Advantages and disadvantages of laser welding

Advantages of laser welding: low cost, no need for post-welding correction and cleaning, multi-channel simultaneous or time-sharing welding, high power density and high production efficiency; Disadvantages: defects, large investment, difficult control of laser wire filling welding process, high requirements on workpiece assembly accuracy and limited application.

1, advantages:

Compared with traditional spot welding, the lap edge is shorter, which is beneficial to body weight reduction and cost reduction. The heat input is small, the heat affected zone is small, the shrinkage deformation of the workpiece is small, and post-welding correction is not needed. High weld strength, fast welding speed, narrow weld and good surface condition, and no need for post-welding cleaning. For the parts that are difficult to reach by ordinary methods, long-distance, multi-channel simultaneous or time-sharing welding can be realized through optical fiber.

The laser beam has small laser focus and high power density, and can weld some alloy materials with high melting point and high strength. High production efficiency, stable and reliable processing quality and good economic and social benefits.

2. Disadvantages:

Weld solidification is relatively fast, and there may be defects such as porosity and embrittlement. Because of the large splash, the weld seam of penetration welding is rougher than that of brazing, but the strength is much stronger than that of ordinary spot welding. Compared with other welding methods, the cost of laser and its related systems is higher, and the initial one-time investment is larger.

It is difficult to control the laser welding process. Laser wire filler welding belongs to fusion welding, and the focused light spot is irradiated on the workpiece and welding wire respectively. The molten pool is small, so it is very important to accurately control the relative position of the filament in order to make the continuous feeding wire melt evenly.

Because of the small size of laser focused spot and narrow weld, laser welding requires high assembly accuracy of workpiece. The position of the weldment must be very accurate, and the beam position on the workpiece must not be significantly offset, and it must be within the focus range of the laser beam. If the workpiece assembly accuracy or beam positioning accuracy can not meet the requirements, it is easy to cause welding defects.

In addition, due to the above shortcomings, higher requirements are put forward for the technical and economic strength of automobile production enterprises, which restricts the wide application of laser welding technology in China. At present, its application in automobile body-in-white manufacturing in China is still limited.

Precautions for laser welding:

1. During operation, in case of emergency, such as water leakage or abnormal laser sound, you must immediately press the emergency stop button and cut off the power supply quickly.

2. Because the laser system adopts water cooling mode and the laser power supply adopts air cooling mode, the external circulating water switch of laser welding must be turned on before operation. If the cooling system fails, it is forbidden to start work.

3. When working, it is forbidden to touch all circuit components in the machine. When the laser welding machine is working, the circuit is in a state of high voltage and strong current, and untrained personnel are prohibited from operating the machine.

4. It is forbidden to use the eye scanning laser directly when the laser is working, so as not to hurt the eyes. When the laser is working, it is forbidden to use external equipment to reflect the laser.

5. Do not disassemble any parts of the machine at will, do not weld with the safety door of the machine open, and do not aim the laser head at the equipment parts.

6. Don't put inflammable and explosive articles in the laser light path or where the laser beam can shine, so as not to cause fire and explosion.