On temperature and strain-rate dependence of flow serration in HfNbTaTiZr high-entropy alloy

Plastic instability manifested as the serrated flow on stress-strain curves of metal alloys is generally detrimental to their processing and manufacturing. The flow serration in the HfNbTaTiZr alloy is reported in the present work and its dependence on temperatures (573-823K) and strain rates (5 x 10(-5) s(-1)-1 x 10(-3) s(-1)) is investigated with experiments. The notable transition of the onset strain of the serrated flow from a declining (normal behavior) to rising (inverse behavior) trend with increasing temperature at applied strain rates is modeled successfully with a theoretical framework. The success of the model in predicting the onset strain as a function of temperature and strain rate represents a possibility of theoretically constructing a process window for the alloy under examination and beyond. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study investigates the flow serration in the HfNbTaTiZr alloy at different temperatures and strain rates, successfully modeling the transition of the onset strain behavior with a theoretical framework. The model's success in predicting the onset strain as a function of temperature and strain rate represents the possibility of constructing a process window for the alloy theoretically.