Tailor made properties in steel and aluminium by local heat treatment for optimized joining (TAMAPRO)

Purpose and goal:

The pre-study TAMAPRO had the goal to show feasabilty of quick local heat treatment by laser or induction heating to improve the mechanical joining of cast aluminium and ultra-high strength steel. The project delivered an in-depth analysis of the correlation between the investigated heat treatment processes, resulting microstructure, joining results and the joint properties when joining with self-pierce riveting (SPR) and flow drill fastening (FDF).

It could be shown that both processes are able to improve the joining results and joint properties significantly. Expected results and effects:

Laser- and induction heating can be applied to increase ductility in cast aluminium materials to a degree that self-pierce riveting is possible even within recycled aluminium without the often seen extensive cracking in the material. It can also be used to join ultra-high-strength steels (UHSS) like boron steel with FDF that is normally only possible by drilling pre-holes into the material.

The results can now be used to drive the technology development towards industrialization and will allow the increased usage of cast aluminium and UHSS in car bodies and other products. Approach and implementation:

The project runtime was planned for 10 months. Due to the covid pandemic some delays resulted within the project which led to an extenstion of the project runtime by 2 month. The project was structured into 4 work packages which were conducted in close collaboration which led to good project results and good achievement of the set objectives.