Acta Metallurgica Sinica (English Letters) ›› 2023, Vol. 36 ›› Issue (8): 1281-1291.DOI: 10.1007/s40195-023-01522-x

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Improved Corrosion Resistance of Ultrafine-Grained Mg-Gd-Zr Alloy Fabricated by Surface Friction Treatment

Chunquan Liu1,2, Xianhua Chen1,2(), Yulong Wu3, Yaobo Hu1,2, Wei Zhang4, Yusheng Zhang4, Jingying Bai5, Fusheng Pan1,2   

  1. 1International Joint Laboratory for Light Alloys (MOE), College of Materials Science and Engineering, Chongqing University, Chongqing, 400045, China
    2National Engineering Research Centre for Magnesium Alloys, Chongqing University, Chongqing, 400045, China
    3Institute of Surface Science, Helmholtz-Zentrum Hereon, Max-Planck Street 1, 21502, Geesthacht, Germany
    4Northwest Institute for Nonferrous Metal Research, Xi’an, 710016, China
    5Beijing Spacecraft, China Academy of Space Technology, Beijing, 100194, China
  • Received:2022-10-12 Revised:2022-12-13 Accepted:2022-12-23 Online:2023-08-10 Published:2023-01-12
  • Contact: Xianhua Chen xhchen@cqu.edu.cn.

Abstract:

Gradient ultrafine-grained (UFG) Mg-2Gd-0.4Zr (wt%) alloy sheet, with a UFG layer of about 118 nm on the topmost treated surface, was fabricated by sliding friction treatment (SFT). The corrosion resistance of the SFT-processed UFG surface layer was greatly improved compared to the original coarse-grained (CG) structure, representing as a higher impedance and a lower corrosion rate (CG: 4.11 mm y−1, UFG: 2.71 mm y−1). The UFG layer with high density of grain boundaries exhibits an excellent impeditive effect on the cracking of corrosion product films. Compared to the CG sample, the stable corrosion product film inhibits the formation of pitting so providing a better protective effect. In addition, the Gd-rich clusters are randomly distributed after SFT processing, which decreases the tendency of galvanic corrosion on the UFG surface.

Key words: Ultrafine grains, Mg-Gd-Zr alloy, Corrosion resistance