Friction-Induced Recycled Aluminium Semi-finished Products in Thermo-mechanical Joining Technology

Due to current global challenges regarding energy security as well as climate change the importance of preserving the nature and all available resources is steadily increasing. In order to achieve the energy-saving and climate targets, it is not only necessary to develop new processes and processing possibilities, but also to optimise known process chains with regard to energy and resource efficiency in the area of production technology. Here, the recycling of supposed production waste represents an opportunity to save energy. In addition to the conventional and smelting metallurgical recycling process, extensive research activities have therefore been carried out for alternative solid-state recycling processes. One example is the friction-induced recycling process, which has been used in past studies to demonstrate the energy- and resource-efficient production of semi-finished products from aluminium scrap such as chips. In addition, properties like chemical composition and strength can be adjusted locally and in terms of processing time. This can be used to improve the versatility of further processing steps. In this paper, starting from the successful forming of auxiliary joining elements from the recycled semi finished product, a comparison is aimed with auxiliary joining elements made from conventionell produced semi finished products. The evaluation of the mechanical properties of the joint connections produced in a second step shows that recycled semi-finished products exhibit comparable properties. This implies the production-technical suitability of secondary metals and opens up broad potentials for improving the versatility of joining processes through property grading in solid-state recycling processes.