Abstract The effect of Zn content and pre-treatment on the microstructure and mechanical properties of Mg-Gd-Y-Zn alloys was investigated. A W-phase was formed, and its volume fraction increased at higher Zn contents between 1 at.% to 2 at.% and broke down from its herringbone shape into particles after extrusion. Both block-shaped 14H-type and lamellar 18R-type long-period stacking ordered (LPSO) strengthening phases were observed in the untreated Z10C alloy, while only the 14H-type was observed in the pre-treated Z10S alloy. W-phase particles and the block-shaped LPSO phase promoted dynamic recrystallization (DRX) behavior due to the PSN effect, which contributed to a weak basal texture. The solution pre-treatment before extrusion led to the formation of a thin lamellar LPSO phase in the grain interior, where the grains were small and fine with a strong texture. The Z10S alloy exhibited the highest strength, as it had the finest grain of all the samples and a strong texture. The differences in deformation of the LPSO phase during compression and tensile stress led to the unusual yield asymmetry compared with that of other Mg alloys.

中文翻译：

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Mg-Gd-Y-Zn合金不同预处理和Zn含量下的显微组织和力学性能

摘要 研究了Zn含量和预处理对Mg-Gd-Y-Zn合金组织和力学性能的影响。形成 W 相，其体积分数在 1 at.% 至 2 at.% 的较高 Zn 含量下增加，并在挤出后从其人字形分解成颗粒。在未处理的 Z10C 合金中观察到块状 14H 型和层状 18R 型长周期堆积有序 (LPSO) 强化相，而在预处理的 Z10S 合金中仅观察到 14H 型。由于 PSN 效应，W 相颗粒和块状 LPSO 相促进了动态再结晶 (DRX) 行为，这导致了弱基底织构。挤压前的固溶预处理导致在晶粒内部形成薄层状 LPSO 相，那里的颗粒小而细，质地结实。Z10S 合金表现出最高的强度，因为它具有所有样品中最细的晶粒和坚固的质地。与其他镁合金相比，LPSO 相在压缩和拉伸应力期间变形的差异导致了异常的屈服不对称。