Characterisation of thermal cycling induced cavitation in particle reinforced metal matrix composites by three-dimensional (3D) X-ray synchrotron tomography

Metal matrix composites are known for their high strength, fatigue resistance, and wear resistance. The coefficient of thermal expansion between the reinforcement and matrix can result in thermal stresses during thermal cycling. In this paper we quantify the evolution of cavitation damage in SiC particle reinforced aluminium alloy matrix composite subjected to thermal cycling by X-ray synchrotron tomography at the advanced photon source at the Argonne National Laboratory. It will be shown that, while surface examination did not show significant damage, X-ray synchrotron tomography enabled us to resolve and quantify the amount and nature of cavitation with increasing thermal cycling. The influence of the microstructure in damage initiation and evolution is discussed.