Laser welding is the use of high-energy laser pulses to locally heat materials within a small range. The energy radiated by laser diffuses into the interior of the material through thermal conduction, causing the material to melt and form a specific molten pool, which is a new welding method.

The advantages of laser welding

1. The input heat can be minimized, the metallographic variation range of the Heat-affected zone is small, and the deformation caused by heat conduction is also the lowest.

2. The welding process parameters of single pass welding for 32mm thick plates have been verified, which can reduce the time required for thick plate welding and even save the use of filler metal.

3. No need to use electrodes, no need to worry about electrode contamination or damage. And since it does not belong to the contact welding process, it can minimize the wear and deformation of the machine tool.

4. The laser beam is easy to focus, align and be guided by optical instrument, can be placed at a proper distance from the workpiece, and can be diverted between machines or obstacles around the workpiece. Other welding methods are limited by the aforementioned space and cannot be fully utilized.

5. The workpiece can be placed in a confined space (vacuum or internal gas environment can be controlled).

6. The laser beam can be focused on a small area and can weld small and tight components.

7. The range of weldable materials is wide, and various heterogeneous materials can also be interconnected.

8. Easy to achieve automation of high-power welding, and can also be controlled by digital or computer.

9. When welding thin wires or wires, there is no trouble of arc welding reflow.

10. It is not affected by magnetic field (easy for arc welding and electron beam welding), and can accurately align weldments.

11. Two metals with different physical properties (such as different resistance) can be welded

12. No vacuum or X-ray protection is required.

13. If perforated welding is used, the depth to width ratio of the weld bead can reach 10:1

14. This device can switch the transmission of laser beams to multiple workstations.

Disadvantages of laser welding

1. The position of the weldment must be very precise and within the focusing range of the laser beam.

2. When a fixture is required for a weldment, it must be ensured that the final position of the weldment is aligned with the welding point that the laser beam is about to strike.

3. The maximum weldable thickness is limited. For workpieces with a melting depth exceeding 19mm, laser welding is not suitable for production lines.

4. For materials with high reflectivity and high thermal conductivity, such as aluminum, copper, and their alloys, laser can alter their weldability.

5. During medium to high energy laser beam welding, a plasma controller is required to remove ionized gas around the molten pool to ensure the reproduction of the weld seam.

6. The energy conversion efficiency is too low, usually below 10%.

7. The weld bead solidifies rapidly, which may lead to porosity and embrittlement issues.

8. Expensive equipment

In order to eliminate or reduce the defects of laser welding and better apply this excellent welding method, some composite welding processes using other heat sources and lasers have been proposed, mainly including laser and arc, laser and plasma arc, laser and induction heat source mixing, etc. Welding, dual laser beam welding, and multi beam laser welding. In addition, various auxiliary process measures are proposed, such as laser wire filling welding (which can be subdivided into cold wire welding and hot wire welding), external magnetic field assisted enhanced laser welding, shielding gas controlled weld pool depth laser welding and laser assisted friction stir welding.
 

About HGTECH

HGTECH is the pioneer and leader of laser industrial application in China, and the authoritative provider of global laser processing solutions. We comprehensively layout the construction of laser intelligent equipment, measurement and automation production lines, and smart factories to provide an overall solution for intelligent manufacturing.

We deeply grasp the development trend of manufacturing industry, constantly enrich products and solutions, adhere to exploring the integration of automation, informatization, intelligence and manufacturing industry, and provide various industries with laser cutting systems, laser welding systems, laser marking series, laser texturing complete equipment, laser heat treatment systems, laser drilling machines, lasers and various supporting devices The overall plan for the construction of special laser processing equipment and plasma cutting equipment, as well as automatic production lines and smart factories.