Microstructure, Deformation, and Property of Wrought Magnesium Alloys
Microstructure, Deformation, and Property of Wrought Magnesium Alloys
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DOI：
10.1007/s11661-020-05974-z
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发表时间：
2020-10-10
影响因子：
2.8
通讯作者：
Zeng, Z. R.
中科院分区：
文献类型：
--
作者：
Nie, J. F.;Shin, K. S.;Zeng, Z. R.
纯镁（Mg）在常规的热轧或挤压加工后形成强的基面织构。因此，它表现出各向异性的机械性能，并且难以在室温下形成。添加适当的合金元素可以弱化甚至改变基体织构，但在成形性和力学性能方面的改善仍远未达到预期。在过去的20年里，人们在变形镁合金的基础和技术层面上做出了相当大的努力并取得了重大进展。在基本层面上，在电子背散射衍射的先进表征技术的帮助下，在不同合金成分的片材和挤压件中形成的以及在不同应变路径或热机械加工条件下产生的织构相对较好地建立。在工艺水平上，板材的室温成形性得到了显著提高，挤压的拉压屈服不对称性也得到了显著的减小或消除。本文首先综述了纯镁单晶中的位错、层错和孪晶以及在不同加载条件下沿着不同取向的变形，然后综述了不同织构、晶粒尺寸和加载条件下多晶纯镁的微观结构（织构和晶粒尺寸）和变形。在此基础上，系统地研究和比较了不同工艺条件下生产的多晶镁合金板材和挤压件的织构、晶粒尺寸和变形。剩余的和新出现的科学和技术问题，然后强调和讨论的纹理和粒度的背景下。更好的分辨率衍射和光谱技术的需要也讨论了织构变化和晶界溶质偏析之间的关系。
Pure magnesium (Mg) develops a strong basal texture after conventional processing of hot rolling or extrusion. Consequently, it exhibits anisotropic mechanical properties and is difficult to form at room temperature. Adding appropriate alloying elements can weaken the basal texture or even change it, but the improvement in formability and mechanical properties is still far from expectations. Over the past 20 years, considerable efforts have been made and significant progress has been made on wrought Mg alloys at the fundamental and technological levels. At the fundamental level, textures formed in sheets and extrusions of different alloy compositions and produced under different strain paths or thermomechanical processing conditions are relatively well established, with the assistance of the advanced characterization technique of electron backscatter diffraction. At the technological level, room temperature formability of sheet has been significantly improved, and tension-compression yield asymmetry of extrusion is also remarkably reduced or eliminated. This paper starts with an overview of dislocations, stacking faults and twins, and deformation of single crystals of pure Mg along different orientations and under different loading conditions, followed by a review of microstructure (texture and grain size) and deformation of polycrystalline pure Mg with different textures, grain sizes, and loading conditions. With this information as a base, texture, grain size, and deformation of polycrystalline Mg alloy sheets and extrusions produced under different processing conditions are systematically examined and compared. Remaining and emerging scientific and technology issues are then highlighted and discussed in the context of texture and grain size. The need for better-resolution diffraction and spectroscopy techniques is also discussed in the relationship between texture change and grain boundary solute segregation.