Coupling of experimental and numerical methods for multiscale analysis and modelling of coolant influences and mechanism in cutting processes (KExNuMe-KSS)

• Applicants: Professor Dr.-Ing. Berend Denkena; Professor Dr.-Ing. Gerhard Poll
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 439904924

The efficient use of cooling lubricants requires a deeper understanding of the underlying mechanisms with regard to chip removal, cooling and influencing friction conditions. In addition, a reduction in the cooling lubricant volume flow shows a high potential for saving energy and resources. However, the targeted design of the lubricoolant strategy requires an understanding of the fundamental mechanisms of action, which are still unclear. One approach to designing the cooling lubricant strategy is the use of simulations. However, simulative approaches only take tribochemical and thermal effects into account to a limited extent. This is due, for example, to a lack of knowledge of the influence of the cooling lubricant on the tribological system along the cutting wedge. As a result, there are no simulation approaches that can be used for targeted process design considering an efficient cooling lubricant strategy. In order to create such approaches, experimental and simulative foundations were created in the previous phases of the priority program by the proposed sub-project. This includes the friction and lubrication conditions at the secondary shear zone of the rake face as well as macroscopic effects of the cooling lubricant supply on tool load and chip formation. For the design of cooling lubricant strategies, however, this knowledge must be expanded to include the thermal effects of cooling and lubrication, in particular to deepen the understanding of the influence of tribological mechanisms. The originality of the project proposed here lies in the fact that numerical methods from the field of tribology are extended to include tribochemical processes specific to machining, taking cooling lubricants into account. The main objective of the project is therefore to understand the effect of cooling lubricant on the entire tribological system on the cutting wedge and to derive an energy-efficient cooling lubricant strategy for optimizing tools and processes. In particular, the influence of thermal load and relative speed on the tribology of the cutting wedge is being investigated. At the same time, the focus is on expanding knowledge with regard to static friction as a result of high normal stresses and tribology at the flank face contact. In conjunction with tribochemical analyses and analogy studies, a simulation approach is ultimately available that enables results-oriented production optimization through complete modelling of the tribological system on the cutting wedge. This is used to achieve an increase in efficiency through adapted cooling lubricant supply conditions.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2231: Efficient cooling, lubrication and transportation – coupled mechanical and fluid-dynamical simulation methods for efficient production processes (FLUSIMPRO)
• Co-Investigator: Dr.-Ing. Christian Pape