Abstract
Several studies have been undertaken recently to adapt Yttria Partially Stabilized Zirconia (Y-PSZ) thermal barrier coating (TBC) characteristics during their manufacturing process. Thermal spraying implementing laser irradiation appears as one of these possibilities to modify the coating morphology. This study aims at presenting the results concerning in situ (i.e., simultaneous treatment) and a posteriori (i.e., posttreatment) laser treatments implementing a high power laser diode. In both cases, the coatings were atmospheric plasma sprayed (APS). Laser irradiation was achieved using a 3 kW, average power, laser diode, exhibiting an 848 nm wavelength. Experiments were performed to reach two goals. First, laser post-treatments aimed at building a map of the laser processing parameter effects on the coating microstructure, in order to estimate the laser processing parameters, which seem to be suited to the change into in situ coating remelting. Second, in situ coating remelting aimed at quantifying the involved phenomena. In that case, the coating was treated layer by layer as it was manufactured. The input energy effect was studied by varying the scanning velocity (i.e., between 35 and 60 m.min-1), and consequently the irradiation time (i.e., between 1.8 and 3.1 ms, respectively).
