Ziqiang Yin

Topography simulation and vibration analysis of ultra-precision diamond flycutting micro V-groove

Ultra-precision diamond flycutting is an important method to manufacture micro V-groove with sub-micrometer form accuracy. The relative vibration between the tool and the work piece is one of the most critical factors which determine the manufacturing precision during the flycutting process. In order to restrain the vibration influence, a vibration analysing method in flycutting process is presented. The dynamical model of micro V-groove is established according to the character of ultra-precision diamond flycutting. Three-dimensional topography is simulated with and without vibration. The V-groove surface roughness is analysed based on the spatial frequency spectrum. Ultra-precision flycutting experiments are carried out, and the V-groove surface roughness is measured by the stylus profilometer along the V-groove. The vibration is identified on the basis of spectrum analysis results. The vibration character of flycutting system is obtained, and the cutting parameters are optimised.

Research on the tool alignment error in fabrication of off-axis paraboloid surfaces by using slow-tool-servo technique

Fabrication of free-form optics in good quality and high efficiency is much demanded as the widely use of free-form surfaces in modern optical systems. Slow-tool-servo technique is able to fabricate free-form optics with sub-micrometric form accuracy and nanometric surface finish in high efficiency, which has broad prospects of application. The tool alignment error is an important factor to work on the form accuracy of free-forms fabricated by slow-tool-servo technique. This paper studies the tool alignment error, presents a quantitative description of tool alignment errors at both feed and height directions by using the concept of the sensitivity function. An off-axis paraboloid workpiece was fabricated, and measure results verified the point of view in the paper. The tool alignment errors at two directions were calculated by surface figure error data to guide the alignment of cutting tool.