Optimization of Aluminum Anodizing and Coloring Process Employing Organic Pigment

Abstract

The process of aluminum anodizing forms an oxide layer constituted of nanotubes where it is possible to insert compounds, amongst these are the pigments and dyes. This study has as its main aim to study the behavior of aluminum alloy 6000, anodized and dyed with monolite red in Na2SO4 0.5 mol L-1 and pH = 4. The techniques employed were: anodic potentiostatic polarization, open circuit potential, chemometry, polarization resistance and optical micrograph. The factorial planning was proposed using four variables (anodizing time, current density, electrolyte concentration, and dye), the response to the planning was the charge transfer resistance. Polarization curves revealed that the anodized and dyed aluminum samples are much more resistant than the non-anodized aluminum. Optical microscopy analyses demonstrated that the dissolution of dye occurs in the solution, but not enough to break the film. As the main result, efficient coloring of aluminum parts was verified with reduction in costs in relation to the energy employed in the process, associated to reduction in time spent for the anodizing process, which makes it suitable to increase industrial production of dyed aluminum parts.

Optimization of Hydrophobic Coating Production by Pechini Method on Modified Aluminum Surface

“…For the anodization treatment, a sulfuric acid solution (Neon ® , 10% m/v) was used as the electrolyte, and a constant current of 20 mA cm -2 was applied for 15 minutes using a Minipa ® MPL-3303M power source with digital control. The values of these parameters were chosen based on the optimized conditions in previous studies [44]. The system for this process consisted of the prepared substrate as the anode and a similar plate of aluminum as the cathode, immersed in the electrolyte in a 250 mL polymeric vessel.…”