The fatigue damage development in a cast Al–Si–Cu alloy

The experimental identification of fatigue damage mechanisms and evaluation of their development rate, based on changes in material respond on cycle loading, has been presented in the work. The research has been conducted on hyper-eutectic cast alloy AlSi8Cu3. The microstructure and fracture analyses were performed. The high cycle fatigue tests were conducted with frequency of 20 Hz under constant nominal stress amplitude with monitoring the strain response of material during the test. The ratcheting was found as the main mechanism of the fatigue damage. It was established that the linear fatigue accumulation law should not be used for fatigue life prediction in case of the tested cast aluminum alloy.