Damage formation during the deformation of a solidifying Al-Mg Alloy

When load is applied during solidification, damage is accumulated in the form of voids. The evolution of this internal damage was measured via x-ray micro-tomography on interrupted semi-solid tensile test specimens of an Al-Mg alloy, AA5182, in both the as-cast and as-cast and then hot isostatically pressed states. The 3D reconstructed images at each strain level were analyzed to determine the location, size, morphology, and orientation of the damage. Significant internal damage was observed only in the as-cast alloy. By comparing the results from the two materials, it was shown that as-cast porosity plays a large role in the size and distribution of the damage-based voids leading towards hot tearing.