An experimental investigation of surface generation using an integrated ultra-precision polishing process and different polishing trajectories

Ultra-precision freeform polishing (UPFP) is an emerging technology for the machining of ultra-precision freeform surfaces with submicrometre form accuracy and surface roughness in the nanometre range. However, our understanding of the surface generation and process planning for UPFP is still far from complete. This paper presents an experimental study of the surface generation for different polishing processes, which include mechanical polishing (MP) and fluid jet polishing (FJP). In addition, the generation of desirable structured surfaces of UPFP has also been experimentally investigated to examine if different trajectory planning affects surface hydrophobicity. The experimental results show that both MP and FJP can produce similar surface roughness but differences in surface texture after polishing. Desirable surface roughness and structured surfaces can be produced by appropriate planning and control of the combination of MP and FJP, and tool path trajectories in UPFP. The results also prove that tool path trajectories affect the hydrophobicity of polished surfaces. The results provide an important means for the development of an integrated polishing process to achieve the desirable surface roughness and surface texture based on process planning and control in UPFP.