Abstract
Inconel 718 and Maraging Steel (18Ni300) were deposited via direct metal laser deposition (DMLD) on to high strength stainless steel (SS418) as a possible solution for a fuel nozzle swirler wear application. For the same opportunity, a Cobalt based alloy, L605, was deposited using the high-pressure Cold Spray (CS) system. Detailed characterization of the two additive manufacturing processes (DMLD and Cold spray) was carried out, for porosity, microstructure, phase stability, and structural integrity (bond strength, tensile strength and wear), to assess the suitability of the two different Additive Manufacturing (AM) techniques for addressing the swirler wear problem via new manufacturing technologies. Interfacial chemistry, dilution, heat affected zone and distortion were characterized for the DMLD deposition, while interfacial bonding and wear behaviour were studied for the cold sprayed coating. The fretting wear behavior of both AM processes and materials, was studied, to ascertain the suitability of the cold sprayed coating for wear applications. Detailed characterization and comparison of both the manufacturing technologies led to the DMLD process and maraging steel to be chosen as suitable for repair and restoration of the fuel nozzle swirler in the gas turbine.
