Laser surface cladding of aluminium with oxide ceramics

The technique of plasma spraying is widely used to produce ceramic coatings of about 1 mm thickness. However, because the as-sprayed coatings are usually porous and are not chemically bonded to the substrate material, their range of application is limited. Recently laser cladding has been applied successfully to produce metallic and hard metal reinforced coatings. In the present work, the suitability of this one-step technique for the generation of ceramic coatings on metal is tested. Especially the Al2O3/TiO2 layers show a compact, non-porous structure and have for the most part good bonding properties. Their adhesive strength is higher than that of plasma sprayed coatings of comparable composition. Finish machining of layers produced by overlapping of single tracks is possible by grinding. Future investigations will be focused on phase analyses and testing of properties as well as on improvement of the material composition.