Research Development of Aluminium Alloy with Chromate-free Passivation

The passivation treatment can improve the corrosion resistance of aluminium alloy effectively.The chromate passivation is one of the important methods to improve the corrosion resistance of aluminium alloy.Because of the toxicity and environmental pollution for chromate treatment,the low or non toxic passivation treatment becomes imperative.The exploitation of chromate-free passivation which has better practicability and environmental friendly is the developing direction.Several chromate-free passivation methods for aluminium alloy,which consist of molybdatein passivation,zirconate passivation,titanium salt passivation and rare earths passivation,were summarized.