A unified phonon-softening-based model to uncover processing history dependent strain hardening in metallic solids

Recent years, microstructures are taken advantage to promote the improvement of both strength and ductility in metallic solids, or in other words to tailor the strain hardening behavior. Despite complicacy of microstructures, following the same processing protocol, it could guide as-cast samples all the way to the target structure and properties, which suggests that establishing a processing history dependent strain hardening model could be a way out for a better behavior description or even performance prediction. Based on a nonlinear transformation to strain, the common regularity of the processing history influence to metallic solids' strain hardening behavior is uncovered, which helps us to model the processing history dependent strain hardening and its validity is confirmed by comparing with eighteen experimental data sets (66 stress-strain curves). Our theoretical model enables quantitatively describing the processing history dependence of strain hardening and even could be possibly used to characterize processing methods, which may provide insights into the strategy of evading strength-ductility trade-off.