Characterization of bonding quality of a cold-sprayed deposit by laser resonant ultrasound spectroscopy

Resonant ultrasound spectroscopy was utilized to determine the mechanical properties of a planar interface between a cold-sprayed iron deposit and an aluminum alloy substrate. The measurements were done at room temperature and with a thermal cycle from room temperature to 500 °C. The properties of the interface were assessed by analyzing the resonant frequencies of a sandwich-like sample by means of a numerical model. While the as-sprayed deposit at the room temperature exhibited a perfect adhesion to the substrate, the thermal cycle led to deterioration of the properties due to precipitation of FeAl₃ along the interface and subsequent cracking. The modal analysis enabled localization of the damage zone along the interfaces and simulating its temperature evolution during the cooling run.