Influence of machining thin lightweight construction node components from aluminum alloys on residual stress and micro hardness in the outer surface zone

摘要

The described research work deals with the manufacturing of connection elements (Figure 1) made of Aluminum for the lightweight frame structure for the production of an electric car. The connection elements form the joining zones for tubular structures with a diameter of 40 mm. Joining processes for such as electromagnetic forming, welding or screwing are used. For these nodal structures to be light, but also adequate for the respective joining process, it is necessary to determine experimentally the minimum wall thickness of the nodal elements. For a wcldment, the connection elements should have a similar wall thickness to the other part, while for electro-magnetic forming they should possess the highest possible rigidity. Furthermore it is necessary to identify the hardness changes and residual stresses in the outer surface layer brought about by the milling process as they influence the joining process [1]. For this reason these parameters are considered as boundary conditions for the determination of the minimum wall thickness.