An investigation of effect of stand-off distance on the material removal characteristics and surface generation in fluid jet polishing

Abstract

Fluid jet polishing (FJP) is a versatile polishing process that has many advantages compared to other polishing processes. Stand-off distance (SOD) is one of the key parameters in fluid jet polishing. However, relatively little research work has been carried out to investigate its effect of SOD on material removal characteristics and surface generation in FJP. In this paper, a systematic investigation of the effect of SOD on the tool influence function and surface topography in FJP was conducted. Experiments were designed for FJP two kinds of materials corresponding to ductile and brittle materials. They are nickel copper (NiCu) alloy and BK7 optical glass, respectively. In this study, the SOD was varied from 2 to 35 mm. Analysis and discussions were made on its effect on the shape of TIF, material removal rate, and surface topography. It is interesting to note that the TIF shape becomes a Gaussian-like shape with large SOD both on NiCu and BK7, which provides a novel way to optimize the TIF in FJP. The variation of the material removal rate and surface roughness versus SOD on NiCu and BK7 were also determined from the experimental results. Moreover, the surface topography of NiCu and BK7 were characterized from the results measured from the white light interferometer and scan electron microscope. The outcome of the study provides a better understanding of the material removal characteristics and surface generation mechanism in FJP.