High speed laser cladded Ti-Cu-NiCoCrAlTaY burn resistant coating and its oxidation behavior

To improve the high temperature oxidation resistance and burn resistance performance of titanium alloy, Ti-Cu-NiCoCrAlTaY composite coating was designed and deposited on TC4 alloy using a novel high speed laser cladding technology. The chemical composition, constituent phases, microstructure and morphology of the coating were characterized by EDS, XRD, SEM and 3D laser microscope respectively. The oxidation behavior of laser-cladded Ti-Cu-NiCoCrAlTaY coating and TC4 titanium alloy was analyzed at 800 °C. It was found that the functional coating has good oxidation performance attributed to the formation of dense double layered composite oxide scales. The flame-retardant functions of TC4 substrate and Ti-Cu-NiCoCrAlTaY coating were evaluated through laser spot melting test. The high thermal conductivity of copper and high anti-oxidation of NiCoCrAlTaY promote the flame retardant performance. The formation of TiCu eutectic transition zone in front of the substrate also helps to delay the combustion process.