J. Mater. Sci. Technol. ›› 2020, Vol. 38: 39-46.DOI: 10.1016/j.jmst.2019.06.025

• Research Article • Previous Articles     Next Articles

Age hardening responses of as-extruded Mg-2.5Sn-1.5Ca alloys with a wide range of Al concentration

Qiuyan Huanga, Yang Liua, Aiyue Zhangbc, Haoxin Jiangbc, Hucheng Panbc*(), Xiaohui Fenga, Changlin Yangd, Tianjiao Luoa, Yingju Lia, Yuansheng Yanga**()   

  1. aInstitute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
    bKey Laboratory for Anisotropy and Texture of Materials (MOE), School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, China
    cResearch Center for Metallic Wires, Northeastern University, Shenyang, 110819, China
    dState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, 710072, China
  • Received:2019-03-15 Revised:2019-06-26 Accepted:2019-06-28 Published:2020-02-01 Online:2020-02-10
  • Contact: Pan Hucheng,Yang Yuansheng

Abstract:

This article aims to explore the age hardening responses of both as-extruded and as-aged Mg-2.5Sn-1.5Ca-xAl alloys (x = 2.0, 4.0 and 9.0 wt%, termed TXA322, TXA324 and TXA329, respectively) through microstructural and mechanical characterization. Results indicate that grain size of as-extruded TXA322, TXA324 and TXA329 alloys were ~ 16 μm, ~ 10 μm and ~ 12 μm, respectively. A number of <a> and <c+a> dislocations were observed in all the as-extruded samples. Guinier - Preston (GP) zones were evidently identified in TXA322 alloy, while only a small number of Mg17Al12 phases existed in both TXA324 and TXA329 alloys. An aging treatment facilitated the precipitation of a high number density of GP zones within the matrix of TXA322 alloy. In contrast, no obvious nano-precipitates were in as-aged TXA324 alloy. Numerous nano-Mg17Al12 phases were formed through a following aging treatment in TXA329 alloy. In terms of mechanical properties, it is apparent that an increment in ultimate tensile strength of ~ 46 MPa and ~ 40 MPa was yielded in peak-aged TXA322 and TXA329 alloys, while no obvious variations in UTS were present in peak-aged TXA324 alloy, in comparison with the as-extruded counterparts.

Key words: Magnesium alloys, Age hardening, Precipitations, Dislocations, Mechanical properties