抄録
Magnesium alloys that are used in safety related parts and other applications are subjected to repetitive or fluctuating dynamic stresses under service conditions. Therefore, it is important to understand the fundamental fatigue properties of such alloys under corrosive environments. In this study, the fatigue behavior of extruded AZ80-T5 magnesium alloy has been evaluated under corrosive environments: (a) high humidity environment (80%RH) and (b) 5wt.%NaCl environment. Fatigue tests were conducted under axial loading at stress ratio -1 and at a frequency of 20Hz for a lifetime as long as 10^7 cycles. It was found that, under the corrosive environments, especially under the NaCl environment, the fatigue strength of AZ80-T5 reduced drastically. Fracture surface examination on the scanning electron microscope indicated that pit formation induced the reduction of fatigue life of AZ80-T5 magnesium alloys under the corrosive environments.
