Ultra-precision machining by the hydrodynamic polishing process

This study will examine the feasibility of applying the hydrodynamic polishing (HDP) process as an ultra-precision machining method, which is aimed to compensate the form error of a work surface so that the form precision is improved. To be an ultra-precision machining method, the HDP process is required to have a deterministic machining nature and to have the capability to machine an arbitrary shape. From the machining mechanism, four sets of parameters that dominate the deterministic properties of the process are identified. It is clearly demonstrated from the experimental study that the HDP process is deterministic if the identified parameters are well controlled. To machine an arbitrary shape, a machining principle is proposed. From this principle, a square slot with uniform depth and a semi-cylindrical profile with parabolic cross-section can be accurately obtained by the HDP process. Hence, the HDP process can be a promising method to compensate form error for the ultra-precision purpose.