Laser welding technology, characterized by high efficiency and good flexibility in welding processes, can be utilized in the manufacturing of automobiles for welding car bodies and various automotive components. It can reduce the overall weight of car bodies, enhance the assembly precision of car bodies, and meet the demands for lightweight and improved safety performance in automobile manufacturing. Additionally, it can reduce assembly and stamping costs in automobile manufacturing, and enhance the integration level of car bodies.
Laser welding has revolutionized the automotive industry by allowing for lighter, stronger, and more aesthetically pleasing vehicle structures.
Here are the five major laser welding technologies currently used in automobile manufacturing:
1. Laser Self-Fusion Welding (Deep Penetration Welding)
This is the standard form of laser welding where two pieces of metal are joined using only the laser beam, with no additional filler material. The laser heats the metal to its boiling point, creating a “keyhole” of vapor that allows for deep and narrow welds.
- Best For: “Tailor-welded blanks” (joining steel sheets of different thicknesses), car body assembly, and door frames.
- Key Advantage: It produces very thin, clean weld seams with minimal heat distortion. However, it requires extremely precise fit-up (zero gap) between parts because there is no filler to bridge gaps.
2. Laser Wire Filling Welding
This technique feeds a metal wire into the weld pool while the laser melts the base material.
It is similar to standard welding but uses the precision of a laser.
- Best For: Aluminum alloy parts and body structural components where the fit-up isn’t perfect.
- Key Advantage: The filler wire helps bridge gaps that are too wide for self-fusion welding. It also allows engineers to change the chemical composition of the weld (by choosing a specific wire) to make it stronger or more ductile than the base metal.
3. Laser Brazing
Technically different from “welding,” laser brazing does not melt the car body panels themselves. Instead, the laser melts a copper-based filler wire (brazing rod), which flows between the two panels like a glue to bond them.
- Best For: Roof-to-sidewall connections and trunk lids.
- Key Advantage: Aesthetic perfection. It creates a smooth, “Class A” surface finish that is often left visible on the finished car (the “invisible joint” look found on luxury vehicles). It eliminates the need for those black rubber molding strips on the roof.
4. Remote Laser Welding (Scanner Welding)
This high-speed technology uses a system of mirrors (galvanometers) to steer the laser beam incredibly fast from a long distance (often 0.5 to 1 meter away), while the robot arm moves continuously over the part.
- Best For: Seats, doors, and complex “Body-in-White” structures with many short welds in different spots.
- Key Advantage: Speed. It eliminates the “non-welding time” caused by the robot repositioning itself. The beam can jump from one weld spot to another in milliseconds, making it 5-10 times faster than traditional spot welding.
5. Laser-Arc Hybrid Welding
This method combines a laser beam and an electric arc (like MIG/MAG welding) in the same welding head. The laser provides deep penetration, while the arc fills the gap and stabilizes the process.
- Best For: Thick plates, chassis components, and axles.
- Key Advantage: It offers the “best of both worlds”—the speed and depth of a laser with the gap-bridging and toughness of arc welding. It is excellent for heavy-duty structural parts where safety and durability are paramount.