Microstructural evolution and mechanical properties of Mg-11Gd-4.5Y-1Nd-1.5Zn-0.5Zr alloy prepared via pre-ageing and hot extrusion

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:624

Article

Yu, Zijian^1,2,3  Huang, Yuanding²  Mendis, Chamini Lakshi²  Hort, Norbert²  Meng, Jian¹ 

[1] Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Rare Earth Resources Utilizat, Changchun 130022, Peoples R China

[2] Helmholtz Zentrum Geesthacht, MagIC Magnesium Innovat Ctr, D-21502 Geesthacht, Germany

[3] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

关键词: Pre-ageing;    Precipitates;    Deformation;    Recrystallization;    Mechanical properties;   

DOI  :  10.1016/j.msea.2014.11.061

来源: Elsevier

【 摘 要 】

The Mg-11Gd-4.5Y-1Nd-1.5Zn-0.5Zr (wt%) alloy was pre-aged prior to hot extrusion. Pre-ageing treatment introduced uniform distribution of plate-like Mg5RE precipitates, which transformed into nano-scale globular Mg5RE particles by split and spheroidization during hot extrusion. These globular Mg5RE particles contributed to continuous dynamic recrystallization by promoting the evolution of low misorientation sub-grain boundaries to high misorientation grain boundaries and caused grain refinement through grain boundary pinning. The improved mechanical properties were ascribed to the grain refinement, globular Mg5RE and LPSO precipitates. The ratio of compressive to tensile yield strength is 1.2. The yield strength asymmetry was attributed to the deformation asymmetry of LPSO phase and non-isotropic deformation behaviors of Mg matrix in tension and compression. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

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