Diamond tools, due to their extremely high hardness, wear resistance, and excellent cutting performance, are widely used in stone processing, concrete cutting, and machinery manufacturing. In the structure of a diamond tool, the connection method between segment the base material is a crucial factor determining its performance, safety, and service life. With advancements in industry technology, diamond tool welding processes have evolved from high-frequency welding (brazing) to laser welding.
Long ago, diamond saw blades and other diamond tools commonly used high-frequency welding technology. This process primarily utilizes high-frequency induction heating to melt silver-based or copper-based brazing filler metals, thereby welding the diamond segments to the steel base. However, high-frequency welding is a brazing connection method, requiring an intermediate solder layer for connection between the cutting head and the base material, which introduces significant technical limitations. First, the weld strength is limited by the properties of the brazing filler metal, posing a risk of segments detachment under high-impact or high-load cutting conditions. Second, the heat resistance of the brazing filler metal is limited; when the temperature is too high during cutting, the solder may soften or even melt, affecting the stability of the connection. This problem is particularly pronounced in dry or high-speed cutting conditions, thus many traditional brazed saw blades can only be used in wet cutting environments.
Furthermore, high-frequency welding has a relatively large heating range, which easily creates a heat-affected zone (HAZ), potentially affecting the stability of the saw head structure and causing deformation of the substrate, further limiting the improvement of tool performance. With the development of applications in industries such as stone quarrying and reinforced concrete cutting, the market demands higher safety, stronger high-temperature resistance, and longer service life for diamond tools. Therefore, laser welding technology has gradually entered the diamond tool manufacturing field. Laser welding uses a high-energy laser beam to concentrate heat the connection area between the saw head and the steel substrate, causing them to melt locally and form a direct metallurgical bond without the need for intermediate solder. This method creates a more robust integral structure between the saw head and the substrate, significantly improving weld strength.
Compared to traditional high-frequency welding, laser welding has several advantages. First, due to the direct fusion connection, its weld strength is generally higher than that of brazing, greatly reducing the risk of saw head detachment and improving tool safety. Second, laser welding has concentrated heat and a small welding area, significantly reducing the HAZ, which helps maintain the stability of the internal structure of the saw head. Secondly, due to the absence of a low-melting-point brazing filler layer, laser welding tools can withstand higher operating temperatures, making them suitable not only for wet cutting but also for stable operation in dry cutting environments. Laser welding requires a high degree of automation. Despite its numerous advantages, laser welding has not yet been widely adopted due to various external influencing factors.
Overall, the diamond tool industry currently exhibits a development pattern where high-frequency welding and laser welding coexist: high-frequency welding is still mainly used in general stone processing and cost-sensitive products, while laser welding is gradually becoming the mainstream technology for high-end diamond tools, widely used in concrete cutting, road construction, and other fields. As the cost of laser equipment gradually decreases and the level of automated manufacturing continues to improve, the application rate of laser welding technology in diamond tool manufacturing will further increase in the future.