Study on the adaptability of elliptic continuous high-speed ultrasonic vibration cutting for complex rotating parts made of FGH96

Continuous cutting cannot open the cutting area; therefore, cutting fluid cannot enter the region for cooling and lubrication. The resulting high cutting temperature and force reduce cutting speed, thereby lowering machining efficiency. Partial separation continuous high-speed ultrasonic vibration cutting (C-HUVC) significantly improves machining efficiency by partially opening the cutting area during continuous cutting. However, when the tool vibrates along the cutting depth direction, the impact force on the tool becomes large, readily accelerating tool wear. During face turning (FT) and cylindrical turning (CT) of complex rotating parts, the direction of feed and cutting depth change; therefore, C-HUVC cannot meet the high-efficiency cutting requirements of complex rotating parts. To address this limitation, this study proposes an elliptical continuous high-speed ultrasonic vibration cutting (EHUVC) method. When FT and CT are performed using this method, the tool obliquely impacts the machined surface along the spiral trajectory; therefore, the impact force is small. In this study, the tool wear and surface integrity of the EHUVC method in turning FGH96 complex rotating parts were studied, and the mechanism for improving machining efficiency while preserving surface integrity was analyzed experimentally. The surface integrity of the production benchmark was obtained at a cutting speed of 50 m/min and a coolant pressure of 0.7 MPa. When machining FGH96 with a coolant pressure of 5 MPa, the cutting speed can be increased to 80 m/min using conventional cutting (CC) and 138 m/min using EHUVC, while maintaining surface integrity comparable to the production benchmark. Compared with CC, the machining efficiency achieved by EHUVC improved by 72.5%. The proposed EHUVC method satisfies the high-efficiency cutting requirements for complex rotating parts.