Vibration coupling effects and machining behavior of ultrasonic vibration plate device for creep-feed grinding of Inconel 718 nickel-based superalloy

Ultrasonic vibration-assisted grinding (UVAG) is an effective and promising method for machining of hard-to-cut materials. This article proposed an ultrasonic vibration plate device enabling the longitudinal full-wave and transverse half-wave (L2T1) vibration mode for UVAG. The characteristics of two-dimensional coupled vibration in different directions were analyzed on the basis of apparent elastic method and finite element method. Furthermore, a correction factor was applied to correct the frequency error caused by the apparent elastic method. Finally, the comparative experiments between the conventional creep-feed grinding and UVAG of Inconel 718 nickel-based superalloy were carried out. The results indicate that the apparent elastic method with the correction factor is accurate for the design of plate device under the L2T1 vibration mode. Compared with the conventional creep-feed grinding, the UVAG causes the reduction of grinding force and the improvement of machined surface quality of Inconel 718 nickel-based superalloy. Furthermore, under the current experimental conditions, the optimal ultrasonic vibration amplitude is determined as 6 μm, with which the minimum surface roughness is achieved.