Abstract
Rotating bending and axial tension-compression (R=-1) fatigue tests were carried out on commercially extruded magnesium alloys (AZ10, AZ31, AZ61 and AZ80). Tensile strength and tensile 0.2% proof stress increased with increasing Al content. Compressive 0.2% proof stress also increased with increasing Al content. Fatigue strength increased with increasing Al content, except for high-strength AZ80 magnesium alloy. The correlation between fatigue strength and compressive 0.2% proof stress was found for extruded magnesium alloys, except for high-strength magnesium alloys. The anisotropic and pseudoelastic deformation behavior in stress-strain hysteresis loops were observed at stress amplitude of fatigue strength for AZ10, AZ31 and AZ61 magnesium alloys. On the other hand, cyclic stress-strain curves of AZ80 magnesium alloy were linear in tensile and compressive phases at stress amplitude of fatigue strength. Lower compressive yielding compared with tension and pseudoelastic deformation behavior due to deformation twins play an important role in fatigue life of low- and intermediate-strength extruded magnesium alloys.
