It is well known that laser has the functions of cutting, drilling, scribing, welding and cleaning in the field of precision machining. For the automotive industry, laser cleaning is as indispensable as all other functional applications of laser.
Laser cleaning can replace the traditional cleaning methods before welding and after welding. It can precisely clean the welded metal parts of auto parts or the welded metal parts, and remove the paint from the repair parts in the auto aftermarket, which is satisfactory to customers in the auto manufacturing market.
Laser cleaning principle
The principle of laser cleaning is based on the thermal expansion effect of laser irradiation on the surface of the cleaned object: that is, using the difference of the laser energy absorption coefficient of a certain wavelength between the substrate and the surface pollutants, the substrate material and the surface pollutants absorb energy to generate thermal expansion. When the expansion force of the dirt is greater than the adsorption force of the dirt on the substrate, the dirt on the surface of the parts can be quickly and accurately ablated and removed, even in a large area, It will not have thermal effect on the bottom part, and the dirt will leave the surface of the object.Therefore, the obvious advantages of laser cleaning are as follows:
- Clean the oxide layer (iron oxide, beryllium oxide, etc.) on the metal surface to improve the corrosion resistance of the metal
- Paint removal and oil and grease removal on the surface of formed parts
- Surface coating and coating cleaning
- Optimize the surface conditions before welding
- Stable base fusion line interface
- Without medium and chemical reagent, the operation is dry and clean
- Immediate use before welding
- Structural treatment of expanded surface
- In addition, laser cleaning is very soft, and the process speed is obviously faster than other methods
Laser cleaning equipment
Nowadays, there are many types of laser cleaning equipment, which can be divided into gas, crystal or optical fiber from the medium.The most common laser equipment used for laser cleaning mainly consists of four categories, namely gas laser, such as excimer laser (UV and CO2 laser, which are far from IR), solid state laser (common are Nd: YAG laser and Ti: Sapphire, which are close to IR), and fiber laser, mainly doped with Y and ErhuoTh.The laser cleaning equipment can meet the requirements of cleaning the metal parts before and after welding. At the same time, it can be carried with the welding gun to clean while welding, greatly improving the welding efficiency and improving the quality of the welding parts.
Application demand of automobile industry
In the process of automobile manufacturing, the drawing lubricant or cooling lubricant and anti-rust oil used will pollute the automobile components and seriously reduce the quality of the subsequent high-energy bonding or bonding process. Among them, the welds and bonding in the powertrain components must meet strict quality standards. Therefore, the mating surface must be thoroughly cleaned.
Traditional cleaning methods, such as manual cleaning, acid cleaning, shot blasting, sandpaper grinding, etc., not only pollute the environment, can not achieve automation, time-consuming, and cause a waste of human resources.
For example, key welds on painted structural parts must be coated to facilitate inspection, such as using manual or electric tools, abrasives or chemicals, which will hide the problem area and cause further damage to the surface.
Laser cleaning welding rust
Laser cleaning has many advantages, such as no contact, no damage to the base material, green environmental protection, fast cleaning and automation. During the processing of auto parts and the manufacturing of the whole vehicle, the laser light source is used to accurately locate the oxide scale and other residual pollutants on the surface before and after the welding of galvanized sheet and aluminum alloy, and thoroughly clean them, so as to obtain powerful, gap-free and micro-crack welding and bonding, which can effectively improve the welding quality of products.
Laser paint removal
Selective paint removal is one of the many applications of laser cleaning. The surface of weathered parts after laser paint removal has been cleaned, so that fresh new coating can be applied on the appropriate primer.
In the automotive aftermarket, it is sometimes necessary to remove the top layer of paint while protecting the primer. In general, the weathering coating on the vehicle shall be thoroughly removed before applying new paint. Since the physical and chemical properties of the topmost paint are different from that of the primer, the power and frequency of the laser can be set to remove only the topmost paint. Since the laser has no mechanical, chemical or thermal effect on the primer, the primer remains intact, which ensures the corrosion resistance of the primer.
According to different applications, the pulse frequency, energy and wavelength of the laser must be accurately selected to clean, polish and ablate the target material. At the same time, it is necessary to prevent any form of damage to the base material.
The application of laser cleaning machine for polishing, surface cleaning and coating removal in the automobile industry is expanding rapidly. In addition to automobile industry, laser cleaning is also used in mold casting, precision instruments, shipbuilding, transportation and other industries.
About HGSTAR: HGSTAR is is a sub-brand of HGTECH.HGTECH the pioneer and leader of laser industrial application in China, and the authoritative provider of global laser processing solutions. We have comprehensively arranged laser intelligent machine, measurement and automation production lines, and smart factory construction to provide overall solutions for intelligent manufacturing.