In order to obtain the change law of surface morphology of aluminum alloy after laser cleaning

a laser with pulse width of 150 ps was used to clean the oxide film on the surface of aluminum alloy. The surface morphology

micros-tructure

composition and roughness of the laser-cleaned aluminum alloy were observed and tested by optical microscope

scanning electron microscope

energy spectrometer and roughness meter. It is found that after laser cleaning

the oxygen content and roughness of the surface of aluminum alloy decrease

and the oil and oxide film are washed off

forming regular cleaning traces

which are composed of tidal tissues and tiny particles. When the energy density is greater than 1.53 J/cm

2

the surface temperature of the aluminum alloy is high

and the generated plasma gas impacts the surface of the micro-melted aluminum alloy

making the trace deeper and increasing the area and time of contact between oxygen in the air and high-temperature aluminum alloy

thus resulting in a more severe oxidation phenomenon

so that the laser cleaning traces and secondary oxidation phenomenon of the aluminum alloy surface increase when the energy density increases.