OPTIMIST-RSW - Optimised aluminium-steel joining by novel approach for intermetallic layer in resistance spot welding

Purpose and goal

The project aims to develop a method for creating robust fixation joints between advanced material combinations, for example secondary aluminium and steel, by spot welding (RSW). The focus is to optimise the geometry of the intermetallic compound (IMC) formed during welding, to achieve sufficient strength without increasing the crack susceptibility. The goal is to demonstrate the methodology for optimising the geometry of the IMC layer as a robust fixation solution in hybrid RSW adhesive joints.

Expected effects and result

The project will contribute to greater flexibility in material selection by promoting the use of more sustainable material combinations, as well as enabling more circular design solutions by enabling use of existing, well-known and sustainable production systems where the primary joining method is resistance spot welding. New knowledge will also be generated related to the use of non-destructive testing to connect the IMC layer geometry and the impact on the structural integrity of the joint.

Planned approach and implementation

OPTIMIST focuses on optimising the RSW process, and using CT scanning as a non-destructive method for increased understanding, according to the following project outline: WP1 – Material delivery, setting of requirements and selection of demonstrator WP2 – Weld process development WP3 – Mechanical and metallographic evaluation WP4 – Assessment of joint characteristics in relation to requirement specifications WP5 – Demonstrator WP6 – Project management and dissemination of results