Reactive oxide-dispersed Ni3Al intermetallic coatings by sediment co-deposition

Ni-Al-reactive oxide (REO) ternary composite coatings were successfully deposited from a Watt's nickel bath containing Al particles and REO particles via the sediment co-deposition (SCD) technique. Three different composite systems, Ni-Al-nano CeO2, Ni-Al-5 μm CeO2, and Ni-Al-Y2O3 (<1 μm), were studied. The volume fraction of the Al particles in the composite coatings was significantly decreased with an increase of the REO bath loading, while the REO particle content positively increased. The REO particles in the plating bath evidently interfered with the deposition of Al particles. The development of intermetallic phases in the annealed Ni-Al-REO composite coatings mainly depended on the Al content in the coatings. REO-dispersed Ni3Al intermetallic coatings could be formed as long as the REO particle loading in the bath was controlled below a critical level. Transformation of CeO2 phase to CeAlO3 was found in the Ni-Al-nano CeO2 composite coatings during the annealing treatment at 800 °C.