Laser brazing is a laser welding technology that utilizes a focused laser beam to create high-temperature liquid metal to form strong metallurgical bonds between joined parts. This article explores the principle of laser brazing, its advantages and disadvantages, and delves into the various components that constitute a laser brazing system.

Introduction to Laser Brazing

Laser brazing is a specialized laser welding technique that employs a laser beam as a heat source to melt welding wire, which then forms a high-temperature liquid metal. This liquid metal infiltrates the joint of the welded parts, creating a reliable metallurgical bond with the workpiece. Unlike traditional welding methods, laser brazing minimizes deformation, reduces the heat-affected zone, and allows for high depth-to-width ratios in the weld, making it ideal for various applications.

Principle of Laser Brazing

The core principle of laser brazing is to use a laser beam with a small focus diameter to heat and melt the welding wire. The focused beam accurately irradiates the surface of the welding wire, ensuring precise and efficient melting. The molten metal from the welding wire infiltrates the joint of the workpieces and forms a robust connection when cooled down. It is crucial to avoid severe erosion of the base metal during the brazing process.

Advantages of Laser Brazing

Laser brazing offers several advantages over conventional welding techniques, making it a preferred choice in various industries:

1. High energy density: The concentrated laser beam provides intense heat, enabling rapid and efficient melting of the welding wire.
2. Minimal deformation: Due to the precise heat application, laser brazing results in reduced distortion of the workpieces.
3. Narrow heat-affected zone: The small focus diameter ensures a minimal heat-affected zone, preserving the integrity of the surrounding material.
4. High depth-to-width ratio: Laser brazing allows for deeper and narrower welds, enhancing joint strength and integrity.
5. High welding speed: The quick and controlled heat input leads to faster welding processes.
6. Easy automatic control: Laser brazing can be easily automated and integrated into manufacturing systems, streamlining production.

Disadvantages of Laser Brazing

Though laser brazing offers significant advantages, it also has a few limitations that must be considered:

1. Poor welding seam bridging ability: The small focus diameter of the laser restricts its ability to bridge gaps between workpieces, necessitating precise alignment during setup.
2. Low energy conversion efficiency: The efficiency of laser energy conversion is relatively low, leading to higher energy consumption.

Components of a Laser Brazing System

A complete laser brazing system comprises several key components, each playing a crucial role in the brazing process:

1. Laser generator and cooling system: The laser generator produces the laser light used for brazing and is accompanied by a cooling system to manage heat dissipation and ensure the laser’s stable operation.
2. Laser brazed head: This component includes the collimation module, control module, focusing module, seam tracking module, and air curtain module, responsible for precise laser beam delivery and process control.
3. Wire feeding system: The wire feeding system ensures a steady supply of welding wire during the brazing process. A push-pull wire feeding mechanism ensures proper alignment and stable wire feeding speed.
4. Robot: The robot acts as the motion system and carries the laser brazing head, accessories, and related circuits. It executes the welding process and communicates with the control system to access welding process parameters.
5. Fixture: A fixture holds the workpieces securely in place during the brazing process, ensuring precise alignment and consistent results.
6. Dust removal system: This system removes any debris or fumes generated during the brazing process, maintaining a clean and safe working environment.
7. Control system: The autonomous process cabinet controls the sequential actions of the various components, including the robot, laser, brazing head, wire feeder, and preheating systems. It ensures smooth coordination and efficient operation of the entire laser brazing system.

Conclusion

Laser brazing is a laser welding technology that offers numerous advantages for joining various materials. Its high energy density, minimal deformation, and narrow heat-affected zone make it an attractive option for industries seeking precise and efficient welding solutions. Despite its limitations, laser brazing can be effectively integrated into automated manufacturing processes, revolutionizing production efficiency and product quality. As advancements in laser technology continue, we can expect further improvements in laser brazing capabilities, expanding its applicability across diverse industries.