Cladding effect
Laser powder feeding 3D printing remanufacturing technology is to use a high-power laser beam to focus on the optical element to obtain a very high energy density, which instantly melts the surface of the substrate and simultaneously melts the alloy powder that is preset or automatically sent to the substrate surface in synchronization with the laser beam , To obtain a dense coating combined with the base metallurgy. The bonding strength is generally not lower than 95% of the original matrix material. The substrate material can be micro-melted on the surface during laser processing. The micro-melt layer is 0.05-0.1 mm, and the heat-affected zone of the substrate is extremely small, generally 0.05-0.5 mm. Both the cladding layer and the matrix have no coarse casting structure, the cladding layer and its interface are dense, the grains are fine, there are no defects such as voids and inclusion cracks. During laser processing, the temperature of the substrate does not exceed 80 ° C. The deformation after laser processing is calculated at 0.01mm. After the cladding, the stress is released after heat treatment. The deformation will be calculated at 0.001mm, which is completely negligible.
Because the blade tip thickness changes, the middle thickness is the largest, and greater power is required during cladding. If the laser is cladding at the same power, the thinnest part of the two ends will be melted by this larger power, and it cannot play a repairing role. Therefore, in order to obtain the corresponding cladding width without melting the material at both ends of the blade, variable power cladding is used. Because the two ends of the blade are particularly thin, the thickness at both ends of the 8-stage blade is only 0.2mm. Undercutting is easy to occur during laser cladding, so special treatment is required at both ends to solve the undercutting problem. In low-power cladding, it is necessary to rely on a laser coaxial imaging system for accurate comparison. At present, the rotor blades of the compressor that have been repaired work well.