Numerical and Experimental Investigation of the Form Maintainability of Structured Array Surfaces in Maskless Fluid Jet Polishing

Structured array surfaces (SAS) can achieve special functions through technical design in different fields such as electronics, optics, and precision molds. To achieve high performance of SAS, it is essential to improve its surface quality by postprocessing while retaining high form accuracy. Due to the small size of the structured surface features, it is hard for the
machine tool to contact the surface uniformly and it may inevitably affect the form accuracy of the polishing surfaces. Maskless fluid jet polishing (MFJP) is a promising finishing method due to its superior shape-adaptive capacity even for small-size
structures. In this paper, MFJP was utilized to obtain SAS with nanometric surface roughness and sub-micrometer form accuracy. The effect of jet impinging angle on the form maintainability of SAS was elucidated by computational fluid dynamics
(CFD) simulation and validated by a series of polishing experiments. Finally, three strategies were proposed to improve the form maintainability in the MFJP of SAS. This study can provide some theoretical basis for the ultra-precision manufacturing of SAS regarding form accuracy control.