A Fundamental Study on the Application of Laser Cleaning Process for Removing Vaporizing Press Oil from Aluminum Surfaces

Despite pre-cleaning with vaporizing press oil, aluminum alloys, widely employed in industry, often retain oil residues and cause various problems during or after machining and assembly operations. Laser cleaning has emerged as a n eco-friendly, non-contact, and highly controllable surface treatment technique that selectively removes contaminants from metal surfaces. In this study, the cleaning technology was applied to vaporizing press oil on an A3003 aluminum alloy surface and was systematically investigated with variable pulsed laser processing parameters. The removal characteristics were analyzed by FTIR to identify the disappearance of lubricating oil characteristics as C-H vibrational peaks and by SEM-EDS to assess microstructural and compositional changes. The results demonstrated that complete removal of lubricant residues without substrate damage was achieved under the optimized condition of -3 mm defocus distance, 75 % overlap ratio, three scans, and 100 W average power. However, when the overlap ratio exceeded 75% or the laser power exceeded 200 W, excessive thermal accumulation induced localized burning and carbonization, resulting in reduced cleaning efficiency. The optimized parameters derived in this study provide a fundamental guideline for the development of environmentally sustainable laser cleaning processes for aluminum alloy heat-ex changer components.