Hardening and dynamic recovery during hot compression test of copper simulated as viscoplastic material

Abstract

The Norton-Bailey equation was used to simulate by fnite elements the hardening and dynamic recovery of copper during the hot compression tests. The constants of Norton-Bailey equation were determined from the Voce-Kocks model. The simulation assumes a Mortar Contact with Coulomb friction and axial symmetry. Numerical results were compared with experiments. Six compression tests were carried out at 804 K, three with a strain rate of 0.1 s-1 and three with a strain rate of 1 s-1. The results show: The differences between the experiments and the simulations are less than 7.69% for strain rates of 0.1 s-1, and less than 0.67% for strain rates of 1 s-1. This shows that the simulation of hardening and dynamic recovery of hot copper is possible with the Norton-Bailey equation. Better numerical results were obtained when the behavior of copper is typical of hardening and dynamic recovery, and this happen for high values of strain rates.