KNIW - Concept study for new innovative RSW

Purpose and goal

The pre-study aimed to evaluate if modified electrode geometries can lead to an increased weldability of complex material combinations. This objective was reached. The project results show that electrode caps with a controlled cavity in the contact surface leads to an increased weld quality and process robustness. The new geometries enable use of new more advanced and complex material combinations. This will in turn enable lighter components and products with maintained, or even increased, quality and crash-safety.Further development is required for industrial implementation.

Expected results and effects

The newly developed technique is considered to have good possibilities for quick industrial implementation since the results show that the new electrode geometries enable welding of complex material combinations and since the geometries are designed in order to fit in existing industrial equipment. However, further development is needed in order to enable full industrial use of the technique. Long term effects after a continuation project is to decrease weight of components and products, and enable increased use of the cost efficient and environmental friendly RSW-process.

Planned approach and implementation

A number of new geometries were designed in the initial phase of the project. These geometries were evaluated by weldability tests on a number of material combinations which are considered to be difficult to weld with standard equipment. The results from the tests were analyzed in order to gain knowledge regarding how the geometrical modifications affect the weldability. This knowledge were used to further improve the designs. FE-simulations were also performed. However, not with required accuracy. Some mechanical testing was performed on welded joints with good results.