High-Temperature Oxidation Resistance and Anti-Oxidation Mechanism of Arc-Sprayed Al,45CT and Composite Coatings

Al coating,45CT coating and Al-45CT composite coating were prepared using arc spraying technology.The morphology,high-temperature oxidation resistance,anti-oxidation mechanism,as well as the microstructure and phase composition of the transition layers of the three kinds of arc-sprayed coatings were analyzed.It was found that the oxide films formed on Al coating and composite coating were peeled off after high-temperature oxidation,and the content of anti-oxidation element Cr was very low.Contrary to the above,arc-sprayed 45CT coating contained a high content of Cr and possessed strong self-repairing ability,while Cr2O3 layer on its surface showed excellent anti-oxidation ability.Moreover,a transition layer was formed at the coating-substrate interface,leading to enhanced adhesion between the coating and substrate and realization of secondary protection by preventing oxidizing gas from entering the substrate.