An experimental investigation of effect of process parameters on materials removal characteristics in fluid jet polishing

Fluid Jet Polishing (FJP) is a promising ultra-precision machining technology which shows great potential with regard to the application value in the generation of freeform surfaces with sub-micrometre form accuracy and nanometric surface finish. The polishing tool influence function (TIF), which is affected by various parameters and commonly assessed in terms of width, maximum depth and volumetric material removal rate, is critically required for corrective polishing and deterministic machining. In this study, a series of experiments was conducted to study the effect of various process parameters on the polishing tool influence function. The polishing machine used is a Zeeko IRP 200 ultra-precision freeform polishing machine, with three linear axes and three rotational axes. All polishing experiments were performed on BK7, which is one of the most common technical optical glass materials for high-quality optical components in the visible range. These specimens were polished using Al2O3 (Aluminium oxide) abrasive particles and measured by a Zygo Nexview 3D Optical Surface Profiler. All these experiments were conducted by changing one process parameter and keeping the other process parameters constant. In this paper, the experimental results are described in detail to show the relationships between the material removal and the various parameters (i.e. slurry pressure, standoff distance, impingement angle, etc.), and some interesting experimental results are explained.