Effect of annealing treatment on the oxidation of an electrodeposited alumina-forming Ni–Al nanocomposite

An electrodeposited alumina-forming Ni–Al nanocomposite having a nanocrystalline Ni matrix dispersing Al nanoparticles was annealed in vacuum at 600 °C, leading to coarsened Ni grains that were doped with a certain amount of Al atoms diffused from the nanoparticles. Oxidation in air at 1000 °C indicated that the annealing decreased the oxidation of the nanocomposite, due to a promotion in the formation of a protective alumina layer. A progressive-oxidation mode demonstrating the competing growth of alumina on the as-deposited and annealed nanocomposites was proposed, as an explanation of the accelerated development of the alumina layer on the annealed nanocomposite.