Laser beam joining of material combinations for automotive applications

An ideal material for automotive applications would combine the following properties: high corrosion resistance, high strength, high stiffness and not at least a low material price, Today a single material is not able to meet all these requirements. Therefore, in the future different materials will be placed where they meet the requirements best. The result of this consideration is a car body with many different alloys and metals, which have to be joined to one another. BIAS is working on the development of laser based joining technologies for different material combinations, especially for thin sheets used in automotive applications. One result of the research is a joining technology for an aluminium-steel-joint. Using a Nd:YAG laser the problem of brittle intermetallic phases between these materials was overcome. Using suitable temperature-time-cycles, elected by a FEM-simulation, the thickness of intermetallic phases was kept below 10 mu m. This technology was also applied to coated steels, which were joined with different aluminium alloys. Further it is demonstrated that titanium alloys, e.g. used for racing cars, can also be joined with aluminium alloys.