Laser cladding repair technology uses a high-power density laser beam, and is controlled by a laser processing system under CNC control to form a very thin micro-melted layer on a designated part of the surface of the substrate. At the same time, specific ingredients are added in a preset or synchronous manner. Self-fluxing alloy powders, such as nickel-based, cobalt-based, and iron-based alloys, etc., spread evenly on the surface of the part in a molten state and reach a predetermined thickness, forming a good metallurgical bond with the slightly molten base metal material, and there is only a small amount of space between them. With a small dilution, in the subsequent rapid solidification process, a functional cladding material layer with predetermined special properties is formed on the surface of the part that is completely different from the matrix, thereby completely changing the surface properties of the material and enabling low-cost material surfaces to be obtained. Extremely high wear resistance, corrosion resistance, high-temperature resistance, and other properties. This process can repair holes and cracks on the surface of materials and can restore the geometry and performance of worn parts.

1. The cooling rate is fast (up to 106°C/s), which is a rapid solidification process. It is easy to obtain fine-grained structures or produce new phases that cannot be obtained in equilibrium, such as unstable phases, amorphous states, etc.;
2. The dilution rate of the coating is less than 5%, and it has a strong metallurgical bond or interface diffusion bond with the substrate to obtain a good cladding layer with controllable coating composition and dilution;
3. Using high power density and rapid cladding, the heat input, heat affected zone, and distortion are small and can be reduced to the assembly tolerance of the parts;
4. There are almost no restrictions on powder selection and high melting point alloys can be deposited on the surface of low melting point metals;
5. The thickness and hardness range of the cladding layer is wide, and the cladding thickness can be within 20 mm, and the cladding layer has a hardness range of 18-60HRC;
6. The process is controlled by CNC, and the beam aiming can clad hard-to-reach areas. The operation is automated, convenient, flexible, and highly controllable.

1. High speed. The large depth and small deformation;
2. Laser welding can be performed at room temperature or under special conditions, and the welding equipment is simple to install. For example, when a laser passes through an electromagnetic field, the beam will not shift; the laser beam can be welded in vacuum, air, and certain gas environments, and can be welded through glass or materials that are transparent to the beam.
3. It can weld refractory materials such as titanium, quartz, etc., and can weld special-shaped materials.
4. After the laser beam is focused, the power density is high. When welding high-power devices, the aspect ratio can reach 5:1 and up to 10:1.
5. Micro welding possible. The laser beam can obtain a very small spot after being focused, and can be positioned accurately, and can be used for assembly welding of micro and small workpieces in mass automated production.
6. It can weld inaccessible parts and implement non-contact long-distance welding, which has great flexibility.
7. The laser beam can easily split the beam in time and space and can perform multi-beam simultaneous processing and multi-station processing, providing conditions for more precise welding.

However, laser welding also has certain limitations:

• The welding assembly requires high precision, and the position of the beam on the workpiece must not deviate significantly. This is because the spot size after focusing the laser is small and the welding seam is narrow. If the workpiece assembly accuracy or beam positioning accuracy does not meet the requirements, it is easy to cause welding defects.
• The purchase cost of lasers and related systems is relatively high, and the one-time investment in purchasing them is large.