Effect of surface finish on corrosion behavior of polished Al6061 alloy in simulated acid rain environment

Abstract

Aluminium and its alloys are considered as most favorable material in aerospace, automobile and marine industries due to its light weight and high strength to weight ratio. Outer body of the airplanes, ships, automobile etc. are usually made of aluminium and its alloys. The tensile and fatigue failure of a component is highly affected by the corrosion behavior of the material in different environments. Surface roughness of the specimens plays an important role in determining the corrosion behavior of material. In the situations like Covid-19 or while waiting for repairing, airplanes, cars, ships etc. stand idle for months in the rainy environments. As rain is acidic in nature, metal starts corroding when get in contact with it. In the present work, corrosion due to acid rain on the polished surface of as-cast Al6061 alloy is analyzed through simulated acid rain environment (pH = 4). The effect of surface roughness on the corrosion rate was also investigated. It was observed that corrosion rate decreases as the surface finish of the specimen increases.