Anodising with Cr6+ based chemicals has been widely used for surface treatment of Al alloys in aerospace for purposes including corrosion resistance and as a pretreatment for adhesive bonding. This project will focus on the development of an electrophoretic coating (e-coat) process for 7000 series Al alloys for applications on landing gear, which avoids Cr6+, for resistance to corrosion. This may also be extended to pretreatments for adhesion and other purposes in a modified form with further testing and validation.
A successful e-coat process would be extremely valuable because it will eliminate Cr6+ from the pretreatment process. The current process is two stage; Cr6+ anodising followed by painting. The proposed work will deliver a low risk replacement for the Cr6+ anodising pre-treatment AND/OR a higher risk one step anaphoretic e-coating process in which the anodising of the Al part is achieved in situ.