In the present paper, the influence of locally varying microstructures in case of an AlSi12 cast aluminium alloy is investigated by means of extracting the test pieces from different removal positions and low cycle fatigue tests. The temperature-dependent damage mechanisms, the material specific defect types, sizes and their influence on the fatigue properties of two AlSi7 and AlSi12 cast aluminium alloys are studied. An extreme value statistics methodology is applied to predict maximum defect sizes expected in a critical surface volume from two-dimensional metallographic micrographs. A damage map for the AlSi12 cast aluminium alloy is presented explaining the influence of the temperature- and load-dependent damage mechanisms on the observed isothermal and thermomechanical lifetime behavior.

在本文中，通过从不同去除位置提取试件和低周疲劳试验，研究了 AlSi12 铸造铝合金情况下局部变化的微观结构的影响。研究了温度相关的损伤机制、材料特定缺陷类型、尺寸及其对两种 AlSi7 和 AlSi12 铸造铝合金疲劳性能的影响。应用极值统计方法从二维金相显微照片预测临界表面体积中预期的最大缺陷尺寸。展示了 AlSi12 铸造铝合金的损伤图，解释了与温度和载荷相关的损伤机制对观察到的等温和热机械寿命行为的影响。