マグネシウム合金押出材の回転曲げ疲労限度と機械的性質の相関

抄録

In order to investigate the correlation between fatigue limit and static strength of extruded Mg-Al-Zn alloys, rotating bending fatigue tests with three types of Mg-Al-Zn alloy, AZ31, AZ61 and AZ80, were carried out. And static tensile test and compression test with these alloys were also performed. On the other hand, in order to clarify the correlation between them, more than 200 past literature researches on fatigue property of various Mg alloys were surveyed. As a result of past literature research, it was found that there was a proportional relationship between fatigue limit and static strength. The fatigue limit and the static strength obtained by the experiment of this study agree well with the proportional relation obtained as a result of the literature survey. In particular, considering the super long life fatigue range up to 10⁸ cycles or more, the fatigue limit of AZ31 and AZ61 was found to be almost equal to their compressive 0.2% proof stress. However, it was found that the fatigue limit of AZ80 is lower than the compressive 0.2% proof stress. The best method to predict the fatigue limit of all materials was through the use of tensile strength.