In this paper, effects of the La-rich MM (Misch Metal) on the microstructure, texture and mechanical properties of extruded AZ110 alloy during tension and compression deformation were investigated. High strength and low tension–compression yield asymmetry of AZ110MM alloy (AZ110 alloy with La-rich MM addition) are developed by hot extrusion. The addition of La-rich MM brings Al-RE phases (Al₂(La, Ce) and Al₁₁(La, Ce)₃) to the as-cast AZ110 alloy, which play an important role in the grain refinement and texture weakening during extrusion deformation. Such grain refinement and texture weakening obviously inhibit the nucleation and growth of twins and make the deformation mechanism change from twinning to multiple slip during cold compression deformation. Furthermore, the Al-RE phases also improve the tension–compression yield asymmetry performance of the extruded AZ110 alloy via the combining effects of grain refinement, texture weakening and the transformation from twinning to multiple slip. Moreover, the extruded AZ110MM alloy shows much higher strength over AZ110 alloy, owning to texture effect, grain boundary strengthening and precipitation strengthening.

Graphic Abstract

中文翻译：

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添加富 La 混合稀土改善挤压变形 AZ110 合金的屈服不对称性和提高力学性能

在本文中，研究了富含 La 的 MM（混合金属）在拉伸和压缩变形过程中对挤压 AZ110 合金的显微组织、织构和力学性能的影响。AZ110MM 合金（添加富 La MM 的 AZ110 合金）的高强度和低拉压屈服不对称性是通过热挤压开发的。添加富含 La 的 MM 带来了 Al-RE 相 (Al ₂ (La, Ce) 和 Al ₁₁ (La, Ce) ₃) 到铸态 AZ110 合金，它在挤压变形过程中的晶粒细化和织构弱化中起重要作用。这种晶粒细化和织构弱化明显抑制了孪晶的形核和长大，使冷压缩变形过程中变形机制由孪晶向多重滑移转变。此外，Al-RE 相还通过晶粒细化、织构弱化和从孪晶向多重滑移的转变的综合作用，改善了挤压 AZ110 合金的拉压屈服不对称性能。此外，挤压成型的 AZ110MM 合金由于织构效应、晶界强化和沉淀强化，表现出比 AZ110 合金高得多的强度。

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