Optimization of Surface Laser Cleaning Parameters of 7050 Aluminum Alloy after Anodizing

Traditional surface cleaning methods such as physical method, chemical method, etc., have various problems in efficiency, damage, pollution, etc. The new laser cleaning technology can improve the performance on the basis of solving these problems. However, the premise of achieving the above advantages is the use of appropriate laser process parameters. If the parameters are not set up, it is impossible to remove pollutants and even damage components, so it is necessary to optimize the parameters to reduce the impact of laser on the matrix. In order to determine the process parameters of laser cleaning 7050 aluminum alloy anodic oxide films. The surface of 7050 aluminum alloy after anodizing was cleaned by Gaussian pulse fiber laser. The optimal parameters of removing anodized films were investigated by changing the laser power and scanning times. Roughness measuring instrument, scanning electron microscope, friction and wear testing machine, white light interferometer, Vickers hardness tester, X-ray residual stress analyzer, electrochemical workstation and other instruments were used to analyze and study the properties of different parameters after laser cleaning of aluminum alloy anodic oxide films. The experimental results showed that the oxide film on the surface of the sample cleaned by reasonable laser parameters was completely removed, and there was no obvious damage to the matrix. Only when the laser power reached the cleaning threshold for removing the anodized film, could the anodized film be removed. When the cleaning threshold was not reached, the laser could only act on the surface of the oxide film. Excessive cleaning would destroy the matrix. The sample performance of low power multiple scanning was better than that of high power single scanning. At the same time, it was found that excessive laser scanning should be avoided as far as possible in the process of laser cleaning, with a maximum of two scans and the power should be reduced. The microhardness of the samples with the best single scan and the best double scans was increased to 182.86HV and 187.36HV, respectively, which were increased by 7.9% and 10.6% compared with the matrix. The self-corrosion current density of the samples with the best single scan and the best double scans was from 10–4 to 10–5 relative to the matrix, and the difference between the two was only 10–6. The wear depth of the samples with the best single scan and the best double scans was reduced by 6.3 μm and 6.8 μm respectively, and the friction coefficient was less than 0.3. The wear mechanism of the samples before and after laser cleaning was the mixed wear of abrasive wear, adhesive wear and oxidation wear, and the difference may lie in the proportion of the three and the time and location of the occurrence. The cleaning threshold of 7050 aluminum alloy anodic oxide films is between 150 W and 180 W, and the best parameter is 170 W scanning twice. Under suitable laser cleaning parameters, the properties of the material are better than the matrix. The mechanism of Gauss pulse laser cleaning of 7050 aluminum alloy anodic oxide films is mainly vibration mechanism, and ablation mechanism is auxiliary. © 2025 Chongqing Wujiu Periodicals Press. All rights reserved.