Demonstration of an endurance limit in cast 319 aluminum
Demonstration of an endurance limit in cast 319 aluminum
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DOI：
10.1007/s11661-003-0206-x
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发表时间：
2003-01-01
影响因子：
2.8
通讯作者：
Allison, JE
中科院分区：
文献类型：
--
作者：
Caton, MJ;Jones, JW;Allison, JE
采用超声波探伤仪对汽车发动机用铸造铝硅铜合金W319-T7的疲劳性能进行了研究。在室温下的应力-寿命（S-N）的行为，确定了该合金的三种凝固条件下，应力的疲劳寿命范围从105到109个周期。将结果与使用伺服液压设备在40 Hz下操作获得的疲劳数据进行比较。没有观察到加载频率的影响。W319-T7的三种固化条件中的每一种都有一个离散的疲劳极限。这一结果的科学和实际意义进行了讨论。通过引入裂纹扩展门槛值条件对先前提出的材料模型进行了修改，以预测所观察到的疲劳极限。该模型可以有效地预测凝固时间对W319-T7疲劳性能的影响。
An investigation of the fatigue properties of cast W319-T7, an Al-Si-Cu alloy used in automotive engine components, was conducted using ultrasonic testing equipment with operating frequencies of 20 kHz. The stress-life (S-N) behavior at room temperature was determined for three solidification conditions of this alloy, where stresses for fatigue lives ranging from 105 to 109 cycles were determined. The results are compared to fatigue data acquired using servohydraulic equipment operating at 40 Hz. No influence of loading frequency has been observed. A discrete endurance limit is indicated for each of the three solidification conditions of W319-T7. The scientific and practical implications of this result are discussed. A material model presented previously is modified by introducing a crack growth threshold condition in order to predict the observed endurance limits. The model is shown to effectively predict the influence of solidification time on the fatigue properties of W319-T7.