Experimental and numerical simulation analysis of laser paint removal of aluminum alloy

This work simulates the process of nanosecond pulse laser cleaning of acrylic paint on 7075 aluminum alloy surfaces by establishing a finite element, three-dimensional, numerical, transient model. The resulting temperature field and ablation depth for the laser-cleaned paint layer are analyzed by changing the energy density and scanning speed of the Gaussian heat source, which are also verified experimentally. The results show that the scanning speed affects the cleaning efficiency as the overlap rate; a slower scanning speed gives a lower cleaning rate. An acceptable cleaning efficiency is obtained when the spot overlap rate is 50%. The maximum temperature of the paint and the substrate surface increases linearly with laser energy density. When the energy density reaches 24 J/cm2, the paint material in the irradiated laser area of the alloy surface is completely removed, and the ablation depth of the aluminum alloy base is 48.2 μm. Aluminum alloy cleaning experiments at a laser energy density of 24 J/cm2 and a scanning speed of 2000 mm/s can obtain a metal surface that meets the standards of painting processes. This article provides theoretical simulations of laser cleaning for paint removal and has theoretical guidance for cleaning operations.