Spectral analysis of surface roughness features of a lapped ultraprecision single-point diamond machined surface

  • N. H. Yu
  • C. Y. ChanEmail author
  • L. H. Li
  • W. B. Lee


Single-point diamond turning of soft metals could provide a much shiny surface with an optimal feed rate; however, the machining mark would be left on the machined surface, which caused the roughness cannot be neglected. If the feed rate is too small, the roughness of the surface could be improved but the reflectiveness would be decreased because of damaging the profile. Therefore, it is necessary to develop a lapping method to reduce the roughness by removing the machining mark, while the reflectiveness can be kept at the original level simultaneously. In this study, the novel lapping method, using strands of wool fibers to deliver the abrasive slurry to rub against the lens, was proposed for removing the machining marks on the mold of a lenticular lens by lapping without damaging the profile of the mold. Even though the normal pressure applied by the wool strands onto the mold surface is very low, the coefficient of friction would be increased significantly with the application of the abrasive slurry. The combined effect was to provide a relatively large shear force to lap the surface with a minimal normal force. Therefore, the proposed method could theoretically avoid damaging the lens while effectively removing the irregularities that appeared on the surfaces. In order to evaluate the proposed lapping method, we firstly lapped the machining marks with different lapping parameters (speed, grit size, time, and pressure) to find out the relationship between these parameters and roughness with the same profile of the mold. Secondly, the optimal lapping parameters were designed based on the above lapping results to deduce the best lapping solution for processing the machining marks. Thirdly, the lapped surface profile of the mold was test by optical profiling system, and the features of the surface can be categorized into various spectral distribution groups. Finally, by comparing the variation of the spectral distribution groups, it is verified that based on our proposed methodology, selective removal of surface spectral groups of features becomes possible.


Lenticular lens Lapping Spatial frequency 


  1. 1.
    DIN 8589–15. Manufacturing process chip removal. Part 15. Lapping; classification, subdivisions, terms and definitions. German National Standard; 1985Google Scholar
  2. 2.
    Marinescu I, Ulhmann E, Toshiro D (2006) Handbook of lapping and polishing (1st ed) CRC Press ISBN 11 57444 670 3Google Scholar
  3. 3.
    Sanchez LEA, Jun NZX, Fiocchi AA (2011) Surface finishing of flat pieces when submitted to lapping kinematics on abrasive disc dressed under several overlap factors. Precis Eng 35(2):355–363CrossRefGoogle Scholar
  4. 4.
    Cao Z-C, Cheung CF (2014) Theoretical modelling and analysis of the material removal characteristics in fluid jet polishing. Int J Mech Sci 89:158–166CrossRefGoogle Scholar
  5. 5.
    Chen S, Li S, Hu H, Tie G, Guan C, Li Q (2015) Analysis of surface quality and processing optimization of magnetorheological polishing of KDP crystal. J Opt 44(4):384–390CrossRefGoogle Scholar
  6. 6.
    Guo J (2015) Corrective finishing of a micro-aspheric mold made of tungsten carbide to 50 nm accuracy. Appl Opt 54(18):5764–5770CrossRefGoogle Scholar
  7. 7.
    Yin Z, Yi Z (2015) Direct polishing of aluminum mirrors with higher quality and accuracy. Appl Opt 54(26):7835–7841CrossRefGoogle Scholar
  8. 8.
    Shiou F-J, Banh Q-N (2016) Development of an innovative small ball-burnishing tool embedded with a load cell. Int J Adv Manuf Technol 1–11Google Scholar
  9. 9.
    Chuang H-C, Tso P-L (2006) An investigation of lapping characteristics for improving the form error of an aspheric lens. J Mater Process Technol 176(1):183–190CrossRefGoogle Scholar
  10. 10.
    Lewandowski HS, Richard R (1989) An automated method for the preparation of orthogonal arrays for use in Taguchi designed experiments. Comput Ind Eng 17.1:502–507CrossRefGoogle Scholar
  11. 11.
    Choi S-G, Kim S-H, W-K Choi, E-S Lee (2015) The optimum condition selection of electrochemical polishing and surface analysis of the stainless steel 316L by the Taguchi method. Int J Adv Manuf Technol 1–7Google Scholar
  12. 12.
    Cheung CF, Ho LT, Charlton P, Kong LB, To S, Lee WB (2010) Analysis of surface generation in the ultraprecision polishing of freeform surfaces. Proc Inst Mech Eng B J Eng Manuf 224(1):59–73CrossRefGoogle Scholar
  13. 13.
    Wang H, To S, Chan CY, Cheung CF, Lee WB (2010) A theoretical and experimental investigation of the tool-tip vibration and its influence upon surface generation in single-point diamond turning. Int J Mach Tools Manuf 50(3):241–252CrossRefGoogle Scholar

Copyright information

© Springer-Verlag London 2016

Authors and Affiliations

  1. 1.The State Key Laboratory of Ultraprecision Machining Technology, Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityKowloonHong Kong

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