Effect of prior sputter deposition of pure aluminium on the corrosion behaviour of anodized friction stir weld of dissimilar aluminium alloys

The effectiveness of the anodic oxide layer formed by a novel processing technique (pre sputter-deposition prior to anodizing) for the corrosion protection of friction stir welds of dissimilar aluminium alloys has been investigated. Two categories of corrosion attacks were observed: a pre-anodizing; and a post-anodizing attack. The novel processing technique prevented the pre-anodizing attack whilst the post-anodizing attack was significantly minimised, and the galvanic current density values between the two alloys were reduced to insignificant values.