Investigation by 3D nano-holotomography of the self-healability of an Aluminium alloy produced by additive manufacturing

Al parts might be subjected to overloads leading to voids, cracks and the replacement of the part. A promising solution is to use self-healing material. A self-healing Al alloy was produced by SLM based on Al-Si and Mg powder. The microstructure is composed of a Si network and Mg2Si precipitates in a α-Al matrix. During an overload, void nucleation occurs due to fracture of the Si network and of precipitates. The idea is to use a heat treatment to trigger the diffusion of the healing agents to the cavities. The healing potential of fractured Mg2Si was already proven but the SLM microstructure is different and its influence on the healing efficiency and kinetics needs to be investigated. Nanoholotomography allows observing the same area before and after healing in order to track the damage and to assess the healing potential of the material. As the SLM microstructure will not be noticeable, FIB-SEM will be used to evidence the influence of the microstructure on the healing efficiency.