Methodological Approach for Designing Milling Processes for High Heat Resisting Materials

Recent market studies regarding the air traffic sector exhibit a continuous and fast growth in global scale. For instance, for the number of airplanes in the world fleet a yearly increase of approximately 3.5 percent is expected. This forecast together with the intensifying legal restrictions referring to the amelioration of fuel-efficiency and security of airplanes leads to extensive demands, for example referring to the manufacture of turbine parts out of advanced materials, e.g. nickel-based alloys. Accepted secure-relevant and high loaded turbomachinery parts are blisks (blade integrated disks), impeller and blades. These geometrical and metallurgical high-complex components are designed to withstand extreme thermal and/ or mechanical loads during their later application. However, the sophisticated properties of these materials are attended by severe challenges regarding their machinability, often leading to high tool demand, bad surface qualities, long lead times and resulting long times-to-market for relevant product innovations. Therefore, research activities in cutting of such alloys focus on the one hand on the realization of high stock removal rates in roughing and high surface finishing rates as well as high surface qualities in finishing processes. On the other hand, in order to support a time- and cost-efficient implementation of required product innovations into airplanes, the need for a fast, reliable and knowledge-based process layout becomes obvious. In this paper an innovative approach for determining milling process key data, using developed and consolidated modelling techniques, is suggested. Based on this data, a priori conclusions for a fast and effective milling process design are derived. Afterwards, the developed approach will be applied in frame of a case study, where a methodical machinability analysis of common turbomachinery materials is presented. Concluding, the approach is validated using real machining processes and findings are transferred towards applied milling process designing and manufacturing tasks.