抄録
The crack initiation mechanism of cast aluminum alloy was addressed to quantitatively evaluate the fatigue strength. The synchrotron radiation microtomography was employed to visualize the three-dimensional damage around pores and Si particles. Two types of specimens were prepared for the low cycle fatigue test. The temperature of solution treatment was different, and it yields a difference in the shape of Si particles. After a certain cycles of fatigue, a catastrophic damage around many Si particles happened and they connected to each other so as to form a crack. The scanning electron microscopy after the test showed that the type of damage was the break of long Si particles or the interface debonding around round Si particles.
