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Is laser welding so magical?

The concept of laser welding, most Chinese consumers know from Volkswagen publicity. In the mouth of the salesman, it is the main reason for the strong and durable Volkswagen. Many relatives and friends around me also chose Volkswagen because of this safer laser welding. Today we take a look at what is laser welding stuff? In the end there is no publicity so cattle.

At present, the main welding technology in automobile manufacturing is resistance welding and laser welding. There are four main methods of resistance welding, namely spot welding, seam welding, projection welding and butt welding.

What is resistance welding?

Resistance welding is the combination of the workpiece through the electrode pressure, the use of current through the contact surface of the joint and the resistance heat generated by the adjacent area welding method.

What is laser welding?

Laser was one of the greatest inventions of the last century, and the world's first laser came out in 1960. Laser welding heats the surface of the workpiece by laser radiation. The surface heat diffuses to the inside through heat conduction. The workpiece melts by controlling the width, energy, peak power and repetition frequency of the laser pulse to form a specific molten pool. Therefore, it is often used by automobile manufacturers for welding between the roof and the body, which has the advantages of good appearance, sound insulation and good sealing.

Only the public with laser welding?

When it comes to laser welding, we first think of the public must be, after all, they conducted a lot of marketing. In fact, in many depot, not only the public can know how to play laser welding, such as Mercedes-Benz, BMW, Peugeot, Nissan and other car companies have the use of this technology, the domestic own brand, there are models using laser welding technology.

What are the advantages of laser welding?

Laser welding mainly focus on the heating range and precise control, welding deformation, welding speed and so on. First, laser welding is much faster than resistance spot welding. For example, 6s time, laser welding can weld 1m long weld, and resistance spot welding can only be welded 1 point. Second, the laser welded joints are continuous, naturally not as there is water leakage problems like resistance spot welding joints, so you can dispense with sealant coating process. Finally, the deformation of the laser welding head is small, which helps to reduce the step difference between the metal covers and improve the precision of the vehicle body, meanwhile, it is also beneficial for the splicing of steel plates with different strengths.

Whose strength is higher?

The laser welded joint is a slender, continuous straight line, while the resistance spot welded joint is a row of discrete dots. The laser welded weld metal is obtained by rapid solidification, which is finer and will help to improve the weld The strength of the metal, so the laser weld metal strength than the resistance spot weld metal strength of a little higher.

Is it worth it for laser welding?

Through the above we already know the advantages of laser welding, certainly most consumers will choose laser welding models, after all, safety first! However, laser welding is not amazing technology, after welding parameters to optimize the factory later, although the strength of the resistance spot welding but laser welding, but still higher than the metal base material, the overall welding body is the weakest link in the base material Of the weld heat affected zone. In other words, the metal matrix, especially the HAZ, is the weakest link, so once the body is subjected to a strong external force, the metal matrix is ​destroyed in most cases, not welded joints. It is precisely because of the existence of a short piece of metal base material, making the laser welded body and resistance spot welding body showed almost no difference between the strength of the external.