Recycling of metal chips by sintering and forging

• Applicant: Professor Dr.-Ing. Bernd-Arno Behrens
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2012 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 215349600

Each year about 650,000 tons of recycled aluminum (secondary aluminum) are returned to the product lifecycle in Germany. However, the irrevocable loss of the raw material, due to an improper melting, is considerable. Already a fictional aluminum chip share of only 10% of the total volume of the secondary aluminum production will lead to a potential component volume of 65,000 tons for direct forging components.This proposal is addressed to build structural components made of aluminum chips by a new direct recycling process. Based on the results of the first funding period a new forging stage has to be developed for implementing high forming degrees in pressed chips by multiple multi-axial-forging (MAF) in a closed die. Thus, pores and outbreaks can be avoided by back pressure. Monitoring the forming parameters and implementing a process-integrated heat treatment should avoid undesired grain growth in each iteration of MAF; so that mechanical properties can be optimized and process efficiency can be increased. If a sufficient bond has been reached a typical aluminum wrought part will be manufactured in the subsequent finishing stage.This issue has not yet been studied and thus distinguishes itself sufficiently from existing SPD process, or the continuous extrusion of aluminum chips. Another differentiator to existing studies is the realization of high deformation rates. This can further on prevent recrystallization processes which lead to an undesired grain growth.

• DFG Programme: Research Grants