Constitutive modelling for strain–hardening alloys during isothermal compression: An efficient semi-empirical method coupling the effects of strain, temperature and strain-rate

Abstract Constitutive modelling is of importance for metals and alloys which require hot working to improve their mechanical strength. In the present work, a semi-empirical method has been proposed for alloy systems which experience strain hardening e.g. Cu-Cr based alloys, which is easy to implement. This method is based upon the Arrhenius equation, whereby a new parameter α representing the effective stress is introduced. This methodology allows for the effect of strain on the changing back stress to be taken into account, thus the method considers the coupled effects of strain, temperature and strain rate. The value of parameter α can be fitted using exponential function. Experimental data of flow curves during isothermal compression have been used to verify the present model. Compared to the conventional Arrhenius equation using polynomial fitting, the present model reduces the parameters to be fitted without sacrificing accuracy.