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

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.

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.

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.

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.

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.

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.

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.