In-depth Analysis of Laser Cladding Process: Principles, Classification and Material Selection

Laser cladding technology represents a cutting-edge surface engineering technique. Its principle lies in carefully positioning a chosen coating material onto the surface of the substrate in diverse filler forms. As a high - energy laser beam irradiates the area, not only does the coating material melt, but also a thin layer of the substrate's surface is melted simultaneously. Through rapid solidification, a surface coating with an extremely low dilution rate is created. This coating forms a metallurgical bond with the substrate material, which is crucial as it can significantly enhance multiple properties of the substrate surface. For instance, it can greatly improve wear resistance, allowing components to endure more friction; boost corrosion resistance, protecting materials from chemical attacks; enhance heat resistance and oxidation resistance, enabling parts to operate in high - temperature and oxidative environments; and even modify electrical properties.

According to the nature of the laser cladding material and the way it couples with the laser beam, common laser cladding technologies can be categorized. Coaxial powder feeding laser cladding technology typically employs a semiconductor fiber output laser and a disc - type gas - carrying powder feeder. The cladding head features a circular spot design with central light output and either annular powder feeding or multi - beam powder feeding around the beam, along with a dedicated protective gas channel. During the cladding process, the powder beam, laser beam, and protective gas flow converge at a single point, creating a molten pool at the focal point. As the cladding head and the workpiece move relative to each other, a continuous and high - quality coating is gradually formed on the workpiece surface. Paraxial powder feeding laser cladding technology, also known as lateral powder feeding laser cladding technology, has its own unique characteristics in the powder - feeding and beam - coupling mechanisms. High - speed laser cladding technology, sometimes referred to as ultra - high - speed laser cladding technology, focuses on achieving faster coating deposition rates while maintaining coating quality. High - speed wire laser cladding technology utilizes wire - shaped materials, presenting a different approach compared to powder - based cladding methods. Each of these classification methods has its own application scenarios and advantages, making laser cladding a highly versatile and adaptable technology in various industrial fields.