With the development of industry, the corrosion and wear of mechanical surfaces have become an important issue restricting industrial production. How to enhance the surface strength of machinery has become one of the more concerned issues in industrial development. There are many surface repair and strengthening technologies, among which metal thermal spraying technology and laser cladding technology are commonly used for repair.
Metal surface strengthening is the use of laser beams to spray (melt) alloy materials onto the surface of the substrate, resulting in alloy coatings with different compositions and properties from the substrate material. Laser technology can be used for surface spraying or surface cladding.
The main difference between thermal spraying and laser cladding is: Thermal spraying technology uses a laser beam to heat a coating material to a molten state, which is then accelerated and sprayed onto the surface of the substrate by compressed gas. After deposition, a metal coating is formed, and its main characteristics are as follows:
1. The coating has high bonding strength and density; 2. The surface roughness of the coating is low; 3. The spraying efficiency is relatively high and the operation is convenient; 4. Has strong chemical stability performance.
Laser cladding is the process of melting coating materials and substrate surfaces, and rapidly solidifying them. The cladding layer forms a metallurgical bond with the substrate surface, forming a repair layer. Its main characteristics are as follows: 1. Fast cooling speed; 2. Low dilution rate of coating; 3. Low heat input and distortion; 4. The thickness range of the cladding layer is relatively large; 5. High cost-effectiveness, easy to achieve automation.