Laser welding is popular because of its fast speed, flexibility, high weld quality, simple operation, and low operating cost, and its applications are becoming wider and wider. However, when welding certain materials or affected by other factors, it is easy to cause cracks.

Cracks occur during laser welding. This is a problem that many people do not want to see but have to face. What's the problem? Is the laser welding process inadequate, or is the laser welding technology immature? To solve the confusion, we must first find out the source of the problem. Next, Foshan Fulan Laser will talk about the causes of laser welding cracks and how to reduce or avoid cracks:

1. Material factors: ?

Factors such as material absorptivity, reflectivity, thermal conductivity, uniformity, etc. may cause cracks during welding. Because the compatibility of laser beam and material absorption depends on some important properties of the material. For example, when aluminum alloy materials are welded, the distribution of alloying elements is not uniform, or the content of impurities inside is different, it is prone to blast holes, undercuts, dents, and cracks.

Ways to reduce or avoid: One is to improve and improve the laser welding process. Different products and different materials have different characteristics. We need to adjust the parameters of the laser welding machine to suit the welding of this product. Thereby reducing the occurrence of cracks.

The second is the filling material: wire filling, which is a commonly used method to eliminate thermal cracks, which can effectively prevent the occurrence of thermal cracks and improve the strength of the joint.

2. Stress factors:

The characteristics of rapid heating and rapid cooling of the laser welding process put the entire joint in a complex stress state, which constitutes a joint crack.

Reduction or avoidance method: According to the nature of cracks, some materials will generate stress during the cooling process of pulse laser welding, which will lead to the generation of cold cracks. Therefore, to reduce the occurrence of cracks, it is necessary to improve the alloy system of the material or adjust the laser welding Related parameters.?

3. Process parameters:

The main parameters of laser welding process include laser output power, welding speed, laser waveform, pulse frequency, defocus amount, pulse width and shielding gas. If the parameters are set incorrectly, cracks will also occur.

Reduction or avoidance method: The operator is required to be proficient in the working principle of the laser welding machine, improve their own laser welding process, and strengthen the laser welding technology.