The remarkably long electrode life was achieved by polishing the copper electrodes during the brief gap in time between each welded component.
Resistance spot welding is the most widely used process for joining steel sheet in the automotive industry, largely because it is the most cost-effective method for high-volume production and excellent at pulling together components prior to welding. However, a major hurdle preventing the adoption of this joining process for aluminium automotive sheet has been the problem of short electrode life and associated loss of weld quality.
Previous studies have shown that the electrode life can be extended to a few thousand welds by regular tip dressing using a form-cutter, of the type commonly deployed to maintain the electrodes when welding galvanized or high-strength steels. This study has demonstrated the significant additional improvement in electrode life that can be gained by using a system that polishes the electrodes with an abrasive wheel to maintain their domed profile.
This resistance spot welding study has also investigated low-cost methods for detecting electrode damage to determine automatically when to conduct electrode maintenance and when to change the electrodes, which could lengthen the electrode life even further.
Note for Editors
This research was conducted as part of the Premier Automotive Research & Development programme, with funding from Advantage West Midlands and industrial support from Jaguar, Land Rover, Innoval Technology, Novelis, AMDP tip dressing, Aro-Welding, Bosch-Rexroth, Matuschek and Comau Robotics.
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