A Case Study on Ionic Compounds on the Aluminium 6061 Surface during Etching and Passivating Processes

Abstract

The surface treatment process for aluminium is extensive, encompassing many methods and techniques. This study utilises chemical etching and passivation chemicals as surface treatment processes for chemical cleaning. The corrosion-controlled procedure involves the application of a powerful etchant solution to eliminate undesirable layers of material. Additionally, passivation chemicals are utilised as coatings to enhance the corrosion resistance of aluminium surfaces. Following the chemical cleaning process, ion chromatography testing was conducted to verify the ionic compounds on the surface of the aluminium metal subsequent to its reaction with etching and passivation chemicals. Different approaches were employed to address the ionic compound deposition problem on the surface of aluminium 6061 metal. Results revealed that replacing existing chemicals with new ones is the best solution to reduce the reading below the specified limit. However,  one economically viable alternative for the chemical cleaning process is implementing an aeration process during rinsing, which offers greater economic efficiency compared to the substitution of chemicals entirely. Besides that, chemical cleaning via aeration procedure can mitigate the accumulation of ionic compounds on the material's surface.