Pressure-dependent material removal rate model of fluid jet polishing

Abstract

The material removal characteristics exhibit a strong dependence on the applied jet pressure in fluid jet polishing. High jet pressure contributes to high polishing efficiency but deteriorates surface quality. Consequently, it is essential to appropriately control the jet pressure to achieve both high surface quality and accurate material removal, such as subsurface damage layer. Currently, there is a lack of accurate models that reveal the numerical correlation between the material removal rate and the jet pressure. The process of determining material removal rates often involves costly and time-consuming trial-and-error experiments. This paper presents a mathematical model for the pressure-dependent material removal rate, developed through force analysis and Computational Fluid Dynamics (CFD) simulations. The findings indicate that the material removal rate has a linear relationship with the jet pressure raised to a power of k. The value of k is influenced by the unique attributes of the workpiece and abrasives. The validity of this theoretical model is confirmed by conducting polishing tests under varying conditions, including different jet impinging angles, workpiece materials, and types of abrasives. The experimental results closely mirror those predicted by the physical model. This research deepens the comprehension of how jet pressure influences material removal, aiding in the fine-tuning of polishing parameters and minimizing the necessity for a multitude of initial experiments. Moreover, achieving deterministic material removal under a constant feed rate can be accomplished by controlling the jet pressure instead of the dwell time, eliminating the instability of the motion system caused by high acceleration speeds.