Influence of aging treatment on corrosion behavior and mechanism of Mg–Y alloys

Abstract

This paper studied the influence of aging treatment on the corrosion behavior and mechanism of Mg—Y alloys with different Y content through corrosion mass loss test, electrochemical test and corrosion morphologies observation. Results show that the peak-aging times of Mg–(0.25, 2.5, 5, 8 and 15) Y alloys at 250 °C were 4, 6, 10, 12 and 16 h. The aging treatment reduced the corrosion resistance of Mg–Y alloys, and the corrosion resistance of Mg–Y alloys became worse with increasing of the aging time. The change magnitude of the open circuit potentials for Mg–(0.25, 2.5)Y alloys was greater than that of Mg–(5, 8 and 15)–Y alloys. The polarization curves of Mg (0.25, 2.5, 5, 8 and 15) Y alloys had the similar shape after aging treatment, and the slopes of the anodic branch were greater than those of the cathodic branches. After aging treatment, the corrosion modes of Mg–0.25Y and Mg–(2.5, 5, 8 and 15) Y alloys were uniform corrosion and pitting corrosion with small local deep corrosion.

Keywords

Mg–Y alloy / aging treatment / electrochemical corrosion resistance / corrosion morphology

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