Study on the characteristics and mechanism of pulsed laser cleaning of polyacrylate resin coating on aluminum alloy substrates

The behavior of paint removal with a pulsed laser has been investigated using an Nd:YAG fiber laser. Experimental and theoretical analyses are conducted to reveal the underlying mechanism of the paint removal. The results show that the depth, radius, and volume of the pit formed by a single pulse become larger with increases in the energy density. The ideal parameters for the complete removal of paint have been achieved. During the paint removal, burning occurred over the surface, and the variation in element content has been attributed to the absorption of laser energy. Under the action of the pulsed laser, there was breakage and rearrangement of chemical bonds such as C − C , C − N , and C − O in the molecular chain of the polyacrylate paint coating. Through these analyses, the paint removal mechanism was shown to be based on chemical bond breakage, combustion, and mechanical action provided by the thermal expansion and plasma shock.