Abstract
The morphology of sprayed splat raises the coatings adhesion and the properties which are determined by the spraying parameters. A lot of studies in this field show that the substrate surface temperature is a very relevant factor for the splat shape: the hypotheses of substrate surface wetability and contamination or absorption layer on the surfaces are supported by the fact that the near disk-shaped splat can be obtained in increasing the substrate temperature. In the PROTAL process, a short duration pulse laser is used to ablate the substrate just before powder spraying. This ablation is powerful enough to eliminate the contaminations on the substrate surface and to improve the adhesion. In this study the analyses of NiAl splat morphology on polished TA6V substrate were carried out using PROTAL process with different substrate temperatures and different heating modes: the flame and another laser. Results show that the temperature at which the disk shaped splat can be obtained was decreased dramatically by PROTAL process and PROTAL process combined with another laser has increased the adhesion strength of the coatings.
