Cold Spray Nickel-coated Aluminum Composite Powder

NiAl coating can be used as bond coats for thermal barrier coatings (TBCs) with good ductility and excellent resistance against high temperature oxidation. In this study, nickel-coated aluminum composite powders were used to prepare NiAl intermetallic compound coatings on nickel-based superalloys by air plasma spray (APS) high-velocity oxygen-fuel (HVOF) and cold spray (CS) processes. Different spraying parameters in the HVOF and CS processes were used to make different coating microstructures and the coating prepared by APS technique was served as control. The microstructure and phase constitution of the coatings were studied in virtue of XRD, SEM and EDS. The result shows that the deformation behavior of the NiAl powders was different under those spraying parameters. Less defects of oxides and inclusions were observed in the CS coatings comparing with the HVOF coatings.