Laser welding is an efficient and precise welding method that uses a high-energy density laser beam as a heat source, but this process requires consistency between the laser beam and the size of the welding seam. Relatively speaking, gas metal arc and series welding are better at handling situations where gap sizes are inconsistent. Therefore, some car manufacturers combine laser welding and gas welding to achieve ideal welding results.

Currently, car buyers are placing increasing demands on the quality and performance of their products. To meet the needs of customers, continuous process innovation is necessary.

The same applies to laser welding processes. Automobile manufacturers hope to adopt processes with faster welding speed and shorter production cycles while ensuring product quality and maintaining certain welding flexibility for different gap sizes. Nowadays, traditional laser welding processes can no longer meet these two production requirements.

However, the successful application of laser brazing, a hybrid welding process that combines laser welding with gas shielded arc welding (GMAW), has solved this welding problem. We know that laser welding produces a very narrow molten pool. The size of the molten pool is proportional to the welding depth and weld width, thereby achieving very high welding speed. However, due to the very small focal diameter of the laser beam, laser welding cannot easily cope with situations where the seam width differs significantly from the laser beam diameter. The energy density of gas shielded arc welding (GMAW) is low, which can form large light spots on the surface of materials, and can produce good welding effects for various seam widths.

Now, this hybrid welding process has been tested on some automotive production lines, and the welding effect is very ideal.

Introduction to Laser Hybrid Welding Technology

Unlike assembly line operations with a certain process sequence, hybrid welding involves simultaneously performing two welding methods in the same process. Different welding strength and characteristics can be adjusted by selecting different arc welding and laser welding process parameters. Compared with a single process, the welding depth and welding speed of the combined process have been significantly improved. The metal sublimates in the welding cavity and reacts with the arc plasma. The absorption of Nd: YAG laser radiation in plasma is negligible. By adjusting the power ratio of laser welding and arc welding, the welding speed and flexibility can be designed to cope with different weld widths, so as to produce different welding effects.

Compared with pure laser welding technology, laser hybrid welding technology has the following advantages: it has high gap bridging ability, better instantaneous penetration width and depth, wider application range, and better welding toughness. Compared with the single gas arc welding process (GMAW), laser hybrid welding shows higher welding speed, deeper penetration at high speed, less heat input, higher welding strength and narrower weld formed.

Compared with the traditional laser welding, the hybrid laser welding process combining laser welding and gas arc welding can form a larger weld pool. Therefore, the laser hybrid welding process can meet the welding requirements of wide weld components that are not applicable to conventional laser technology.

Application of Laser Welding in the Automotive Industry

Laser hybrid welding can provide high welding speed and strong penetration, but the required heat input is significantly reduced. Compared with conventional wire welding processes, the welding speed of laser hybrid welding has increased by approximately 30%. The reason why laser hybrid welding technology can balance deep penetration and good welding performance is that the laser beam has high energy density and the welding wire can fully fill the cross-section of the weld. A few years ago, this welding process was already promoted and used among frontline automotive suppliers.

The good application of laser hybrid welding technology in side panel welding has greatly improved the automation of welding. Compared with traditional gas arc welding

• The laser hybrid welding production line can save nearly half of the production space;
• Reduce welding wire consumption by 80%;
• Increase welding speed by 30%;
• Compared with the traditional gas arc welding welding process, laser hybrid welding saves nearly 30% of human labor.

Laser composite welding process

When performing laser hybrid welding), two welding arcs are generated in the welding area, the laser beam at the front end is used to weld the bottom, and then the gas arc welding process is used to close the gap and increase the weld thickness.

High flexibility is an important feature of hybrid welding processes. For example, three different output powers can be set based on the desired welding effect. In this way, the operator can design the power output parameters during the hybrid welding process, and refer to the weld geometry to set the welding path and select a reasonable welding speed. The welding depth can be comprehensively adjusted by combining laser power, focal diameter, and welding speed. Additionally, two different types of metal welding wires can be used to achieve better welding results.

About HGTECH: HGTECH is the pioneer and leader of laser industrial application in China, and the authoritative provider of global laser processing solutions. We have comprehensively arranged laser intelligent machine, measurement and automation production lines, and smart factory construction to provide overall solutions for intelligent manufacturing.