Stress relaxation tests were performed at room and higher temperatures to analyze the determination of the strain rate sensitivity of dislocation stress and the activation volume in Mg-3Al-1Zn alloy sheets. The tensile axis was parallel to the rolling direction.
The activation volume estimated at room temperature decreases with increasing stress at the beginning of the relaxation. The relaxation duration of at least 30 min was used.
At higher temperatures, the activation volume can be determined only from data at the beginning relaxation up to 300 s. Stress relaxation tests at higher temperatures for at least 30 min indicate that recovery processes play an important role in relaxation.