On mechanism of tool-workpiece separation in multi-dimensional vibration-assisted milling

Abstract

As an innovative manufacturing technique, vibration-assisted milling (VAMILL) can enhance machining performance like improving cutting efficiency, surface quality, and tool life through controlling tool-workpiece separation. Available analyses on mechanism of VAMILL primarily focus on one-dimensional vibration assistance and often ignore the crucial influence of tool geometry on the cutting trajectories, leading to incomplete characterization of tool-workpiece separation conditions. This paper comprehensively investigates the mechanisms of tool-workpiece separation in multi-dimensional VAMILL through theoretical analysis and finite element simulation. A novel kinematic model is developed to identify the separation phenomena across one-, two-, and three-dimensional (1-D, 2-D, and 3-D) vibration configurations, incorporating the effects of tool geometry and rotation. Specific mathematical models are developed for distinct separation mechanisms, and quantitative formulas are derived to calculate separation time, re-engagement time, and separation time ratio across various trajectory patterns and vibration parameters. The calculation results are validated through finite element simulations, demonstrating excellent agreement with theoretical calculations with errors below 12 %. The findings provide quantitative criteria for initiating and controlling tool-workpiece separation in multi-dimensional VAMILL, enabling precise process parameter selection for optimal machining performance.