Effect of microstructure evolution on mechanical property of extruded Mg–12Gd–2Er–1Zn–0.6Zr alloys
Effect of microstructure evolution on mechanical property of extruded Mg–12Gd–2Er–1Zn–0.6Zr alloys
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DOI：
10.1016/j.jma.2014.12.003
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发表时间：
2015-03
影响因子：
17.6
通讯作者：
Kai Wen;Ke Liu;Zhaohui Wang;Shu-bo Li;W. Du
中科院分区：
文献类型：
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作者：
Kai Wen;Ke Liu;Zhaohui Wang;Shu-bo Li;W. Du
用光学显微镜、X射线衍射仪、扫描电子显微镜和透射电子显微镜研究了铸态、挤压态和峰时效态Mg-12Gd-2Er-1Zn-0.6Zr合金的组织演变。本文还通过室温拉伸试验测试了复合材料的力学性能。结果表明，在793℃、24 h的固溶过程中形成了层状14H-LPSO结构，热挤压后仍存在片层结构。热挤压过程中发生动态再结晶。经深冲X射线衍射后的细晶尺寸为∼5~μm，同时，一些含有LPSO结构的未经深冲X射线衍射的晶粒沿挤压方向有大致的取向。拉伸试验结果表明，挤压态合金具有较好的延伸率为14%，这是由于合金具有细小的DRXed晶粒和具有较高延伸率的LPSO组织的纤维状非DRXe。由于β‘相的析出，合金的极限拉伸强度和屈服拉伸强度分别提高到415 Mpa和374 Mpa。
The microstructure evolution of as-cast, as-extruded and peak-aged Mg–12Gd–2Er–1Zn–0.6Zr alloys were investigated by Optical Microscope (OM), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The mechanical performance was also tested by tensile test at room temperature in the present study. The results indicated that the lamellar 14H-LPSO structure formed during the solid solution process at 793 K for 24 h, and also existed after hot extrusion process. The dynamic recrystallization (DRX) occurred during hot extrusion. The DRXed fine grain size was ∼5 μm. Meanwhile, some un-DRXed grains contained LPSO structure had a roughly orientation along the extrusion direction. The tensile test result showed that the as-extruded alloy had a better elongation of 14% due to fine DRXed grain and fiber-like un-DRXed with LPSO structure attributed to the high elongation. Because of the precipitation of theβ′-phase, the ultimate tensile strength (UTS) and yield tensile strength (YTS) increased up to 415 MPa (UTS) and 374 MPa (YTS), respectively.