In this work, three Mg-9Y-xZn (x = 1, 2, 3, wt%) alloys containing long-period stacking ordered (LPSO) phases were obtained by adjusting the Zn content to investigate the effect of LPSO volume fraction and morphology on the hot workability and hardness of these alloys. The results show that with the increase of Zn content, more lamellar LPSO phases precipitate and prevent the growth of dynamic recrystallized (DRX) grains effectively during hot compression. These lamellar LPSO phases overshadow the promotion effect of interdendritic LPSO phases on DRX, leading to the lower DRX ratio and finer DRX grain size. The hardness values of the compression specimens increase with the increase of Zener-Hollomon parameter and Zn content. And the higher hardness values detected in the WZ93 compression specimens should mainly be attributed to the elevated dislocation density and finer grain size. However, the increasing Zn content leads to the larger activation energy of deformation ( Q ) and narrower suitable parameter zones in the processing maps for the WZ93 alloy. This work clarifies the competing roles of lamellar and interdendritic LPSO phases in DRX and provides new insights for alloy design.
Deng et al. (2026) studied this question.