Processing and properties of Mg–6Gd–1Zn–0.6Zr: Part 1 – Recrystallisation and texture development

A Mg–6Gd–1Zn–0.6Zr alloy has been hot rolled, and the recrystallisation and texture development examined. During recrystallisation it was observed that the recrystallisation caused dissolution of the γ′ particles that had developed during hot rolling. These coherent particles provided significant Zener pinning, and resulted in relatively slow recrystallisation kinetics. The texture of the recrystallised grains after hot rolling was weak, and this weak texture persisted into the fully recrystallised condition. It is concluded that the weak textures that develop in this alloy are due to the dominance of oriented nucleation of recrystallised grains at the prior grain boundaries during hot rolling and subsequent annealing.

Research highlights▶ The recrystallisation texture after hot rolling was found to be remarkably weak for a magnesium-based alloy. ▶ The weak recrystallisation texture has been found to result from oriented nucleation of recrystallised grains. ▶ The presence of the γ′ phase in the hot rolled state significantly hindered recrystallisation. ▶ Recrystallisation resulted in the dissolution of the γ′ plates.