Abstract
Magnesium rare earth alloys have excellent mechanical properties and good corrosion resistance; as a result, they are used in automobile and aerospace applications. EV31A (Elektron 21) and WE43C (Elektron 43) the two major types of magnesium rare earth alloys that were developed for high performance applications at elevated temperatures. Passivation and stress corrosion cracking behaviors of these magnesium rare earth alloys were investigated in this study. The effect of different heat treatment conditions of EV31A and WE43C on the environmental degradation behavior in alkaline solutions containing different chloride concentrations was investigated. In general, peak-aged condition show better passivation behavior in both alloys. The threshold chloride concentration for passivity break down in 0.1 M NaOH solution was 80 ppm for EV31A, and 200 ppm for WE43C in any heat treatment conditions. EV31A shows higher susceptibility to stress corrosion cracking than WE43C.