Abstract
Thermal spray deposits are built layer by layer following several passes of the spray gun in front of the part to be coated. Between each pass, dusts from the surrounding atmosphere and condensed vapors are deposited and hence blur the surface onto which the following layer will be formed; these phenomena weaken the deposit cohesion and lead in the same time to the formation of pores and others stacking defaults. To circumvent such a problem and to improve the deposit overall quality, in situ laser ablation was performed during the coating manufacturing. The ablation stage occurred between each pass. This paper presents at first the experimental device and the major considered processing parameters. Among those, energy density is one of the most critical. It then investigates the structural modifications and the induced improvements obtained for grey alumina coatings considering principally the deposit cohesion and the porosity level.
