A comparative experimental study on the rough machining methods of centrifugal three-dimensional impellers

In this study, the processing efficiency and cost of centrifugal 3-D impeller rough machining using five-axis flank milling, linear shaft linkage high-speed milling and fixed-axis plunge milling were assessed. Furthermore, the nylon material cutting test was carried out to verify the geometrical precision of the fixed-axis plunge milling toolpath planning method used for the centrifugal 3-D impeller. Meanwhile, an empirical model for estimating the cutting force in plunge milling was established via the orthogonal cutting test. This ensured the smooth operation of the subsequent fixed-axis plunge milling cutting test. Cutting parameter optimisation and tool strength verification were performed for the impeller inlet, which was narrow and deep. On this basis, cutting tests for three FV520B impeller passages were conducted using the above-mentioned three methods. The results revealed that fixed-axis plunge milling exhibited a relatively large advantage regarding processing efficiency and cost. Additionally, the advantages were more obvious when the fixed-axis plunge milling was performed with a large-sized cutter.