Development and Characterization of MgO Coatings on 316L Stainless Steel

The present work deals with the development of MgO coatings on ASTM 316L stainless steel using pulsed laser deposition technique employing KrF excimer laser ( λ = 248 nm). Two important process variables, namely oxygen partial pressure and substrate temperature, were varied to get uniform coatings. The process parameters were optimized based on the microstructure and uniformity of the coatings, which had the direct bearing on the performance of the coating. Structural, morphological and microstructural characterizations of the coatings were carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy. While XRD studies confirmed the phase purity and the strain associated with the coating and the substrate, SEM studies revealed the microstructural integrity and morphology of the coatings in addition to establishing the chemistry of coatings. Field testing of the coatings for their sodium compatibility, particularly in aggressive conditions of incineration, confirmed the successful performance of the coatings.