Effect of Precipitated Phases on Corrosion of Mg95.8Gd3Zn1Zr0.2 Alloy with Long-Period Stacking Ordered Structure

摘要

The microstructure of the precipitated phases of Mg_(95.8)Gd_3Zn_1Zr_(0.2) alloys with long-period stacking ordered structure before and after heat treatment is discussed.The corrosion properties of the as-cast(F),solid-solution(T4) and aging-treated(T6) alloys in 1%NaCl solution are studied.The hydrogen evolution and electrochemical measurements display that the as-cast Mg_(95.8)Gd_3Zn_1Zr_(0.2) alloy with the continuous network eutectic phase exhibits the greatest corrosion resistance,while T6 sample with some needle-like phases and the particle phases is the worst among the three alloys.It is proposed to be mainly related to the amount,composition,microstructure and distribution of the precipitated phases.