Microstructural characterization of plasma sprayed Al2O3-40Â wt.% TiO2 coatings on high density graphite with different post-treatments

► Plasma sprayed Al2O3-40% TiO2 coatings on graphite with NiAl/Cr3C2-NiCr bond coat. ► Laser melting of sprayed coating reduced surface inhomogeneities and cracks. ► Clusters of Ti-rich particles were observed in annealed coatings. ► Stable phases were formed in annealed and laser melted coatings. ► Average surface roughness order: as-sprayed > annealed coating > laser melted coating.