Abstract
Thermal spray techniques can fulfill numerous industrial applications. Coatings are hence applied to resist against wear, corrosion, or to modify the surface characteristics of the substrate (e.g., conductivity, etc.). However, many of these applications remain inhibited by some deposit characteristics, such as a limited coating adhesion or pores, or by industrial costs since several non-synchronized steps (i.e., degreasing, sand-blasting and spraying) are needed to manufacture a deposit. The Protal process was designed to reduce the aforementioned difficulties by implementing simultaneously a Q-switched laser and a thermal spray torch. The laser irradiation is aimed to eliminate the contamination films and oxide layers, to generate a surface state enhancing the deposit adhesion and to limit the contamination of the deposited layers by condensed vapors. From Protal arises the possibility to reduce, indeed suppress, the preliminary steps of degreasing and sand-blasting. In addition, in some cases, a significant increase in the deposit adhesion versus standard preparation, a decrease of the porosity level and the increase of the deposit cohesion represent important additional effects of the process.