Excimer laser surface treatment of plasma sprayed alumina–13% titania coatings

Surface modification of engineering materials allows the production of far superior products in terms of reduced wear, increased corrosion resistance, better biocompatibility, and improved optical and altered electrical/electronic properties. Excimer laser annealing provides a rapid and efficient means for surface alloying and modification of ceramic materials. In this study, alumina–13% titania (AT-13) coatings were sprayed with a water-stabilized plasma spray gun. The coated surface was treated by excimer laser having a wavelength of 248 nm and pulse duration of 24 ns. The surface structure of the treated coating was examined by field emission scanning electron microscope and X-ray diffraction (XRD). A detailed parametric study was performed to investigate the effects of different parameters such as laser energy density (fluence), pulse repetition rate (PRR), and number of pulses on the mechanical properties, surface morphology, and microstructure of the coatings. The study reveals that the laser fluence plays a major role in modifying the surface morphology of the coating, followed by the pulse repetition rate.