Experimental study of surface integrity in ultrasonic vibration–assisted milling of GH4169 nickel-based superalloy

GH4169 nickel-based high-temperature alloy demonstrates excellent mechanical, chemical, thermal shock, and mechanical load resistance properties. However, it is typically a difficult-to-machine material. Ultrasonic vibration–assisted milling can effectively solve the machining challenges of GH4169 nickel-based high-temperature alloy and improve surface integrity. Herein, the motion model of the tool-tip under ultrasonic vibration assistance is established. The tool-tip motion trajectory and chip separation law are analyzed. The effect of ultrasonic vibration on surface integrity is investigated through ultrasonic vibration–assisted milling experiments. The results show that residual surface stress stimulates at high milling speed, depth of cut, and feed rate, while it progressively decreases with ultrasonic amplitude. The machined surface hardening enhances with the addition of ultrasonic amplitude. The machined surface roughness increases with the growth of milling speed, feed rate, and ultrasonic amplitude, and decreases with the rise of cutting surface roughness increases with the addition of milling speed, feed rate, and ultrasonic amplitude, and falls with the rise of cutting depth.