Why is copper welding so difficult?
To answer this question, one must take a closer look at the properties of pure copper.
What stands out is the high thermal conductivity compared to steel. Depending on the temperature range, it is 5 – 15 times higher, which is also the reason for the more difficult weldability. In addition, the high reflectivity of the copper surface makes beam welding, which also includes laser welding, more difficult.
Thanks to our many years of experience, however, we have succeeded in finding a reproducible solution for the beam welding of copper. As a result, we are able to safely apply laser welding up to a material thickness of 0.5 mm. Here we produce joints that meet all tests 100%, especially in electrical conductivity and strength of the weld.
For greater material thicknesses – up to 5 mm – we reliably use a laser hybrid process.
In beam welding processes, the high reflectance of copper is the main factor. At the moment when laser or electron beams strike the copper, the high reflectance of the copper surface means that only about 5 % of the energy is absorbed by the material.
In conventional welding processes, such as arc welding or gas welding, the high thermal conductivity, coupled with the melting point, poses an enormous physical demand. The component absorbs so much heat when welding is attempted that there is a risk that it will warp and dimensional accuracy can no longer be established after welding.
20 years of experience in copper welding have enabled us to develop a process that allows us to weld components up to a welding depth of 0.5 mm using a pure Nd:YAG laser with a wavelength of 1064 µm.
From a welding depth of 0.5 mm to 5 mm, we weld these components reliably and safely with a laser hybrid system.
Especially in the field of e-mobility and the energy industry, we can achieve great successes with this.
We would be happy to advise you!