对AZ31B镁合金板材在室温下的高周疲劳性能进行了研究, 用红外成像仪测量了疲劳试验过程中合金表面的温度变化; 根据疲劳试验过程中温度-应力关系及试样表面温度分布差异, 确定疲劳断裂位置和疲劳极限。结果表明: 根据合金表面温度变化可以预测疲劳断裂位置; 以此法确定的AZ31B镁合金的疲劳极限为107.5 MPa, 与常规疲劳试验测得的疲劳极限吻合较好; 加载初期镁合金升温到一定温度后又下降至室温左右, 在断裂前温度快速升高。

High-cycle fatigue property of AZ31B magnesium alloy plats at room temperature were studied, and the temperature changes on the surface of samples was tested by infrared thermographic technology. The fatigue fracture position and fatigue limit of the alloy was confirmed according to the relationship between temperature and stress during fatigue test and the temperature distribution difference on sample surface. The results show that the fatigue fracture position could be predicted according to the change of the temperature on alloy surface, and the fatigue limit tested by the method was 107.5 MPa, the value was agreement with the fatigue limit tested by conventional fatigue test. The temperature of magnesium alloy increased to a certain temperature, and then decreased to room temperature at the earlier stage of loading, and the temperature raised quickly before fracture.