Cailiao Baohu (Jun 2022)

Effects of Laser Surface Alloying on the Microstructure and Corrosion Resistance of AZ91D

  • SHI Xue - mei, LIU Shuai, FAN Qiao - fang, YANG Tie - jun, GUO Feng - ping, CONG Dan, YANG Yi - min

DOI
https://doi.org/10.16577/j.issn.1001-1560.2022.0150
Journal volume & issue
Vol. 55, no. 6
pp. 28 – 33

Abstract

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Owing to the poor corrosion resistance of magnesium alloys, applying proper surface modification treatment to improve their corrosion resistance has become a hot point of current research. In this work, Al powders were pre - placed on the surface of AZ91D magnesium alloy and further treated by laser alloying. The microstructures of the alloyed layer and the substrate were compared and analyzed, and the corrosion resistances of the magnesium alloy and the alloyed layer were tested. Results showed that the gray - white matrix in the laser alloyed area was composed of a small part of α - Mg and a large amount of β - Mg17Al12, the dark black dotted structure was α - Mg+β - Mg17Al12, and the coniferous structure was α - Mg. In all, the laser alloying process refined the α - Mg grains in the alloyed area, reduced the segregation degree of aluminum element, and significantly increased the content of β - Mg17Al12, and therefore greatly improved the corrosion resistance of the magnesium alloy surface.

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