High-Temperature Oxidation of Nickel-Based Cermet Coatings Containing WC and Al2O3 Nanosized Particles

This paper investigates the high-temperature oxidation of cermet coatings composed of two types of nanosized particles (WC and a mixture of WC and Al2O3) incorporated in nickel and produced by co-electrodeposition. For this purpose, high-temperature oxidation tests were conducted at three temperatures (500, 600, and 700 °C) in dry air with 6 time intervals up to 96 h and mass changes at each specific time interval was measured. Statistical techniques were used to calculate the oxidation rate constants (k) and growth-rate time constants (a) for all coatings. The confidence intervals associated with tests were also calculated. The results showed linear to sub-parabolic oxidation rates for coatings composed of only WC particles and sub-liner to liner oxidation rates for coating with both WC and Al2O3 particles. The reduction in oxidation rates for coatings with both WC and Al2O3 particles were correlated to the addition of Al2O3 particles in the matrix.