Microstructural and tensile characterization of Inconel 718 laser coatings for aeronautic components

The suitability of the laser cladding technique for manufacturing and repairing aeronautic components of Inconel 718 was evaluated. Multilayer coatings were deposited on Inconel 718 plates, using a continuous wave Nd:YAG laser. The microstructure of the laser cladding samples was investigated using optical and scanning electron microscopy and microhardness profiles were measured after different heat treatment stages. Finally, tensile tests were carried out on fully aged samples extracted from a massive multilayer coating. It was proven that the resulting coatings satisfy the industrial requirements for aeronautic applications, with mechanical properties well above the minimum specified values and with no detrimental phases or precipitates left after the heat treatment.

► As-clad coating presents columnar dendritic structure with a Ni-γ matrix and different interdendritic precipitates.
► Solubilization eliminates undesired Laves phase and causes precipitation of small needle-like δ particles.
► Aging improves hardness by precipitation of γ′ and γ″ phases.
► Aged laser cladded coatings properties surpass the industrial requirements for aeronautic applications.