Effect of Sealants and Homogenization on Corrosion Resistance of Anodized AA535 Aluminum-Magnesium Casting Alloy)

The purpose of this engineering project is to investigate the effect of homogenization on the mechanical properties and corrosion resistance of AA 535 aluminum-magnesium casting alloys by homogenizing at 400 ^oC for 5, 6, and 7 hours. The homogenization results in decreasing micro shrinkage and percentage of intermetallic compounds of the alloys due to dissolution of alloying elements. It also has better mechanical properties in terms of hardness and tensile strength. The homogeneous alloy is anodized and then sealed with organic substances, such as stearic acid and triethanolamine, to enhance corrosion resistance. The anodized oxide film layer was found to be more uniform and thicker than non-homogenized alloys, especially if sealed with stearic acid. Corrosion resistance testing with salt spray revealed that a homogeneous alloy that has been anodized and sealed with two organic substances, is a stearic acid and triethanolamine that is more corrosion resistant than non-homogenized alloys.