A simultaneous improvement of both strength and ductility by Sn addition in as-extruded Mg-6Al-4Zn alloy

• 作者: Xiao-Yuan Wang Yu-Fei Wang Cheng Wang Shun Xu Jian Rong Zhi-Zheng Yang Jin-Guo Wang Hui-Yuan Wang
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2020,（14）
• 页码范围: 117-125
• 页数: 9页
• 语种: 英文

摘要

Commercial wrought Mg alloys normally contain low alloying contents to ensure good formability.In the present work,high-alloyed Mg-6Al-4Zn-xSn (x =1,2 and 3 wt.％,respectively) alloys were fabricated by extrusion.Hereinto,Sn was proven to play an effective contribution to simultaneous improvement in strength and ductility that are traditional trade-off features of synthetic materials.It was found that the average grain size of those alloys decreases significantly from ～11 to ～4 μm as a function of Sn contents increasing from 0 to 3 wt.％,while the amounts of Mg2Sn and Mg17Al12 particles continuously increase.More importantly,the addition of Sn leads to the transformation of dominated deformation modes from {1012} extension twinning (1 wt.％) to pyramidal <c+a> slip (3wt.％) during tensile tests along the extrusion direction at room temperature.The advantageous combination of ultimate tensile strength (～366 MPa) and elongation (～19％) in Mg-6Al-4Zn-3Sn alloy is mainly attributed to the strong strain hardening ability induced by the enhanced activity of non-basal <c+a> slip.This work could provide new opportunities for the development of high-alloyed wrought Mg alloys with promising mechanical properties.