Assessment of Fatigue Behaviour of Aluminium Foams by Synchrotron X-ray Microtomography

摘要

Compression-compression fatigue behaviour has been measured for closed cell aluminium foams by the synchrotron X-ray microtomography. The microstructures such as micropores, particles, and cracks in foams were 3D visualized. The local tomography technique is applied, which enables a high-resolution CT-imaging for a region of interests within a sample larger than a field of view of the high-resolution imaging setup. Under compressive cycles, fatigue behaviour through such microstructures has been observed using an in-situ test rig. It was found that micro-cracks were mainly initiated from coarse micropores and cell walls were also damaged. The fatigue crack propagation in a cell wall was tracked increasing the cycle number comparing with the microstructures from 3D images and the relations between the microstructures and the fatigue behaviour are discussed.