Investigation on the formation mechanism and controlling method of machined surface topography of ultra-precision flycutting machining

The three-dimensional topography of machined surface induced by machine tool vibration has a great impact on the optical performance of ultra-precision optical components. This paper aims to explain the formation mechanism of the wavy topography of the machined surface of ultra-precision flycutting. Firstly, a dynamic model of the machine tool was built based on finite element method (FEM) considering the fluid-structure interaction (FSI) effect. Then, a mathematic model for simulating the machined surface topography was built based on the FEM model of the machine tool. The machined surface topography was simulated, and the spatial periods of waviness errors were analyzed based on power spectral density (PSD) method. The reason of waviness errors on machined surface was revealed by investigating the internal relationship between the spatial period of waviness error and the dynamic performance of the machine tool. Moreover, the method for controlling the spatial period of waviness error was discussed, which provides guidance for improving the optical performance of large size optical component.