Effect of different laser energy densities on the corrosion resistance of aluminum alloys

Abstract

Purpose Laser cleaning, as a new type of cleaning technology, has the advantages of environment-friendliness, better selectivity, better controllability and higher efficiency compared to traditional chemical cleaning or grinding. This paper aims to use ultra-fast surface laser cleaning equipment built in laboratory to study the influence of different energy density (7.6, 11.5 and 15.3 J/cm2) on corrosion resistance of the aluminum alloy A7N01P-T4, a high-speed train body material. Design/methodology/approach SEM, white light interferometer, EDS and XPS were used to analyze the surface morphology, roughness, element content and oxide layer composition of aluminum alloy before and after cleaning. The corrosion resistance was studied by electrochemical experiments and exfoliation corrosion experiments. Findings The results showed that new oxide scale was formed on the surface after laser cleaning. The changes of surface roughness and chemical composition of oxide scale made a significant influence on corrosion behaviors. Better corrosion resistance was obtained with the energy density increased, and at the energy density of 11.5 J/cm2, aluminum alloy exhibited the best corrosion resistance. Research limitations/implications The paper only studies specific aluminum alloys and is not universal. Laser cleaning equipment is set up for the laboratory and has not yet been put into industrial production. Practical implications This paper indicated that ultra-fast laser processing was a new direction for the development of industrial equipment surface cleaning and carried out ultra-fast laser of aluminum alloy surface cleaning had certain research significance for its corrosion resistance. Social implications Compared with the conventional cleaning methods such as air abrasives grinding or chemical cleaning, laser cleaning has advantages of environment-friendliness, better selectivity, better controllability and higher efficiency. Laser cleaning can not only protect the environment, but also improve cleaning efficiency. Originality/value Changes in the surface of aluminum alloys after ultra-fast surface laser treatment were found, and the mechanism of changes in aluminum alloy corrosion properties was clarified.

Research Progress and Challenges in Laser-Controlled Cleaning of Aluminum Alloy Surfaces

“…The corrosion resistance of the aluminum alloy surface is improved after the oxide film or paint layer is removed by using a laser, and the corrosion resistance of the aluminum alloy is better than that obtained via mechanical cleaning. By comparing the substrate corrosion resistance and the mechanisms after the mechanical and laser cleaning, the research found that the aluminum alloy corrosion resistance after laser cleaning is higher than that obtained after mechanical cleaning because the grain size did not change [ 66 ]. However, the aluminum alloy was thermally oxidized after the laser cleaning, the surface was remelted, and the initial MgAl 2 O 4 on the aluminum alloy surface was decomposed to obtain a new nanostructured layer comprising MgO and Al 2 O 3 [ 67 ], with making the element distribution uniform and the refining of the grains [ 68 ].…”

Laser Descaling Area Recognition Method Based on LabVIEW and Machine Vision

“…Laser is regarded as one of the four major inventions of the 20th century and has shown excellent performance in many aspects. With the deepening of research on laser technology, laser technology has begun to be applied to industrial rust removal [9]. As a new type of cleaning technology, laser cleaning is widely used to clean rust, oxide film, paint, coating, oil, and so on.…”