Effect of strain amplitude on tension–compression fatigue behavior of extruded Mg6Al1ZnA magnesium alloy

Fully reversed strain-controlled tension–compression fatigue experiments were conducted on extruded Mg6Al1ZnA (AZ61A) magnesium alloy by employing thin-walled tubular specimens in ambient air. The strain–life fatigue curve displayed a detectable transition from lower cycle fatigue region to higher cycle fatigue region in the vicinity corresponding to a strain amplitude of 0.5%. When the strain amplitude was higher than 0.5%, shear cracking and significant twinning were observed. When the strain amplitude was lower than 0.5%, tensile cracking and little twinning were observed.