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Experimental design for electrochemistry study of niobium oxide layers in 3003 aluminum alloy

The plating is an option that the metalworking industry has been found to increase the corrosion resistance of metal parts, but this coating is toxic to humans and to the environment. To achieve a new surface treatment the experimental design may be applied to optimize the experiments, especially when there are many variables to obtain at the final product or process. The main objective of this paper is to use experimental design to obtain a ceramic coating based on niobium oxide over 3003 aluminum alloys and to compare it to the Cr (III) coating, in the same metallic substrate. The techniques employed were anodic potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy and mapping by energy dispersive spectroscopy. An experimental design 23was used, where the variables were sol-gel sink rate, settling time after immersion and emersion in the base solution of niobium oxide (molar ratios n/n citric acid/ethylene glycol 1:4 acid and niobium ammonium complex 10:1). A tendency on the responses of the surfaces was detected, suggesting that at 5 min of immersion and emersion time and speed of 18 cm/min, the film achieved a higher corrosion resistance. The results of potentiodynamic polarization and electrochemical impedance spectroscopy showed that the anodic film of niobium oxide is more resistant than the coating used industrially, so that new surface treatment becomes a replacement option for Cr (III) coating.

ceramic; coating; surface treatment


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