Aluminum alloy laser welding three difficult solutions

Laser technology has been paid more attention to in the field of aluminum alloy welding because of its characteristics of low welding heat input, little influence of welding heat area and low deformation.But on the other hand, there are three difficulties in laser welding of aluminum alloy due to its own defects. So how to solve subtly?

Welding difficulty 1: low laser absorption rate of materials;

Solution:

1, take the appropriate surface pretreatment process. Such as sandpaper grinding, surface chemical etching, surface plating and other pretreatment measures. Increase the laser absorption rate of materials.

2, reduce spot size, increase laser power density.

3, change the welding structure, so that the laser beam in the gap to form multiple reflection. Easy aluminum alloy welding

Welding difficulty two: easy to produce pores and thermal cracks

Solution:

1. After many welding tests and studies, it is found that adjusting the laser power waveform in the welding process can reduce the unstable collapse of porosity, changing the Angle of laser beam irradiation and applying magnetic field in welding can reduce the porosity generated during welding.

2, in the use of YAG laser, the pulse waveform can be adjusted to control the heat input, to reduce the crystal crack

Welding difficulty three: during the welding process, the mechanical properties of the welded joints decrease;

Solution:

The mechanical properties of the welded joint are caused by the instability of the porosity in aluminum alloy welding. Aluminum alloy mainly includes Zn, Mg, Lv three elements. During welding, the boiling point of aluminum is higher than that of the other two elements. Therefore, some low boiling point alloy elements can be added in the aluminum alloy welding, which is conducive to the formation of small holes and welding firmness.

Conclusion:

The high efficiency of aluminum alloy laser welding makes people look forward to its development prospect very much. Therefore, some researchers have continuously developed new technologies such as laser-arc coincidence process and dual-focus technology to improve the stability of welding process and improve the quality of welding seam