Conventional and nanosturctured Al2O3–13 wt% TiO2ceramic coatings were deposited by plasma spraying on TiAl alloy surface. Laser remelting experiment on as-sprayed coatings was carried out and the influences of laser remelting on microstructure and thermal barrier effect of the coating were researched. The results show that the as-sprayed conventional coating has a typical plasma-sprayed lamellar-like structure, while the nanostructured coating consisted of both fully melted regions and partially melted regions. The laser-remelted conventional coating exhibits column-like crystals which grew along the direction of the heat current, while the nanostructured coating composed of fine equiaxed grains with some remained nanoparticles. The nanostructured ceramic coating has higher thermal barrier effect than the conventional ceramic coating does. The thermal barrier effect of the as-sprayed coatings decreases after laser remelting.
