Mechanical properties and strain-hardening behavior of Mg alloy AZ31B-H24 thin sheet

The strain-hardening behavior of Mg alloy AZ31B-H24 deformed in tension was analyzed using the Kocks-Mecking phenomenological approach. The relationship between strain-hardening behavior and dynamic recrystalliztion at elevated temperatures was investigated in this work. At room temperature, stage II strain-hardening consistent with the forest hardening mechanism, which was similar to that observed in face-centered cubic metals, was observed. The specimens tested at temperatures above 250 degrees C did not show stage II strain-hardening, and their stage III with a decreasing of strain-hardening rate took place immediately after yielding. The absence of stage II strain-hardening should be related to the dynamic recovery and recrystallization, causing the softening effects. The onset of dynamic recovery occurred earlier than that of the dynamic recrystallization (DRX). (C) 2009 Elsevier BY. All rights reserved.