Advantages And Challenges Of Laser Welding

What are the advantages of laser welding compared to traditional welding methods? What difficulties will be encountered during laser welding, and how to solve these difficulties? In what application fields is laser welding commonly used? Jinmi Laser will introduce from the following three aspects.

Advantages of laser welding

Compared with traditional welding methods, laser welding has the following advantages:

1. Fast speed, large depth, and small deformation. Laser welding has high energy density, fast heating and cooling speed, small heat-affected zone, small welding stress and deformation. Laser welding can achieve high aspect ratio welds, up to 10:1.

2. Non-contact processing and high flexibility. Laser welding does not require contact with the weldment, nor does it require electrodes or filler materials, which can reduce pollution and loss. Laser welding can be transmitted and transformed through optical elements, and is easy to cooperate with robots to achieve automation and multi-station processing. Laser welding can also be carried out at room temperature or special conditions, which is suitable for welding inaccessible parts or refractory materials.

3. High quality and good performance. Laser welding can reduce defects such as pores and cracks and improve the density and strength of welds due to its low heat input and fast cooling rate. Laser welding can also achieve the connection of different metals or dissimilar materials, improve the organization and performance.

4. Green and environmentally friendly, safe and pollution-free. Laser welding does not produce harmful gases or noise, is not disturbed by electric or magnetic fields, and is harmless to the human body and the environment.

Difficulties and solutions in laser welding

Although laser welding has many advantages, there are still some problems in welding:

1. Welding spatter: refers to the appearance of many metal particles on the surface of the material after welding is completed, which are attached to the surface of the material. This will affect the surface quality of the weld and will also pollute and damage the lens. The reason for the spatter may be that the surface of the material is not clean, there are oil stains or pollutants, or the evaporation of the galvanized layer.

The solution is to clean the surface of the material before welding, appropriately reduce the welding energy, and reduce spatter.

2. Cracks: refers to thermal cracks caused by continuous laser welding, such as crystal cracks, liquefaction cracks, etc. The main reason for the cracks is that the shrinkage force is too large before the weld is completely solidified.

The solution is to use measures such as wire filling and preheating to reduce or eliminate cracks.

3. Porosity: refers to the appearance of pores on the surface of the weld. The reason for the pores may be that the laser welding molten pool is deep and narrow, the cooling speed is very fast, and the gas generated in the liquid molten pool has no time to overflow; or the weld surface is not cleaned, or the zinc vapor of the galvanized sheet evaporates.

The solution is to clean the weld surface, improve the volatilization of zinc when heated, and adjust the blowing direction.