In this paper, the authors evaluate the effect of different laser parameters on the adhesion of coatings produced by the Protal method. The process incorporates an atmospheric thermal spray torch and a pulsed Nd:YAG laser, achieving surface preparation (comparable to grit blasting) and coating deposition in a single step. Coating adhesion was measured via tensile testing and an indentation method, and the rupture areas (along with some of the coating-substrate interfaces) were examined using SEM techniques. The results show that with the new process chemical and metallurgical bonding can be achieved between the substrate and coating by spraying in air.

Surface preparation prior to thermal spraying is a key step in ensuring a good adhesion of the coating onto the part to be coated. This article discusses the effects of laser treatment conditions on the substrate topography and coating adhesion. It investigates the properties of various types of coating applied to aluminum and titanium substrates using the PROTAL process. The paper compares the results obtained from coating of substrates directly in the "machined" state with those of a classical process (degreasing and subsequent sandblasting using aluminum oxide before coating). The results show that the PROTAL process offers the potential to avoid degreasing and steel shot blasting in numerous coating systems even with critical material combinations. In addition, the economic aspects of the process are discussed. Paper includes a German-language abstract.

A composite was obtained by spraying ferromagnetic powder with a plasma arc torch onto an aluminum substrate. The influences of spraying conditions (substrate temperature, plasma gas composition, powder granulometry) on the efficiency of the induction heating by the composite are investigated.

In this work, the benefits of the Protal process were investigated, comparing adhesion and morphology of different APS thermal spray copper coatings onto an aluminum base substrate. The Protal process operates simultaneously an atmospheric thermal spray torch and a Q-switched laser (Nd:YAG) to perform surface preparation and coating deposition in a single operation. In that case, substrates are coated rough from the machine shop, i.e. without any prior surface preparation. Results obtained in this way were compared with results obtained using a classical procedure, Le, degreasing followed by sandblasting prior to coating deposition.