Micro-Aspheric Mold Polishing Utilizing Magnetostrictive Vibration-Assisted Polishing Machine

Abstract:

Micro-aspheric lenses molded by micro-aspheric ceramic molds are increasing in the optical systems such as digital cameras and blu-ray players. To finish the molds with high accuracy and low surface roughness, in this paper, the micro-aspheric mold made of Electroless nickel plating are polished by using the newly developed 5-axis magnetostrictive vibration-assisted polishing machine. The magnetostrictive vibrating polisher generates a lateral vibration at 9.2 kHz with amplitude of 30 μm. The polishing pressure is controlled by a balance adjustment mechanism and the polishing load is controllable within a range of 2 mN ~ 20 mN with a resolution of 2 mN. The motion resolution of the X-Y-Z table is 0.1 μm in each direction. The C-axis rotary table is mounted on a B-axis tilting table and the workpiece is mounted on the C-axis rotary table with a vacuum chuck. According to the polishing experiments, the form accuracy was improved to 200 nm P-V and the surface roughness was reduced to 10 nm Rz (1 nm Ra).

• Periodical: Key Engineering Materials (Volumes 523-524)
• Pages: 768-773
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.523-524.768
• Online since: November 2012
• Authors: Jiang Guo, Hirofumi Suzuki, Shinya MORITA, Yutaka Yamagata, Toshiro Higuchi
• Keywords: Die, Mold, Polishing, Vibration

References

[1] Brinksmeier, E., Riemer, O., Gessenharter, A., 2006, Finishing of structured surfaces by abrasive polishing, Precision Engineering, 30/3: 325-336.

DOI: 10.1016/j.precisioneng.2005.11.012

[2] Komanduri, R., Lucca, D.A., Tani, Y., 1997, Technological Advances in Fine Abrasive Process. Annals of the CIRP, 46/2: 545–596.

DOI: 10.1016/s0007-8506(07)60880-4

[3] Brinksmeier, E., Riemer, O., Gessenharter, A., Autschbach, L., 2004, Polishing of Structured Molds, Annals of the CIRP, 53/1: 247-250.

DOI: 10.1016/s0007-8506(07)60690-8

[4] Brehl, D.E., Dow, T.A., 2008, Review of vibration-assisted machining, Precision Engineering, 32/3: 153-172.

DOI: 10.1016/j.precisioneng.2007.08.003

[5] Guo, J., Suzuki, H., Higuchi, T., 2011, Finishing of Micro Aspheric Molds by Vibration Assisted Polishing Using Magnetostrictive Material, Proceedings of 11th euspen International Conference, Lake Como, Italy, 1: 275-278.

[6] Guo, J., Suzuki, H., Morita, S., Yamagata, Y. and Higuchi, T., 2012, Micro Polishing of Tungsten Carbide using Magnetostrictive Vibrated Polisher, Key Engineering Materials, 516: 569-574.

DOI: 10.4028/www.scientific.net/kem.516.569

[7] Suzuki, H., Moriwaki, T., Okino, T., Ando, Y., 2006, Development of Ultrasonic Vibration Assisted Polishing Machine for Micro Aspheric Die and Mold. Annals of the CIRP, 55/1: 385–388.

DOI: 10.1016/s0007-8506(07)60441-7

[8] Suzuki, H., Hamada, S., Okino, T., Kondo, M., Yamagata, Y., Higuchi, T., 2010, Ultraprecision finishing of micro-aspheric surface by ultrasonic two-axis vibration assisted polishing, Annals of the CIRP, 59/1: 347-350.

DOI: 10.1016/j.cirp.2010.03.117

[9] Preston FW., 1927, The theory and design of plate glass polishing machines, J Soc Glass Technol, 11: 214–256.