抄録
To study of the low-cycle fatigue behavior of an extruded magnesium alloy, total strain controlled low-cycle fatigue test was performed using smooth round bar specimens of AZ80. In the experiment, two types of specimens, such as, extruded (F) and T5-aging treated (T5), were prepared to discuss the effect of microstructure of the material on fatigue behavior. Low-cycle fatigue life of the F-specimen was longer than that of the T5-specimen, in spite that the static strength was large in the T5-specimen compared with the F-specimen. Distinctive shape of a hysteresis loop was observed on the both kinds of specimens, that is, asymmetric shape between tensile side and compressive side was existed. It was suggested from the experimental measurement of elastic recovery strain occurred during the loading-unloading test that the asymmetric shape of the hysteresis loop was caused by the twin deformation which occurs easily during compressive loading. This unique behavior was affected by the microstructure of material and tended to disappear by the aging treatment.
