APPLICATION OF DIFFERENT DEFORMATION MODELS TO EXTRUSION DIES: ELASTO-VISCOPLASTIC WITH KINEMATIC AND ISOTROPIC HARDENING AND MODIFIED TIME-HARDENING CREEP LAW

In the present work, two numerical models were evaluated for the prediction of the level of deformation achieved by an extrusion die during the process after multiple cycles: the Chaboche elasto-viscoplastic model and a modified version of the time-hardening creep law. The latter was developed by the authors in order to include the effect of the temperature and stress levels as well as of the billet length in the computation of the achieved deformation. Both models were then applied to a small scale mandrel used as specimen in a novel physical experiment and tested under different loading, temperature and stress conditions.