Laserline: Welding copper with a diode laser

Research & development of diode laser systems has led pioneering German manufacturer Laserline to introduce a Hybrid system that notably can be used for welding thick copper parts.

Laserline laser systems is well known worldwide, with many installations in a range of industries including on the production line of various Audi models for welding tailgates, doors and roof joints. The systems are favoured due to the high-quality finished product and their use in conjunction with a robot for automated process controls. Welding of aluminium often requires a filler material but can be used on visible surfaces without further processing – a result that has been tested and used by Audi in Germany. In Australia Laserline lasers are used extensively for cladding, repair and refurbishment of worn or damaged parts. A 3D process is also possible to print new parts or add functionality. Recently Laserline has focused on developing a system suitable for welding copper, a key component in many modern technological devices. Copper is one of the most important raw materials for electrical power and signal transmission, and with the growing use of small devices, the demand for good quality welding that provides suitable results was an area where Laserline focused its research & development (R&D). Found in battery cells of mobile devices, in induction coils and in accumulators of electric cars, copper can be found almost everywhere. Building a laser system that would be suitable for welding copper in devices led to the introduction of Blue Diode Lasers. Faced with the challenge of copper welding, Laserline analysed the range of copper components, identifying differences from waferthin wires to sheets millimetres thick. For example, to effectively join thin foils required a welding tool that has low impact depths and moderate energy inputs but high intensity to actually fuse the copper. The decision was made to move from an infrared laser to test Laserline’s new LDMblue, designed for industrial purposes with a multi-kilowatt range and a wavelength in the blue spectrum. Its higher absorbtion in most non-ferrous metals leads to spatter free copper welding. However, the LDMblue did not provide a complete solution on its own to also weld thick copper components. Having realised very early that diode lasers offer an economical and compact heat source that can be adapted to many laser material processing applications, Laserline pursued product development to meet the thick copper welding challenge. Clearly, further consideration was required to find a product that would be suitable for all types of copper, from wafer-thin wires to thick sheets. To attain deeper welding seams, a Hybrid concept has been developed that combines the blue diode laser with the traditional infrared laser. The laser beam from each is merged using a special focusing optic. To fuse the workpiece surface, the high absorption rate of the blue diode laser begins the process, with the infrared laser performing the actual deeper keyhole welding process. The advantages of the blue laser guarantees a calm and stable melt pool, significantly reducing spatters. In a welding process that requires a depth up to 3mm, the molten pool provides a finish without visible spatters or pores in the seam. Where lap welding of two copper sheets is required, smooth joining seams can be attained with no impurities observable. While Laserline’s new Hybrid system has already shown it is reliable and suitable for customer usage, the company continues to develop and improve the usability of this new Hybrid system. Its goal is to make welding depths to more than 3mm using this Hybrid approach. This is an exciting field given the move towards battery production and small technological devices that require copper components.

Welding copper with the Hybrid concept, utilising LDMblue and infrared lasers. The Hybrid concept from Laserline, combining a blue diode laser with a traditional infrared laser.

The Laserline copper welding process.

Laserline aims to become a prominent solution provider as the demand for these products grows. Any Australian company intending to grow their market in this new sector with a Laserline blue and/ or Hybrid system can find assistance with Raymax Applications, offering training, advice and ongoing support.

www.raymax.com.au