, FE simulation, critical parameters.