Stress corrosion cracking of a recent rare-earth containing magnesium alloy, EV31A, and a common Al-containing alloy, AZ91E

摘要

Stress corrosion cracking of the magnesium alloy Elektron 21 (ASTM-EV31A) and AZ91E was studied using constant load test in 0.1 M NaCl solution (saturated with Mg(OH)_2), and slow strain rate test using glycerol, distilled water and Mg(OH)_2 saturated, 0.01 M and 0.1 M NaCl solutions. Slow strain rate test indicated that EV31A was less susceptible to stress corrosion cracking than AZ91E. Under less intense loading of constant load, EV31A was found to be resistant to stress corrosion cracking. Fractography of EV31A specimens showed little evidence of hydrogen embrittlement. The superior resistance of EV31A is attributed to a more robust oxide/hydroxide layer.