ROWELDAL - Robust resistance spot welding for next generation light weight car bodies

Important results from the project

The project has been completed as intended, although the results show that further work needs to be done. Since the project budget was limited only a small optimization work could be done for both the coated caps welding parameters and the laser ablation. The problems with aluminium welding within the automotive industry has been highlighted and described. Two innovative ways of creating a profitable welding scenario for future light-weight vehicles has been studied according to the aim of the project. A full project application is planned and will continue where this pre study ended.

Expected long term effects

The results from the experiments showed potential, although further tests needs to be done. There were indications that the coated caps can decrease the wear of the electrode. However, more experiments needs to be done in order to both reach a desired lifetime of the caps and maintain the weld quality. Also the experiments with the laser ablation indicated that this process can be useful. However, to ensure the quality of the cleaning process a better suited laser source needs to be evaluated.

Approach and implementation

In this project a number of new materials for electrode caps were investigated in order to decrease or even cancel the need for tip dressing. The main idea was to add an inert coated surface between the cap material and the sheets in order to avoid alloying of the caps. Another part of the project was to investigate the possibility to use laser ablation instead of the commonly used dressing with a cutting tool. Implementation of the laser ablation into the automotive industry was thought to both reduce the dressing time and the amount of wasted material.