Aluminum and aluminum alloys are widely used in construction, transportation, automotive, electronics and aerospace, as well as in various welded structural products due to their light weight, high strength and corrosion resistance. With the development of technology, the welding process of aluminum alloys has been improved, and the use of aluminum alloys instead of steel plates can reduce the weight of the structure50%above。

★SUMMUSXinhe Laser, characteristic water-cooled board products ★

In the daily welding process, due to the special properties of aluminum, laser welding of aluminum and aluminum alloys will be difficult to control the laser focus and molten pool. If the process parameters are set improperly or the welding personnel lack rich experience, problems such as pores, cracking deformation, weld blackening and unblending of undercuts may occur, which seriously affect the welding quality and performance.

SUMMUS laser has the characteristics of high power heat source concentration, small heat affected zone, small deformation, energy saving and consumption reduction, and is the best choice for welding aluminum materials.

Problem 1: Stomata.

The main problems encountered when using laser welding aluminum are pores. During the welding process, the laser beam causes the metal in the molten pool to fluctuate. When the gas trapped in the metal expands and overflows, pores will appear. In addition, the aluminum oxide film will hinder the bonding between the metals, absorb moisture and easily produce impurities, which will promote the formation of pores. The generation of pores can lead to weaker weld strength, reduced corrosion resistance, and unsightly welds.

SUMMI Solution:

1. Adjust the appropriate laser power to ensure uniform heat input.

2. When welding thin plates, it is recommended to increase the speed to reduce the time for gas to expand in the metal; when welding thick plates, under the condition of preheating the material, the welding speed can be reduced to ensure the weld performance.

3. Perform chemical or mechanical cleaning of the weld surface to reduce the impact of impurities on the welding quality.

Problem 2: Thermal cracking.

Due to the high temperature generated during the welding process, aluminum can expand and contract rapidly, and stress points can be generated. If the solidification interval of the weld is too short and the stress points are not released, they can cause aluminum cracking and hot cracking. In addition, when the weld protection effect is not good, it is also prone to oxidation and hot cracking.

SUMMI Solution:
In order to avoid this situation, we need to control the heat during the welding process, fully preheat the weldment before welding, and adjust the protective gas.

Problem 3: The weld is black.

The blackening of laser welding aluminum is mainly caused by insufficient laser power, the defocusing amount is not adjusted to an appropriate value, or the laser lens is damaged. In this case, the energy of the laser fails to reach the melting threshold of the oxide layer on the surface of the aluminum, which makes the aluminum mix with space and impurities, resulting in the blackening of the welding part.

SUMMI Solution:

In order to better achieve the quality and aesthetics of welding, during the aluminum welding process, SUMMUS Xinhe laser first selects the appropriate power, sets the correct defocus amount, and secondly checks whether the protective lens is damaged.

Problem 4: The undercut is not fused

When laser welding aluminum, the weld bead is discontinuous, rough and uneven, and the main reasons are too large welding assembly gap, laser light spot offset, insufficient laser power and too large defocusing amount.

SUMMI Solution:

First, we can reduce the root gap of the welded workpiece; secondly, adjust the focus of the laser beam to determine the correct light spot position; in addition, we can also increase the laser power and adjust the positive focus position of the defocusing amount to ensure the welding quality after aluminum melting.

Due to the particularity of aluminum, other problems are also encountered in the process of laser welding. Before welding aluminum and aluminum alloys, we must not only consider the stability of welding quality, but also the appearance effect of welding. With the improvement of SUMMUS laser technology and aluminum manufacturing technology, the process of laser welding aluminum has also been greatly improved, providing a solid foundation for creating lightweight metal structural parts in automotive, aerospace and other fields.