The Welding of thin sheet metal

Metalworking necessarily involves considering the nature of the basic elements to be assembled. Welding is a highly technical process that leaves no place for approximation. The point to understand the welding on thin sheet.

Particularity of the fine sheet metal work

The laminated metal in thin sheets, that is less than 1 mm, allows the manufacture of small specific parts, per unit or in small series, which can be found in the automotive, aeronautical, food and pharmaceutical industries, as well as in urban furniture and household appliances. It comes into play to create small structures of more or less complex shapes, in tube or profile, in steel, aluminum, stainless steel or other alloys.

It is therefore a high precision sheet metal work. It presents itself in a completely different light to the work on large parts that could be found, for example, in steel frame. The particularity of thin sheet welding is thus to succeed in assembling thin or extra-thin elements in an efficient way, while limiting unwanted drillings, potentially important deformations, tensions and complex adjustments. Obviously, industrial sheet metal work and thin sheet metal assembly require absolutely essential equipment, technical skills and dexterity.

An evolution of the market which implies technical solutions

To meet safety or performance expectations, the market trend is to produce pre-coated sheets, modified by electroplating, chemical treatment or organic coating. This raises several fundamental questions, such as the early melting point of one element compared to another, or the mechanical strength of the weld once it is put into service, or finally the release of welding fumes to be evacuated during operations.

So many technical points that our subsidiary Jacques Soudure, specialist in fine sheet metal work, solves. With strong expertise in precision sheet metal work from 0.3 to 10 mm, and unique know-how in aluminum, steel and stainless steel, it is also equipped with a technological park that benefits from the best innovations. It is certified according to the EN 9100 standard, and its achievements make it the number one supplier to the aeronautical industry.

Welding processes for thin sheet metal

When welding thin sheets, the challenge is to generate the minimum amount of heat, and therefore to limit the energy applied to the part during welding, in order to avoid holes and deformations. The handling of the equipment – especially an electric arc – must therefore be particularly well thought out, otherwise the temperature of the basic elements may rise too high.

Also, differences in chemical composition influence thermophysical properties and electrical conductivity. The realization of welds on thin sheets requires a perfect mastery of these components and a constantly renewed specialized expertise.

By the different types of welding, several of them are commonly accepted as having the best performance: TIG welding, MIG-MAG welding, plasma welding, laser. They have in common that they can weld different materials, such as stainless steel, steel, aluminum. Robotics not only optimizes their intrinsic qualities, but also limits their disadvantages during welding.

What makes the difference between the processes for precision sheet metal work? The nature of the elements to be assembled, their destination, the will to opt more for the aesthetics or the productivity.

Welding processes for thin sheet metal

Precision and aesthetics with TIG:

TIG is an electric arc welding process that uses a tungsten electrode, a neutral gas to protect the molten pool, and a rod to add metal. It creates the simultaneous fusion of the filler metal and the areas to be joined.

This process allows the assembly of homogeneous and heterogeneous materials, a mix that allows it to respond to many cases. It benefits greatly from automation, which reinforces its original qualities of precision. It is perfectly adequate when looking for a high quality on the finished result and on its aesthetics, because it gives high-performance and almost invisible fine sheet metal welds.

The ideal MIG-MAG for productivity

MIG and MAG welding are similar to TIG, but instead of a tungsten electrode, a coil of wire is unwound as the connection is made. The nuance between the two is mainly due to the gas that protects the melting bath and the nature of the metal worked: the MIG process (Metal Inert Gas) primarily concerns aluminum and its alloys, while MAG (Metal Activ Gas) is suitable for steel and stainless steel. Fully automated, they allow a high yield and a continuous welding of thin sheets.

Plasma for extreme thinness

Plasma welding is in a way the improved version of TIG. The plasma electric arc brings a considerable quantity of energy on a limited surface and allows to act with a notable speed. Compatible with copper, steel, aluminum and other metals as long as they are conductive, this process performs the welding of thin sheet metal down to 50 microns.

The laser, a concentrate of heat

Laser welding of thin sheets concentrates all the energy on the joining point, which can be as small as a few millimeters in diameter. The action is thus fast, with a cooling that is just as fast. The deformations are therefore almost null, very mastered and the welds have a very clean appearance. Remotely controlled by a digital solution, it is also able to reach places that are otherwise inaccessible.