Acta Metallurgica Sinica (English Letters) ›› 2018, Vol. 31 ›› Issue (8): 865-872.DOI: 10.1007/s40195-018-0709-5

Special Issue: 2017-2018镁合金专辑 2018年腐蚀专辑 2018镁合金专辑

• Orginal Article • Previous Articles     Next Articles

Effect of Solution Treatment on Microstructure and Corrosion Properties of Mg-4Gd-1Y-1Zn-0.5Ca-1Zr Alloy

Jian-Wei Dai1,2, Xiao-Bo Zhang1,2(), Yang Fei1,2, Zhang-Zhong Wang1,2, Huai-Ming Sui3   

  1. 1.School of Materials Science and Engineering Nanjing Institute of Technology Nanjing China
    2.Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing China
    3.Yangzhou Fengming Optronic New Material Co., Ltd Yangzhou China
  • Received:2017-11-09 Revised:2017-12-15 Online:2018-08-10 Published:2018-07-27

Abstract:

The as-cast multi-element Mg-4Gd-1Y-1Zn-0.5Ca-1Zr alloy with low rare earth additions was prepared, and the solution treatment was applied at different temperatures. The microstructural evolution of the alloy was characterized by optical microscopy and scanning electron microscopy, and corrosion properties of the alloy in 3.5% NaCl solution were evaluated by immersion and electrochemical tests. The results indicate that the as-cast alloy is composed of the α-Mg matrix, lamellar long-period stacking-ordered (LPSO) structure and eutectic phase. The LPSO structure exists with more volume fraction in the alloy solution-treated at 440 °C, but disappears with the increase in the solution temperature. For all the solution-treated alloys, the precipitated phases are detected. The corrosion rates of the alloys decrease first and then increase slightly with the increase in the solution temperature, and the corrosion resistance of the solution-treated alloys is more than four times as good as that of the as-cast alloy. In addition, the alloy solution-treated at 480 °C for 6 h shows the best corrosion property.

Key words: Magnesium alloy, Solution treatment, Microstructure, Corrosion properties