マグネシウム合金の超高サイクル疲労特性と損傷機構

抄録

In order to investigate fatigue properties of magnesium alloy in very high cycle regime, the cantilever type rotating bending fatigue tests were carried out using AZ31, AZ61 and AZ80 alloys at room temperature in air. As a result of the cantilever type rotating bending fatigue test, S-N curve of AZ61 and AZ80 have the tendency of a duplex S-N curve, and S-N curve of AZ31 has tendency of the monotone decreasing that did not show a clear fatigue limit. The fatigue crack origins in high stress and low cycles area were the twin deformation at the specimen surface, and the fatigue crack origins in low stress and high cycles area were the slip deformation at the specimen surface. As a result of estimating the time strength at 10⁷ cycles using the fatigue limit estimation formula proposed by Murakami et al., the estimated value was close to the experimental value.