EFFECT OF UPSETTING-EXTRUSION-UPSETTING ON THE RECRYSTALLIZATION OF AN Mg-9Gd-4Y-2Zn-0.5Zr ALLOY

In this study, the effect of upsetting-extrusion-upsetting (UEU) on the microstructure of an Mg-9Gd-4Y-2Zn-0.5Zr alloy and on dynamic recrystallization (DRX) was investigated. The results showed that after UEU, DRX occurred in the Mg-9Gd-4Y-2Zn-0.5Zr alloy. Namely, the grain refinement at the cross-sectional edges of UEU specimens was significant, with the grain size being refined from 8.27 ??m in the necking region to 6.57 ??m. Grain refinement is mainly caused by DRX where the long-period stacking order (LPSO) phase stimulates DRX around the grain boundaries through a particle-stimulated nucle-ation mechanism. DRX grains play an important role in weakening the texture by offsetting the severely deformed structure of deformed grains.

Automated summary

This study investigates the effect of upsetting-extrusion-upsetting (UEU) on the microstructure of an Mg-9Gd-4Y-2Zn-0.5Zr alloy and dynamic recrystallization (DRX). It was found that DRX occurred in the alloy after UEU, leading to significant grain refinement at the cross-sectional edges. The grain refinement was mainly caused by DRX stimulated by the long-period stacking order (LPSO) phase through a particle-stimulated nucleation mechanism.