3D microstructure and damage accumulation in a cast AlSi12Cu5Ni2 piston alloy as a function of solution Treatment

The microstructural evolution as well as the damage mecha nisms and accumulation during RT tensile deformation of an AlSi12Cu5Ni2 piston alloy for high performance die sel truck engines are studied as a function of solution heat treatment (ST) time at 500°C. For this, interrupted in-situ synchrotron tomography experiments are combined with conventional metallography investigations. The study shows that the lower resistance to structural damage of the alloy after ST is linked to the local disintegration of the highly interconnected 3D network formed by intermetallics and Si embedded in the Al-matrix