Keywords : Nickel Aluminide Electroplating
journal of kerbala university,
2008, Volume 4, Issue 3, Pages 129-140
The oxidation behavior of nickel matrix/ aluminum particle composite coatings in air at (600-800°C) for 25 hrs. was studied. The composite coatings were applied to Inconel 600 alloy by the electrodeposition technique and heat treated under argon atmosphere for three hours at 800 °C prior to oxidation testing. During heat treatment, coating morphological development was found to occur by the exothermic reaction Ni +Al = NiAl. For all samples, weight gain kinetics was obtained from furnace exposure and the composition and morphology of the oxidation products were examined using XRD analysis and light optical microscopy. An outer Al2O3 layer was formed on the composite coating surface. At test temperatures such as 800 °C, the coatings benefits from a small grain size that enhances Al diffusion to the surface to form the protective alumina layer.