OS1204 Fracture Behavior Evaluation of Cast Aluminum Alloy under Low Cycle Fatigue using Synchrotron Radiation CT

Abstract

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.