Structural study near the film/substrate interface of a plasma sprayed tin coating on low carbon steel

The structure near the film/substrate interface of tin coatings deposited with the plasma spray technique on a low carbon steel substrate is examined with scanning electron microscopy (SEM), X-ray diffraction (XRD), conventional transmission electron microscopy (CTEM) and high resolution electron microscopy (HREM), focusing on the structural properties affecting the corrosion performance. This examination revealed the presence of several Fe-Sn phases, which ensure good adhesion of the coatings to the underlying steel. Furthermore, amorphous Sn or SnOx were also detected in the coating, which, being in low concentration, have no effect on the coating properties.