Study on the Structure and Corrosion Resistance of Chromatic Ti-Zr Based Conversion Layer on 6063 Aluminum Alloy

In order to obtain chromatic Ti-Zr conversion layers with good performance,the conversion solution formula of 6063 aluminum alloy was obtained by orthogonal test consisting of hexafluorotitanic acid,hexafluorozirconic acid,coating former and organic acid.The surface morphology,composition and corrosion resistance of the conversion films were analyzed.The results show that the conversion layer is yellow and uniformly continues and contains Ti,Zr elements.However the corrosion potential and the corrosion current of conversion layer decrease obviously than bared 6063 aluminum alloy.It reveals that the titanium-zirconium solution can further suppress the catholic reaction of aluminum alloy,thus improve the anti-corrosion behavior of aluminum alloy efficiently.