Direct recycling of aluminium: Chip Extrusion

Recycling of aluminum scrap reduces the energy required for production by up to 95 % compared to primary aluminium production. However, the conventional recycling routes of aluminum are accompanied by a loss of material after remelting. In particular, the remelting of chips leads to material losses of up to 17.5 %. In addition, direct recycling by chip extrusion, without remelting, showed an energy saving of approx. 50 %.

Aluminium chips or shredded aluminium scrap is compacted to cylindrical billet which are heated and loaded into the hot extrusion press. The appearance of the chip-based profiles are similar to conventional profiles and the mechanical properties are 95 % of the cast-based profiles. Together with the french institutes ICMPE, IRCP and GeM, the behaviour of oxides in the extrusion process and the influence on the properties is investigated.

Motivated by the high energy saving potential, serveral cases studies with with national and international companies have been sucessfully conducted and the implementation of chip extrusion is analyzed.

Lilensten, L., Laurent-Brocq, M., Duchaussoy, A., Adrien, J., Maire, E., Duchateau, T., Schulze, A., Tekkaya, A. E., 2025. Analysis of the mechanical damage of a solid-state recycled aluminium alloy under tensile loading. Materials Science and Engineering: A, 944, 148896. https://doi.org/10.1016/J.MSEA.2025.148896

Corre, T., Perrin, J., Gebhard, J., Duchateau, T., Lilensten, L., Laurent-Brocq, M., Tekkaya, A. E., Huneau, B., 2024. Tensile and shear behavior of recycled AA 6060 aluminium chips by direct hot extrusion. Materials Science and Technology. https://doi.org/10.1177/02670836241287768

Selvaggio, A., Tekkaya, A. E., 2023. Identification of Factors Influencing the Quality of Extruded Profiles Using Aluminum Recyclate-Based Billets. Manufacturing Letters, 35, 1326–1335. https://doi.org/10.1016/j.mfglet.2023.08.076

Laurent-Brocq, M., Lilensten, L., Pinot, C., Schulze, A., Duchaussoy, A., Bourgon, J., Leroy, E., Tekkaya, A. E., 2023. Solid state recycling of aluminium chips: Multi-technique characterization and analysis of oxidation. Materialia, 31, 101864. https://doi.org/10.1016/J.MTLA.2023.101864

Schulze, A., Hering, O., Tekkaya, A. E., 2022. Production and Subsequent Forming of Chip-Based Aluminium Sheets Without Remelting. International Journal of Precision Engineering and Manufacturing-Green Technology, 9(4), 1035–1048. https://doi.org/10.1007/s40684-021-00395-8