Longitudinal micro-waviness (LMW) formation mechanism on large optical surface during ultra-precision fly cutting
- 58 Downloads
During fly cutting of large aperture flat optical components, mid-spatial frequency micro-waviness is formed on the machined surface, which greatly affects the optical performance of the components. This study aims to explore the mechanism of formation of micro-waviness perpendicular to the feed direction, which is called longitudinal micro-waviness (LMW). A finite element model (FEM) of the ultra-precision fly cutting spindle system is developed to analyze the axial vibrations of the tool nose. The analysis shows that the formation of LMW is the result of coupling of the response of the spindle system and its higher order natural frequency response under the excitation of the tangential cutting force. The vibration frequency of the tool nose is closely related to the structure of the spindle system. By changing the stiffness of the cutting head, the frequency is significantly changed, and the LMW formed on the machined surfaces has a spatial period of 39.2 mm, which is out of the range of mid-spatial frequency waviness. This result has great significance in the design of fly cutting machines, and can be used to improve the quality of the optical surface and thereby improve the performance of large aperture flat optical devices.
KeywordsFly cutting Aerostatic spindle system Micro-waviness Mid-spatial frequency
Unable to display preview. Download preview PDF.
The authors are grateful to Dr. Pengqiang Hu at the Harbin University of Science and Technology for his invaluable comments and suggestions. This work was financially sponsored by NSFC (Grant No. 51375122) and the Key laboratory foundation of high precision machining (Grant No. ZZ14002).
- 1.Wang X, Gao H, Chen Y, Guo D (2015) A water dissolution method for removing micro-waviness caused by spdt process on kdp crystals. Int J Ad Manufacturing Technol 85(5):1–14Google Scholar
- 3.Hawley-Fedder RA, Geraghty P, Locke SN, McBurney MS, Runkel MJ, Suratwala TI, Whitman PK (2004) NIF pockels cell and frequency conversion crystals. In Proceedings of SPIE 5341(1):121–126Google Scholar
- 5.Wang S-F, Fu P-Q, Zhang F-H, An C-H et al (2014) Investigation of surface micro-waviness in single point diamond fly cutting. J Harbin Inst Technol ( New Series) 21(5):119–123Google Scholar
- 6.Chen M, Li M, Jiang W, Xu Q (2010) Influence of period and amplitude of microwaviness on kh2po4 crystal’s laser damage threshold. J Appl Phys 108(4):478–279Google Scholar
- 14.Chen D, Fan J, Zhang F (2012) Dynamic and static characteristics of a hydrostatic spindle for machine tools. J Manuf Syst 31(1):26–33. https://doi.org/10.1016/j.jmsy.2010.11.006
- 15.Ni J (1985) Dynamic stability and debugging of aerostatic-pressurized bearings in magnetic disk comprehensive instrumentation. J Huazhong Univ Sci Technolog Med Sci 13(3):69–74Google Scholar
- 21.Fu P (2013) Characterization of the effect of fly cutting machine spindle properties on surface waviness and the development of a new dynamic testing system. Master thesis. Harbin Institute of TechnologyGoogle Scholar
- 22.Zhan l (2015) Simulation and experimental study of KDP crystal surface topography formation in ultra-precision fly cutting machining. Master thesis. Harbin Institute of TechnologyGoogle Scholar