What is laser cladding technology?
Laser cladding technology is an advanced technology of metal surface strengthening that began to be studied and developed rapidly in the 1980s. The principle is to use high-energy, high-speed laser beam radiation to feed the coating powder, and quickly melt a thin layer on the surface of the substrate at the same time, the beam is removed and self-cooling, so that the particles and the body form a metallurgical combination of the surface coating. The cladding layer is characterized by high binding force, hardness, low porosity, good corrosion resistance and organizational stability, and high production efficiency.
What are the advantages of laser cladding technology?
Compared with vacuum brazing, vacuum coating welding, tungsten inert gas welding (TIG) and other methods to repair blade cracks, laser cladding is a process of ultra-fast heating and ultra-fast cooling, which has the advantages of less heat input to the substrate, small heat affected zone, fine cladding layer structure and easy automation. At present, laser cladding technology has become the preferred aero engine turbine blade repair technology in developed countries.
How does laser cladding repair cracks?
In the process of use, the turbine blades of the engine are subjected to large aerodynamic force and unstable pulsating load, and in the high-temperature gas, the cold and heat change is large, and the temperature is not uniform. For the blades that suffer thermal fatigue caused by repeated thermal shock, the main repair method is to use powder of the same material as the matrix and laser cladding to make the blades have uniform fine crystal structure to improve their performance.
The nickel-based alloy powder is suitable for components requiring local wear resistance, heat corrosion and thermal fatigue resistance, and the repair process is roughly as follows:
1. Before repair, the blade is tested, and the method of non-destructive testing can be used to detect the specific location, shape, size, etc., of the blade crack to determine whether it has repair value.
2. Ultrasonic cleaning of the blade surface.
3. Clean the crack, and completely remove the oxide film and dirt at the crack of the blade, so that the cladding metal powder can wet the crack surface of the blade and combine with the matrix metal metallurgy. For this kind of oxide film, the main removal methods commonly used in the world are fluoride reaction removal and mechanical removal.
4. The application of laser cladding repair system to the blade crack laser cladding repair, that is, the laser beam is irradiated at the crack, while the powder feeder continues to send powder (repair solder metal powder), using the high energy of the laser beam, constantly melt repair solder powder and blade matrix material, so that the repair solder and blade matrix tightly together, so as to achieve the purpose of repair.
5. Apply a mechanical method to repair the cracked surface of the repaired blade to make it meet the surface quality requirements.
6. Restore the blade surface protection system.
7. Quality inspection of repair parts.
Xi'an Guosheng Laser Technology Co., Ltd. is a high-tech enterprise specializing in R&D, manufacturing and sales of automatic laser cladding machine, high-speed laser cladding machine, laser quenching machine, laser welding machine and laser 3D printing equipment. Our products are cost-effective and sold domestically and abroad. If you're interested in our products, please contact us at bob@gshenglaser.com.