Corrosion properties of micro-arc oxidation coating on AZ80 extruded magnesium alloy

doi:10.13251/j.issn.0254-6051.2024.01.041

Abstract

Abstract: Aiming at the service environment and surface protection characteristics of magnesium alloy exposed moving parts, micro-arc oxidation (MAO) coating was prepared on AZ80 extruded magnesium alloy. The static corrosion properties of the AZ80 alloy substrate and MAO coating were studied by continuous slat fog corrosion test. Moverover, pre-corrosion of the AZ80 alloy substrate and MAO coating was carried out, and the effect of MAO coating and pre-corrosion time on the corrosion behavior of the AZ80 alloy were analyzed through slow strain rate tensile test. The results show that the MAO coating has good static protection properties. While after salt fog corrosion for 6 days, the pitting corrosion occurs, and then after the coating is damaged the corrosion depends on the corrosion resistance of the AZ80 alloy substrate. Under the slow strain rate tensile condition, the stress corrosion sensitivity increases with the prolongation of the pre-corrosion time, while the stress corrosion sensitivity index of MAO coating is obviously smaller than that of the AZ80 substrate. The MAO coating has obvious protective effect for the AZ80 substrate, which can effectively improve the dynamic corrosion resistance of the magnesium alloy.

Key words: AZ80 extruded magnesium alloy, micro-arc oxidation, salt spray corrosion, stress corrosion

CLC Number:

TG142.2

Tang Jiaqi, Xue Yuna, Wang Cankun, Shen Yi, Liu Xiaolong, Ji Yunzhuo, Fang Ye, Wang Boyao. Corrosion properties of micro-arc oxidation coating on AZ80 extruded magnesium alloy[J]. Heat Treatment of Metals, 2024, 49(1): 256-261.

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