Retardation of fatigue crack growth in aircraft aluminium alloys via laser heating – Experimental proof of concept

In this work, a defocused laser was used to modify the residual stress state in AA2198-T8 C(T)100 specimens with the goal of retarding fatigue crack growth. The manuscript provides a description of the process, the resulting changes of the material properties and the modified fatigue crack growth behaviour. The performed experiments, including thermocouple measurements, microscopical examinations, micro hardness measurements, residual stress measurements and fatigue crack growth measurements under constant amplitude loading show, that via laser heating a substantial retardation of fatigue crack growth can be achieved.

► Defocused laser used to induce residual stresses in AA2198-T8 C(T)100 specimens.
► Experimental characterisation of the process and the induced residual stresses.
► Performed fatigue crack growth experiments show substantial retardation effect.