Abstract

Magnesium exhibits substantial property enhancement for a vast range of applications via alloying by rare earth elements (REs). The effect of different amounts of alloying elements (Zn and REs such as Gd, Y and Nd) on the microstructure, texture and mechanical properties of Mg has been investigated here by means of optical microscopy, electron backscattered diffraction, shear punch test and hardness test. Results indicate that the recrystallization process along the grain boundaries consists of dynamic, metadynamic and static recrystallization, while dynamic recrystallization as the dominant mechanism gives rise to bimodal microstructures in as-extruded samples with superior properties. The recrystallized area is narrow at low amounts of alloying elements, whereas addition of higher amounts of alloying elements promotes recrystallization, expands recrystallized areas and weakens texture intensity. Moreover, it is observed that there are some optimal REs ratios promoting a partially recrystallized grain structure which in turn provides higher shear strength, hardness values, and more enhanced ductility as well as a weaker texture.

Graphic Abstract

Texture intensity decreases by the increase in the amount of alloying elements

中文翻译：

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新型Mg-Zn-Gd-Y-Nd合金的织构演变和再结晶方面的研究

摘要

镁通过稀土元素（RE）的合金化，在各种应用中均显示出显着的性能增强。通过光学显微镜，电子背散射衍射，剪切冲头试验和硬度试验研究了不同数量的合金元素（Zn和REs，如Gd，Y和Nd）对Mg的组织，织构和力学性能的影响。 。结果表明，沿晶界的再结晶过程包括动态，亚动态和静态再结晶，而动态再结晶作为主要机制，在挤压后的样品中产生了具有优良性能的双峰微观结构。在少量合金元素的情况下，重结晶区域较窄，而添加大量合金元素则可促进重结晶，扩展重结晶区域并减弱纹理强度。此外，可以观察到，存在一些促进部分重结晶晶粒结构的最佳REs比率，进而提供了更高的剪切强度，硬度值和更大的延展性以及较弱的织构。

图形摘要

织构强度随合金元素数量的增加而降低