Influence of yttrium-induced twinning on the recrystallization behavior of magnesium alloys

The present study was designed to investigate the role of {11 (2) over bar1} extension twinning on deformation and subsequent recrystallization behavior of binary Mg-Y alloys (Mg-5wt.%Y and Mg-10wt.%Y). The selected alloys in solutiontreated condition were uniaxially deformed at room temperature and then annealed. Increasing the Y content switches the dominant twinning mode from {10 (1) over bar2} extension twins and {10 (1) over bar1} {10 (1) over bar2} double twins, to less commonly observed {11 (2) over tilde1} extension twins. The former was found to assist recrystallization, while the contribution of latter in the formation of new grains was minimal. Moreover, the concurrent precipitation in the Mg-10Y alloy pins the grain boundaries and twin boundaries and thereby suppresses the recrystallization of the alloy despite holding for a longer duration. Finally, the weakening of the annealing texture was only observed in the Mg-5Y alloy as compared to the Mg-10Y alloy. This was attributed to the grain boundary bulging as the prominent mechanism of recrystallization in the Mg-10Y alloy.

Automated summary

Increasing Y content changes the dominant twinning mode and affects the recrystallization behavior of Mg-Y alloys. Precipitates in Mg-10Y alloy pin grain boundaries and twin boundaries, suppressing recrystallization. Grain boundary bulging is identified as the main mechanism of recrystallization in Mg-10Y alloy.