## 1 Introduction  
In aerospace, vehicle transportation, petrochemicals, and other fields, to improve the high temperature resistance, oxidation resistance, wear resistance, and corrosion resistance of metal substrates, the coating is usually coated on the surface of metal substrates. In metal parts, after a long period of service, the surface of the coating will be aging, ruptured, or even peeling, such as in aircraft, which commonly use epoxy coating with an average life of about 4-5 years. To ensure the stability and safety of metal parts during use, it is necessary to completely remove the original coating to facilitate repainting of the metal surface [1, 2]. Traditional remanufacturing cleaning technology refers to the method of removing contaminants or coverings from the surface of an object by grinding, sandblasting, and using chemical reagents to restore the object to its original form. However, these methods have significant limitations in the coating cleaning process [3, 4, 5]. Mechanical grinding cleaning technology can easily damage the surface of the workpiece, and the efficiency is very low and cannot meet the high cleanliness and high precision cleaning requirements. Acid-base chemical cleaning technology can cause corrosion on the metal surface and easily lead to hydrogen embrittlement and other problems, which reduces the performance of the metal. At the same time, waste liquids will cause secondary pollution to the environment, water, and soil. In response to these situations, many new cleaning technologies have been invented and applied, such as molten salt cleaning technology,dry ice cleaning technology, supercritical CO\({}_{2}\) cleaning technology, and laser cleaning technology [6; 7; 8; 9]. Laser cleaning, as an efficient and green cleaning technology, has been widely investigated. The technique is to use continuous or pulsed laser irradiation to clean the surface of the workpiece. Most of the laser energy is instantly absorbed by the coating material, except for a small amount of laser energy that is lost due to thermal convection and thermal radiation. The temperature of the coating material rises rapidly to the vaporization temperature in a very short period of time, and the final removal of the coating from the substrate surface is achieved. Laser cleaning technology has the advantages of high cleaning accuracy, low environmental pollution, and low material damage, which are now widely used in various fields [10; 11; 12; 13; 14; 15]. In the future, it is expected to partially or completely replace traditional methods and become the most potential remanufacturing cleaning technology in the 21 st century. At present, research on laser cleaning technology mainly focuses on the cleaning mechanism, process law, and influence on the microstructure and properties of the substrate. In terms of cleaning mechanisms, [PERSON] et al. [16] used different parameters for laser cleaning of TiN coatings. By analyzing coating morphology, surface composition, and sample profile, research reveals the morphological change of the TiN coating after cleaning and the laser cleaning mechanism. [PERSON] et al. [17] studied the mechanism of pulsed laser paint removal from a microscopic perspective using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. [PERSON] et al. [18] introduced laser cleaning of blue polyurethane paint on an Al-Mg series aluminum alloy substrate using a nanosecond pulsed laser. It was found that ablation, spallation, and vaporization were the main cleaning mechanisms in the process of laser-cleaning paint. In terms of process research, [PERSON] et al. [19] studied the effect of laser pulse energy density on paint removal rate, and explored the change process of paint layer from removal to damage with the change of energy density. [PERSON] et al. [20] studied the effects of laser energy density, repetition frequency, and pulse width on the efficiency of laser rust removal. [PERSON] et al.