Automating and Digitizing Laser Welding Processes

© Fraunhofer IPA / Rainer Bez

Laser welding as a joining technique for the digital production process

The process excels with high speeds and dimensional accuracy up to ± 0.01 mm. Due to the short thermal load, laser welding also protects materials and prevents distortion. Energy is emitted by the laser with pinpoint accuracy over a very short period of time. If the process is supplemented by scanner optics and a fiber laser is used, complex 3D geometries can be processed without having to move the workpiece underneath. Apart from saving time, this also does away with the need for tools to move and position the workpiece. During the process, the exhaust air is purified it almost completely by an exhaust air cleaning system.

With a view to ensuring economical use, the handling techniques for feeding and removing the parts to be welded are currently being optimized. For the purpose of quality assurance, imaging technologies synchronized by a cloud are implemented. However, as digitization advances, there is an increasing demand for the complete acquisition of all process and quality data.

The challenge is first of all to make the device suitable for digital manufacturing applications. Sensors determine the quality of the starting position of the workpieces and a thermal imaging camera detects the temperature distribution. An OPC UA server transmits the process data from the laser cell to a higher-level cloud in real time . This allows the process to be monitored in detail and the laser parameters to be dynamically adjusted via an additional interface. The stored data can also be used later on for quality assessment and for adapting the process parameters for subsequent process steps. The aim is to automate the process in such a way that the entire welding process is self-controlled and self-optimized.

Our services include assessing not only the economic efficiency of laser welding processes but also their technical feasibility for use in production chains. In the course of the assessment, we examine the handling processes, the degree of automation and the basic applicability of the process. By conducting parameter studies, whereby all parameters are recorded and stored, predictions can be made about the expected quality of the process.