Process and properties of spray-aluminized coating on cast iron

Abstract

Aluminum-based coatings were prepared by flame spraying. After remelting and diffusion treatment, the phase, composition, friction and corrosion resistance were analyzed experimentally by using scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer, wear tester. The results indicate that the surface phase consists of Al and FeAl3, inner layer phase mainly contains FeAl 3 and Fe2 Al5. The coating has higher micro-hardness than the underlying material, with a maximum of up to HV 950. In an experiment of high-temperature oxidation at 800℃ and 900℃, the spray-aluminized samples show almost no weight gain, and the antioxidant properties of cast iron improve substantially (by dozens of times). In addition, the samples show excellent wear and corrosion resistance.

Keywords

• cast iron
• flame spraying
• aluminizing
• diffusion treatment
• high-temperature oxidation