COMPARISON OF TWO STAINING METHODS FOR ANODIZING IN ALLOY 6063 ALUMINUM PROFILES

Abstract

Aluminum stands out for being a light, corrosion-resistant, and recyclable metal, achieving wide coverage in the market. When incorporated into alloying elements, it is possible to acquire other desirable characteristics. Alloy 6063, intended for architectural purposes, has aesthetic, structural, and strength functions. This study aims to compare two different staining methods on the surface of anodized profiles of aluminum alloy 6063. Anodized finishing is performed through an electrolytic process using sulfuric acid as an electrolyte to change the surface layer of the material, ensuring a more resistant aluminum oxide film than that formed naturally. For decorative purposes, the anodic film coloration can be performed by several methodologies, including, in this case, the coloration by organic adsorption, with the use of aniline, and the electrolytic coloration, composed of tin sulfate salts, both for obtaining the black color. To compare, neutral saline mist tests, scanning electron microscopy analysis, determination of the anodic layer thickness, and immersion tests with 3.5 percent sodium chloride for 1000 hours. The results obtained highlight that both were shown to be resistant to corrosion due to the fact that they do not present corrosion points when exposed to the neutral saline mist test for 600 hours. In the immersion tests, both remained resistant to sodium chloride. Because both methodologies present satisfactory results in all tests, the quality of the applied stains is ensured, and it is found that they are equivalent when the parameters discussed are used.