Ultra-precision milling with multiple diamond tools

• Applicant: Professor Dr.-Ing. Ekkard Brinksmeier
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 211652309

Ultra-precision milling with multiple diamond tools requires the possibility of a defined tool adjustment for aligning all tools engaged in the cutting process to a common radius.In this subproject of the research unit FOR1845 Ultra-precision high performance cutting, it was shown that a thermo-mechanical actuator can be brought to a state of defined thermal elongation that allows for a precise displacement of a diamond tool across several micrometers with a precision in the nanometer range. Thus, the concept was transferred to a prototype diamond tool holder that will be able to perform basic fly-cutting operations at the end of the first funding phase.The second funding phase focusses on the application of this prototype tool holder under real cutting conditions. The overarching goal will be the systematic and methodological determination of the systems boundary conditions in the context of generating optical functional surfaces with multiple cutting tools.The first step will be the identification of the methodology for measuring the radial displacement of the diamond tools. This is required for assessing the actual condition of the tool holder prior to cutting and to generate the required set values for the actuator. Subsequently, the tool holder will be applied in ultra-precision milling experiments, in order to obtain a feedback from the machining process. This data will be used to verify the theoretical models of the actuator that were generated in the first funding phase and to assess the performance of the actuator under realistic cutting conditions.As the defined displacement of the cutting edges in diamond machining offers new possibilities for process control, specific aspects will be examined in the proposed funding phase as well. This includes the applicability of a tool displacement in arbitrary directions by asymmetric heating of the actuator as well as using this technique for ultra-precision balancing purposes. At the end of the second funding phase, the thermo-mechanical actuator, among other components that are developed within the FOR1845, will be integrated into a demonstration platform and evaluated for their combined performance. This will be done by conducting ultra-precision milling operations including multiple diamond tools, high spindle speed and feed velocity as well as model-based compensation strategies in the control system and comparing them with conventional ultra-precision milling processes.

• DFG Programme: Research Units
• Subproject of: FOR 1845: Ultra-Precision High Performance Cutting (UP-HPC)
• Co-Investigator: Dr.-Ing. Oltmann Riemer