Laser cleaning technology refers to the use of high-energy laser beams to irradiate the surface of the workpiece to instantly evaporate or peel off the dirt, rust spots or coatings on the surface, and effectively remove the surface attachments or surface coatings of the cleaning object at high speed, so as to achieve a clean process. It is a new technology based on the interaction effect of laser and matter. Compared with traditional cleaning methods such as traditional mechanical cleaning method, chemical corrosion cleaning, liquid solid strong impact cleaning, and high-frequency ultrasonic cleaning, it has obvious advantages. It is efficient, fast, low cost, small thermal load and mechanical load on the substrate, non-destructive cleaning; recyclable waste, no environmental pollutants, safe and reliable, does not damage the operator's health certificate, can remove a variety of different thickness, different The sub-cleaning process of the coating of the components is easy to realize automatic control, and realize long-distance remote control cleaning, etc.
Compared with the traditional cleaning process, laser cleaning technology has the following characteristics:
(1) It is a dry "dry" cleaning that does not require cleaning fluid or other chemical solutions, and its cleanliness is much higher than that of chemical cleaning processes;
(2) The range of cleaning dirt and the range of applicable substrates is very wide;
(3) By adjusting the parameters of the laser process, the pollutants can be effectively removed without damaging the surface of the substrate, and the surface can be restored as new;
(4) Laser cleaning can easily realize automatic operation;
(5) The laser cleaning equipment can be used for a long time and the operating cost is low;
(6) Laser cleaning technology is a "green" cleaning process, and the eliminated waste is solid powder, small in size, easy to store, and basically does not cause pollution to the environment.
The process of pulsed laser cleaning relies on the properties of the light pulses produced by the laser, based on photophysical reactions caused by the interaction between the high-intensity beam, the short-pulse laser, and the contamination layer. Its physical principles can be summarized as follows:
a: The beam emitted by the laser is absorbed by the contamination layer on the surface to be treated.
b: The absorption of large energy forms a rapidly expanding plasma (highly ionized unstable gas), which generates a shock wave.
c: The shock wave breaks the contaminants into fragments and is rejected.
d: The optical pulse width must be short enough to avoid heat build-up that would destroy the surface being treated.
e: Experiments show that plasma is generated on the metal surface when there is oxide on the metal surface.
