Fabrication of a high strength Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy by thermomechanical treatments
Fabrication of a high strength Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy by thermomechanical treatments
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DOI：
10.1016/j.msea.2014.10.077
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发表时间：
2015-01
期刊：
影响因子：
6.4
通讯作者：
Zijian Yu;Yuanding Huang;X. Qiu;Guan Wang;Fanzhi Meng;N. Hort;J. Meng
中科院分区：
文献类型：
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作者：
Zijian Yu;Yuanding Huang;X. Qiu;Guan Wang;Fanzhi Meng;N. Hort;J. Meng
采用热挤压、冷轧和时效工艺制备了高强度Mg-11 Gd-4.5Y-1 Nd-1.5Zn-0.5Zr（wt%）合金。该合金在室温下的平均0.2%屈服应力（YS）为481.6±19.9 MPa，平均极限拉伸强度（UTS）为517.4±27.5 MPa，平均断裂伸长率为2.0±0.4%。在本研究中获得的最佳力学性能具有502.0 MPa的YS，546.8 MPa的UTS和2.6%的断裂伸长率。该合金的高强度是由于晶粒细小、层错（SF）、长周期堆垛有序（LPSO）相以及晶界Mg 5 RE相和晶内β′相的析出。冷轧提高了力学性能，增强了时效硬化响应，但降低了塑性。变形后的合金中同时存在两种织构成分。一种是典型的Mg-RE织构，另一种是罕见的棱柱织构。
A high strength Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy has been successfully fabricated via hot extrusion, cold rolling and ageing treatment. The alloy exhibits an average 0.2% proof stress (YS) of 481.6±19.9 MPa, an average ultimate tensile strength (UTS) of 517.4±27.5 MPa and an average elongation to failure of 2.0±0.4% at room temperature. The best mechanical property obtained in the present study has a YS of 502.0 MPa, an UTS of 546.8 MPa and an elongation to failure of 2.6%. The high strength of this alloy is attributed to the fine grains, stacking faults (SFs), long period stacking ordered (LPSO) phase, and precipitates of Mg5RE phase at grain boundaries and ofβ′ phase inside the grains. Cold rolling improves the mechanical properties and enhances the ageing hardening response, but decreases the ductility. Two texture components are found simultaneously in the deformed alloy. One is the typical Mg–RE texture and another one is the unusual prismatic texture.