Effect of radial high-speed ultrasonic vibration cutting on machining performance during finish turning of hardened steel

Hardened steel has been widely used in the aviation and automotive fields owing to its unique properties. However, the poor machining performance for finishing hardened steel owing to low attainable cutting speeds and rapid tool wear has become a bottleneck in the functional performance and range of applications. In this study, a radial high-speed ultrasonic vibration cutting (R-HUVC) process was adopted for improving the machining performance of finishing hardened steel. R-HUVC involves the use of radial ultrasonic vibrations which ensure the separation of the tool and workpiece. The kinematics of R-HUVC were analyzed through a theoretical model, and its surface generation mechanisms in the intermittent cutting mode were studied. Then, finish turning experiments were conducted on the cutting force, surface roughness, and tool life to validate its machining performance compared to that of conventional cutting (CC) for a wide range of finishing conditions. The experimental results showed that R-HUVC can realize a lower cutting force, longer tool life, and better surface roughness compared to CC. It was verified that R-HUVC can be applied to high-speed machining for the finish turning of hardened steel because it improves the machining performance.