Defined cutting edge preparation for process optimization in micro milling

• Applicant: Professor Dr.-Ing. Eckart Uhlmann
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering ; Production Automation and Assembly Technology
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 217918378

The micro milling process is characterized by a target geometric complexity, a wide range of materials and a large economic potential. One reason for the failure of micro milling tools is usually the wear of the cutting edges, which occurs as a result of high loads when cutting the material. A defined cutting edge preparation provides an approach to stabilize the cutting edge and to reduce wear. The result is higher tool life and process stability.The aim of the overall project is the improvement of the micro milling process by optimizing the micro milling tools through using the preparation of the cutting tool. In the foreground is the experimental and simulative exploration and definition of the optimal process parameters and processing strategies of the immersed tumbling which is also known as drag finishing in the industry. By wear analysis of respectively prepared and unprepared micro milling tools, basic knowledge about the optimal cutting edge geometry in dependence of the process conditions will be obtained.In the first funding period, a strategy for metrological analysis of micro milling tools was worked out at the beginning. Subsequently, the process parameters in the immersed tumbling were analyzed for the defined cutting edge preparation and a regression model was generated. Furthermore, cutting edge geometries for increased process safety were identified by wear and cutting force analyses and the basics for the creation of a predictive model for the simulation of immersed tumbling were developed.In the second funding period, the prediction model will be completed and a numerical calculation of the geometrical change in the immersed tumbling will be made. Furthermore, various tool coatings will be characterized and the resulting change of the cutting edge geometry by coating will be determined. The objective of this funding period is the exploration and definition of machining strategies for the pre-processing and post-processing of coatings by the immersed tumbling. An optimized coating preparation is to reduce the chipping of the cutting edge and increase the coating adhesion to the cutting edge. The aim of the tool post-processing is the removal of unwanted droplets on the tool surface which occur during coating by arc PVD. Through the wear and cutting force analysis, knowledge about the behavior of generated cutting edge geometries depending on the process conditions will be obtained and finally the experimental results of both funding periods will be used for the definition of optimized pre-processing and post-processing strategies of coatings.

• DFG Programme: Research Grants