Paper:
Development of Removal Amount Estimation Method Based on Calculation of Elastic Deformation of Superabrasive Stones During Multistage Superfinishing of Sapphire
Naomichi Furushiro*,†, Tomomi Yamaguchi*, Daisuke Hirooka*, Masashi Yamaguchi*, Noboru Matsumori**, and Kenichi Tanada**
*Department of Mechanical Engineering, Kansai University
3-3-35 Yamate-cho, Suita-shi, Osaka 564-8680, Japan
†Corresponding author
**Mizuho Co., Ltd., Kyoto, Japan
In planarization processes of sapphire, lapping process takes a long time because sapphire is a hard material. In contrast, superfinishing, which involves fixed abrasive machining, can substitute for lapping, and it would be possible to shorten the amount of processing time. In this work, vitrified-bonded diamond superabrasive stones with different grain diameters are developed. Then, multistage superfinishing is investigated by combining these stones. Results indicate that the multistage process is capable of producing a 2 nmRa surface, equivalent of a lapped surface in less than 10 min. To improve the process of multistage superfinishing, a removal amount estimation method is developed based on the real contact pressure calculation. The working area ratio of the stone was calculated by considering elastic deformation during superfinishing. The contact ratio of sapphire is calculated considering the roughness of the pre-finished surface and grain depth of cut. Accordingly, the real contact pressure is calculated to estimate the removal amount during superfinishing and finished surface roughness was expected.
- [1] I. Akasaki, H. Amano, Y. Koide, K. Hiramatsu, and N. Sawaki, “Effects of ain buffer layer on crystallographic structure and on electrical and optical properties of GaN and Ga1-xAlxN (0<x≤0.4) films grown on sapphire substrate by MOVPE,” J. of Crystal Growth, Vol.98, No.1-2, pp. 209-219, 1989.
- [2] M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Japanese J. of Applied Physics, Vol.41, No.12B, L1431, 2002.
- [3] S. Nakamura, S. Pearton, and G. Fasol, “The blue laser diode: the complete story,” Springer Science & Business Media, 2013.
- [4] J. S. Lin and L. B. Weckesser, “Thermal shock capabilities of infrared dome materials,” APL Technical Digest, Vol.13, No.3, pp. 379-385, 1992.
- [5] J. S. Lyons, J. Liu, and M. A. Sutton, “High-temperature deformation measurements using digital-image correlation,” Experimental Mechanics, Vol.36, No.1, pp. 64-70, 1996.
- [6] D. C. Harris, “Durable 3–5 μm transmitting infrared window materials,” Infrared Physics & Technology, Vol.39, No.4, pp. 185-201, 1998.
- [7] G. Wang, M. Zhang, J. Han, X. He, H. Zuo, and X. Yang, “High-temperature infrared and dielectric properties of large sapphire crystal for seeker dome application,” Crystal Research and Technology, Vol.43, No.5, pp. 531-536, 2008.
- [8] M. S. Akselrod and F. J. Bruni, “Modern trends in crystal growth and new applications of sapphire,” J. of Crystal Growth, Vol.360, pp. 134-145, 2012.
- [9] M. Uneda, K. Takano, K. Koyama, H. Aida, and K. Ishikawa, “Investigation into chemical mechanical polishing mechanism of hard-to-process materials using a commercially available single-sided polisher,” Int. J. Automation Technol., Vol.9, No.5, pp. 573-579, 2015.
- [10] H. Tsuwa, “Kikai-Kakou-Gaku,” p. 266, Yokendo, 1973 (in Japanese).
- [11] S. Tanaka, N. Furushiro, D. Hirooka, T. Yamaguchi, N. Matsumori, and H. Ogura, “Superfinishing performance of sapphire with mechanochemical superabrasive stones,” 2014 JSPE Spring Conf., pp. 645-646, 2014 (in Japanese).
- [12] F. W. Preston, “The theory and design of plate glass polishing machines,” J. of the Society of Glass Technology, Vol.11, pp. 214-256, 1927.
- [13] E. J. Terrell and C. F. Higgs, “Hydrodynamics of slurry flow in chemical mechanical polishing a review,” J. of the Electrochemical Society, Vol.153, No.6, pp. K15-K22, 2006.
- [14] T. I. Suratwala, M. D. Feit, and W. A. Steele, “Toward deterministic material removal and surface figure during fused silica pad polishing,” J. of the American Ceramic Society, Vol.93, No.5, pp. 1326-1340, 2010.
- [15] M. Higuchi, A. Yano, and Y. Tanaka, “One Aspect of Grinding Wheel Elasticity in the Contact Zone: Study on the Mechanical Properties of Grinding Wheel (2nd Report),” J. of the Japan Society of Precision Engineering, Vol.43, No.511, pp. 801-806, 1977 (in Japanese).
- [16] D. P. Saini and R. H. Brown, “Elastic deflections in grinding,” CIRP Annals-Manufacturing Technology, Vol.29, No.1, pp. 189-194, 1980.
- [17] W. B. Rowe, M. N. Morgan, H. S. Qi, and H. W. Zheng, “The effect of deformation on the contact area in grinding,” CIRP Annals-Manufacturing Technology, Vol.42, No.1, pp. 409-412, 1993.
- [18] Z. B. Hou and R. Komanduri, “On the mechanics of the grinding process–Part I. Stochastic nature of the grinding process,” Int. J. of Machine Tools and Manufacture, Vol.43, No.15, pp. 1579-1593, 2003.
- [19] K. Nakamura, A. Yoshitani, S. Shimizu, and H. Sakamoto, “Proposition of High Accuracy Identification Method of Contact Stiffness of Joint,” Trans. of the Japan Society of Mechanical Engineers Series C, Vol.79, No.807, pp. 4389-4399, 2013 (in Japanese).
- [20] K. Okamura, T. Nakajima, and K. Yamamoto, “Study on the Cutting Mechanism of Abrasive Grain (5th Report): An Investigation of Cutting Processes in Circular Cutting,” J. of the Japan Society of Precision Engineering, Vol.33, No.387, pp. 237-244, 1967 (in Japanese).
- [21] Y. Tanaka, H. Tsuwa, and S. Kawamura, “Effects of Grinding Conditions on the Performance of Grinding Wheels (1st Report),” J. of the Japan Society of Precision Engineering, Vol.30, No.358, pp. 845-850, 1964 (in Japanese).
- [22] H. Yasui, Y. Tanaka, K. Maruo, T. Kamiya, and R. Sakamoto, “Development of Automatic Evaluation System for Working Surface of Super Abrasive Wheel (1st Report): Building of Automatic Image Processing Evaluation System for Whole Grinding Wheel Surface,” J. of the Japan Society of Precision Engineering, Vol.74, No.12, pp. 1313-1317, 2008 (in Japanese).
- [23] J. A. Randi, J. C. Lambropoulos, and S. D. Jacobs, “Subsurface damage in some single crystalline optical materials,” Applied Optics, Vol.44, No.12, pp. 2241-2249, 2005.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 Internationa License.