Microstructure and corrosion performance of zeolite/MAO-coated Al alloy

ABSTRACT

For micro-arc oxidation (MAO) coating on aluminium alloys, the corrosion medium can permeate through the microvoids and cracks in it to decrease its corrosion resistance. In this study, a method of two-steps hydrothermal synthesis has been developed to prepare a composite coating by the synthesis of zeolite film on MAO-coated Al alloy substrate. The zeolite crystals are well intergrown into a continuous film and the micro defects in the MAO coating are sealed. This kind of composite coating can provide excellent long-term corrosion protection to Al alloy substrate. The effect of the first-step hydrothermal synthesis on the microstructure of the MAO coating and zeolite film has been studied.

KEYWORDS:

• Aluminium alloy
• coating
• corrosion protection
• Zeolite
• micro arc oxidation
• hydrothermal synthesis

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors wish to thank financial support by the National Key Research and Development Program of China [grant number 2016YFB0300901].