Tribosystems for cold forming processes based on volatile lubricants and laser structured surfaces

• Applicants: Professor Dr. Thomas Graf; Professor Dr.-Ing. Mathias Liewald; Professor Dr. Günter Tovar
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing ; Production Automation and Assembly Technology
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282210782

Most metal forming processes use lubricants based on mineral oils as an intermediate medium to reduce friction and wear. However, These lubricants may contain toxic additives and the formed parts need to be cleaned for further process steps which is very time consuming andexpansive. During the first two funding periods an innovative and environment friendly lubrication system for metal forming processes was introduced. Liquid carbon dioxide and gaseous nitrogen are being used as volatile lubricant media. The suitability of this newtribological system for dry metal forming processes was demonstrated by single forming processes. The goal for the third funding period is to demonstrate the usability of this new tribological system for dry metal forming processes with a practical orientation. Therefore we will Show the suitability of the new tribological system for forming processeswithin endurance runs. For this demonstration it is necessary to ensure process stability. For the purpose of process stability it is essential to optimize the new tribological system. A deeper understanding of the friction and wear mechanisms within thiscomplex tribological system serves as a basis for optimization. Furthermore it is important to understand the physical mechanisms during the escape of the volatile lubricant media during the forming process. Micro drillings of highest precision and quality are necessaryto ensure process stability. Precise drillings without any Burr guarantee a stable and reproducible flow of the volatile lubricant media and avoid any additional friction. The generation of Surface structures that ensure a homogeneous distribution of the volatilelubrication media are an additional step towards an increased process stability. The practical relevance of this new tribological system will be shown by forming additional metal sheet materials with increased adhesion tendency. In this case the tribological system needs to beadapted to ensure the separation of the basic body and the antibody and to reduce and adapt friction during the forming process. Within the different institutes the following steps will be realized: 1) advancement in understanding the tribological system taking anothermetal sheet material into account. 2) Optimization of the current tribological system. 3) Investigation and extension of process stability within endurance runs of forming processes with a locally adapted tribological system.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1676: Dry Metal Forming - Sustainable Production through Dry Processing in Metal Forming
• Co-Investigator: Dr. Jakob Barz