Abstract
In this work we propose a statistical approach which optimizes the operating parameters of tartaric sulfuric acid anodizing (TSA) and MnVO oxyanion sealing on Aluminium 7075 alloy. Here we used Response Surface Methodology and Taguchi Design to find an optimum condition for the surfaces with maximum corrosion resistance. This manuscript aims to provide a mathematical model which correlates coating thickness to anodizing parameters like voltage, temperature, sulfuric acid concentration, agitation, duration and tartaric acid concentration. Such combinatory approach has not been introduced or reported till now in optimizing the sealed anodic oxide layer to exhibit improved corrosion resistance. The surface of optimized TSA-MnVO sealed anodized coatings qualified 1000 h of salt spray exposure. The optical microscopic images clearly show the coating has excellent barrier and self-healing corrosion resistance behaviour in NaCl environment. The X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy of sealed anodized surface confirmed the presence of polymerized decavanadate species. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization test results revealed the resistance value of the coating is >15 MΩcm2 and corrosion current density (icorr) value of 4.5 nA/cm2 respectively, indicating excellent protective behaviour of the optimized coating in aggressive chloride environment.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
