Structure of Al-based composite coatings prepared by thermal diffusion of the arc-ion plating Al coatings

Abstract

In order to improve the high-temperature oxidation resistance of the hydrogen-resistant steel, Al coatings were firstly deposited on the hydrogen-resistant steel by arc-ion plating and then the thermal diffusion treatment was used to produce the Al-based composite coatings on the hydrogen-resistant steel. The effect of thermal diffusion parameters on the structure of Al-based composite coatings was studied. The crystal structure, composition and morphology of Al-based composite coatings were analyzed by using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). The results showed that the double inner diffusion layer was formed on Al coatings treated at 700[Formula: see text]C. And the single inner diffusion layer with uniform composition distribution could be formed on Al coatings treated at 950[Formula: see text]C. The Al-based composite coating prepared by thermal diffusion treatment at 950[Formula: see text]C had a dense and thick [Formula: see text]-Al2O3 surface layer, and it exhibited good high-temperature oxidation resistance.