Empirical Modeling and Optimization of Laser Bending Process Parameters using the Central Composite Design Method for HDD Slider PSA/RSA Adjustment


This paper details the development and optimization of a laser adjustment process for the pitch static attitude and roll static attitude (PSA/RSA) to achieve the maximum bending angle without the burning of materials. The effects of process parameters (or factors) including the laser power, pulse repetition rate, and scanning time were investigated based on the central composite design method. Experiments were performed on a stainless steel (SST-300 series) suspension using a solid-state laser system and a charge-coupled device camera with image processing technology. Regression models of positive and negative PSA/RSA (or response) values were developed through a total of 20 experimental runs. The results showed that the PSA/RSA bending angle increases with increasing laser power and pulse repetition rate, while the bending angle decreases with increasing scanning time. The optimization determined that a higher laser power and lower scanning time had a more significant effect on the bending angle. However, the laser power cannot be increased above the melting point of the material, as this will lead to the formation of spongy debris on the stainless steel. The models were shown to accurately describe the relationship between the factors and responses. In addition, the laser bending mechanism for the PSA/RSA adjustment of a hard disk drive slider was investigated.

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  1. 1.

    Geiger, M., Vollertsen, F.: The mechanisms of laser forming. CIRP Ann. 42(1), 301–304 (1993)

    Article  Google Scholar 

  2. 2.

    Shi, Y., et al.: Research on the mechanisms of laser forming for the metal plate. Int J Mach Tool Manu. 46, 1689–1697 (2006)

    Article  Google Scholar 

  3. 3.

    Zhu, H., Bogy, D.B.: Effects of pitch static attitude and roll static attitude on the steady performance of air bearing slider. Proceedings of WTC2005. World Tribology Congress III, (2005) Retrieved from https://pdfs.semanticscholar.org/0c16/4e8b115432b8337b889f6357812c0f116a9e.pdf?_ga=2.11082813.823079323.1580444355-2096459228.1580444355. Accessed 28 Mar 2019

  4. 4.

    Bogy, D.B., Zeng, Q.H.: Effects of suspension limiters on the dynamic load/unload process: numerical simulation. IEEE Trans. Magn. 35, 2490–2492 (1999)

    Article  Google Scholar 

  5. 5.

    Kilian, S., Zander, U., Talke, F.E.: Suspension modeling and optimization using finite element analysis. Tribol. Int. 36(4–6), 317–324 (2003)

  6. 6.

    Takahashi, H., Bogy, D.B., Matsumoto, M.: Vibration of head suspensions for proximity recording. IEEE Trans. Magn. 34, 1756–1758 (1998)

    Article  Google Scholar 

  7. 7.

    Wilson, C.J., Bogy, D.B.: Modal Analysis of a Suspension Assembly. J. Manuf. Sci. E T. 116(3), 377–386 (1994)

    Google Scholar 

  8. 8.

    Weissner, S., Zander, U., Talke, F.E.: A new finite-element based suspension model including displacement limiters for load/unload simulation. J. Tribol.-T. 125(1), 162–167 (2003)

    Article  Google Scholar 

  9. 9.

    Kenichiro, A., Keiji, A.: Numerical ball swaging analysis of head arm for hard disk drives. Microsyst. Technol. 13, 943–949 (2007)

    Article  Google Scholar 

  10. 10.

    Boonpuang, R., et al.: Etching continuous periodic pattern on a suspension to adjust pitch and roll static attitude. United States Patent No. US009236071B1. (2016) Retrieved from https://patentimages.storage.googleapis.com/70/4c/da/3c8de4752390ec/US9236071.pdf. Accessed 28 Mar 2019

  11. 11.

    Zeng, Q.H.: Method for adjusting the pitch and roll static torques in a disk drive head suspension assembly. United States patent No. US7069156B2. (2006) Retrieved from https://patentimages.storage.googleapis.com/8a/49/8f/cd44bcb8d45227/US7069156.pdf. Accessed 28 Mar 2019

  12. 12.

    Gu, C., et al.: Investigation on bend displacement and surface quality induced by laser shock micro-adjustment. Appl. Surf. Sci. 270, 281–286 (2013a)

    Article  Google Scholar 

  13. 13.

    Gu, C., et al.: Numerical simulation and experimentation of adjusting the curvatures of micro-cantilevers using the water-confined laser-generated plasma. Opt. Lasers Eng. 51, 460–471 (2013b)

    Article  Google Scholar 

  14. 14.

    Yanjina, G., et al.: Laser micro-bending process based on the characteristic of the laser polarization. J. Mater. Process. Technol. 212, 662–671 (2012)

    Article  Google Scholar 

  15. 15.

    Zhang, X.R., Xu, X.: Laser bending for adjusting curvatures of hard disk suspensions. Microsyst. Technol. 11, 1197–1203 (2005)

    Article  Google Scholar 

  16. 16.

    Zheng, J., et al.: Heat transfer across a nanoscale pressurized air gap and its application in magnetic recording. Sci. Rep. 8, 3343 (2007). https://doi.org/10.1038/s41598-018-21,673-7

    Article  Google Scholar 

  17. 17.

    Zhu, H., et al.: Effects of pitch static attitude and roll static attitude on the steady performance of air bearing sliders. J. Tribol.-T. 129, 689–694 (2007)

    Article  Google Scholar 

  18. 18.

    Frieden, B.R.: Lossless conversion of a plane laser wave to a plane wave of uniform irradiance. Appl. Opt. 4, 1400–1403 (1965)

    Article  Google Scholar 

  19. 19.

    Raciukaitis, G., et al.: Laser processing by using diffractive optical laser beam shaping technique. JLMN. 6(1), 37–43 (2011)

  20. 20.

    Dubey, A.K., Yadava, V.: Multi-objective optimization of Nd:Y AG laser cutting of nickel-based super alloy sheet using orthogonal array with principal component analysis. Opt. Lasers Eng. 46, 124–132 (2008)

    Article  Google Scholar 

  21. 21.

    Venkadeshwaran, K., et al.: Bend angle prediction and parameter optimization for laser bending of stainless steel using FEM and RSM. IJMMS. 5(3/4), 308–321 (2012)

    Article  Google Scholar 

  22. 22.

    Vollertson. Mechanisms and models for laser forming. Proceedings of Laser Assisted Net shape Engineering Conference, p. 345–359 (1994)

  23. 23.

    Paunoiu, V., et al.: Laser Bending of Stainless Steel Sheet Metals. Int. J. Mater. Form. 1, 1371–1374 (2008)

    Article  Google Scholar 

  24. 24.

    Magee, J., Watkins, K., Edwardson, P., Dearden, G., French, P.: Laser forming of aerospace alloys. AMTC, Seattle, Society of Automotive Engineers, Paper, (2001–01), pp.: 2610 (2001)

  25. 25.

    Carlone, P., Palazzo, G.S., Pasquino, R.: Inverse analysis of the laser forming process by computational modelling and methods. Comput. Math. Appl. 55, 2018–2032 (2008)

    MathSciNet  Article  Google Scholar 

  26. 26.

    Lawrence, J.R.: Advances in Laser Materials Processing: Technology, Research and Application. Woodhead Publishing Limited, UK (2010)

  27. 27.

    Dearden, G., Edwardson, S.: Laser Assisted Forming for Ship Building, SAIL, Williamsburg (2003) Retrieved from https://citeseerx.ist.psu.edu/viewdoc/download?doi= Accessed 12 Feb 2020

  28. 28.

    Sadhukhan, B., et al.: Optimisation using central composite design (CCD) and the desirability function for sorption of methylene blue from aqueous solution onto Lemna major. Karbala Int. J. Mod. Sci. 2, 145–155 (2016)

    Article  Google Scholar 

  29. 29.

    Kant, R., et al.: Finite element simulation of laser assisted bending with moving mechanical load. IJMMS. 6(4), 351–366 (2013)

    Article  Google Scholar 

  30. 30.

    Lambiase, F., et al.: Optimization of Multi-Pass Laser Bending by means of Soft Computing Techniques. CIRP. 33, 502–507 (2015)

    Article  Google Scholar 

  31. 31.

    Lawrence, J., Schmidt, M.J.J., Li, L.: The forming of mild steel plates with 2.5 kW high power diode laser. Int. J Mach. Tool. Manu. 41, 967–977 (2001)

    Article  Google Scholar 

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Correspondence to Rachsak Sakdanuphab.

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Boonpuang, R., Mongkolwongroj, M., Sakulkalavek, A. et al. Empirical Modeling and Optimization of Laser Bending Process Parameters using the Central Composite Design Method for HDD Slider PSA/RSA Adjustment. Lasers Manuf. Mater. Process. 7, 290–304 (2020). https://doi.org/10.1007/s40516-020-00122-2

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  • HDD PSA/RSA optimization
  • Central composite design method
  • Laser bending process
  • Laser bending mechanism
  • Response surface methodology