Effect of recycling on the mechanical properties and formability of sheet metal

This technical note analyses the effect of recycling on the mechanical and forming behaviour of two aluminium alloys (5xxx and 6xxx series) and a low-carbon high-formability steel grade, three of the most widely used sheet metal products in various industries, such as automotive and electronics appliances. Recycled and primary metal sheets were subjected to standardized uniaxial tensile tests and formability tests to assess their mechanical properties and forming limits under different strain paths (uniaxial tension, plane strain and equi-biaxial stretching). The results show that the presence of impurities derived from the recycling may affect material quality in terms of ductility and formability. However, it is shown that recycled materials can exhibit similar performance to that of non-recycled metals with adequate process control. The present paper contributes to a better understanding of the limitations of scrap-based sustainable aluminium and steel alloys, which is essential to promote their widespread adoption in mass-market applications.