Abstract
Although it is widely used prior to the spraying stage to eliminate the surface contaminants and to improve the splat contact with substrate, a preheating operation should be precisely controlled to keep the metallic substrate away from an excessive oxidation. In most cases, the oxide scale can deteriorate the interface adhesion. A nanosecond pulsed laser treatment is a powerful tool to remove the surface oxide layers. It is also the fundamental principle of the PROTAL process that combines a laser surface preparation and the thermal spraying process. In this paper, a nanosecond pulsed laser was used to remove the thermally induced oxide while keeping the advantage of preheating. It is shown that the particle splashing was suppressed and the deposit adhesion was significantly improved resulting from the laser cleaning effects. The mechanism of oxide removal is also investigated.
