Effect of humidity on fatigue strength characteristic for magnesium ultrafine wire

In this study, tensile test and fatigue test were carried out under two kinds of environments of low humidity and high humidity using ultrafine magnesium wire with a diameter of 200μm, and the influence of humidity on fatigue characteristics was investigated. As the results, in the low humidity environment and the high humidity environment, clear fatigue limit did not appear, and the fatigue life tended to increase with the decrease of the maximum stress. Fatigue strength at 107 cycles under high humidity environment was reduced by about 48% compared to fatigue strength at 107 cycles under low humidity environment. This is because when the test specimen is exposed to high humidity environment for a long time, the influence of humidity increases.