Understanding the high-point formation mechanism on large optical surface during ultra precision fly cutting process
- 72 Downloads
It was found that there always exists high points during cutting in and cutting out in the fly cutting of potassium dihydrogen phosphate (KDP) crystals. This results in poor surface flatness of KDP devices and degrades their optical performance. It is believed that the high-point formation are related to the cutting heat; however, the manner in which the cutting heat produces the high points and its control are still unclear. A thermomechanical model of the tool system in the fly cutting process is established to reveal the high-point formation mechanism on a large optical surface during the ultra-precision fly cutting process. The temperature field distribution of the tool system and axial displacement variation due to thermal deformation are solved and analyzed. The results indicate that the slow cutting heat accumulation caused by the discontinuous fly cutting process leads to moving of the cutting point in the axial direction, which is the main reason for the height difference during the process. Further analysis demonstrates that moving of the cutting point is primarily caused by the thermal deformation of the tool holder, not the tool or tool handle. Therefore, reducing the tool holder thermal deformation is the key to further improving the surface flatness of the workpiece. This study is of great significance for the improvement of the surface quality of large aperture optical devices in fly cutting.
KeywordsUltra-precision fly cutting Surface flatness FEM simulation Height difference
Unable to display preview. Download preview PDF.
This work was financially sponsored by the NSFC (Grant No. 51375122) and the Key Laboratory Foundation of High Precision Machining (Grant No. ZZ14002).
- 3.Hawleyfedder RA, Mcburney MS, Runkel MJ, Suratwala TI (2004) NIF Pockels cell and frequency conversion crystals. Proc. SPIE 5341, Optical Engineering at the Lawrence Livermore National Laboratory II: The National Ignition Facility 5341(33): 121–126Google Scholar
- 6.Miao J, Yu D, An C, Ye F, Yao J (2016) Investigation on the generation of the medium-frequency waviness error in flycutting based on 3D surface topography. Int J Adv Manuf Technol 1–9Google Scholar
- 8.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 Adv Manuf Technol 85(5):1–14Google Scholar
- 10.Gibson AO, Stein JL (1996) A linear observer based approach for estimation spindle bearing loads. Proc ASME Dyn Syst Control Div:251–258Google Scholar
- 14.Shaw MC (1984) Metal Cutting Principles. Oxford University PressGoogle Scholar
- 15.Zhan Lan (2015) Simulation and experimental study of KDP crystal surface topography formation in ultra-precision fly cutting machining, Harbin Inst Technol:11–14Google Scholar