Morphology of Cleaved Surface and Observation of In Situ Crack Propagation During Cleaving
Soshi Iwatsuki*, Hirofumi Hidai*,**,, Souta Matsusaka*, Akira Chiba*, and Noboru Morita*
*Department of Mechanical Engineering, Chiba University
1-33 Yayohi-cho, Inage-ku, Chiba 263-8522, Japan
**Molecular Chirality Research Center, Chiba University, Chiba, Japan
In laser cleaving, the thermal stress caused by laser heating and water-jet cooling propagates previously induced cracks in the workpiece material. The laser-cleaving conditions affect the quality of the fracture surface, and therefore, elucidating the relationship between the cleaved surface, cleaving conditions, and crack propagation is essential. Against this backdrop, in this study, we investigated the morphology of the cleaved surface and visualized the crack propagation and stress in situ using a high-speed polarization camera. The distance between the glass edge and cleaved surface was varied. When the laser-cleavage line was close to the glass edge, twist hackles were formed on the cleaved surface. The area in which the twist hackles formed on the cleaved surface coincided with the lagging section of the crack front. Furthermore, the twist hackle reached the specimen surface, and the edge of the surface exhibited a sawtooth shape. Observations with the high-speed polarization camera revealed that the internal stress was asymmetric with respect to the crack when the twist hackles were formed.
-  G. D. Quinn, “Fractography of Ceramics and Glasses,” National Institute of Standards and Technology, 960-16 3rd ed, doi: 10.6028/NIS.SP.960-16e3, 2016.
-  T. Ono and K. Tanaka, “Theoretical and quantitative evaluation of the cuttability of AMLCD glass substrates using a four-point-bending test,” J. Soc. Information Display, Vol.7, No.3, pp. 207-212, doi: 10.1889/1.1984477, 1999.
-  N. Tomei, K. Murakami, T. Fukunishi, S. Yoshida, and J. Matsuoka, “Direct observation of crack propagation in a liquid crystal display glass substrate during wheel scribing,” Int. J. Appl. Glass Sci., Vol.9, No.1, pp. 105-113, doi: 10.1111/ija.12272, 2017.
-  K. Imai, M. Saito, S. Matsusaka, Y. Matsumoto, H. Hidai, A. Chiba, and N. Morita, “Dynamic observation of crack generation during wheel scribing from lateral and back sides using a high-speed camera,” Precis. Engin., Vol.60, pp. 421-427, doi: 10.1016/j.precisioneng.2019.06.013, 2019.
-  C.-H. Tsai and C.-S. Liou, “Applying an on-line crack detection technique for laser cutting by controlled Fracture,” Int. J. Adv. Manuf. Tech., Vol.18, pp. 724-730, doi: 10.1007/s001700170015, 2001.
-  C.-H. Tsai and C.-J. Chen, “Application of iterative path revision technique for laser cutting with controlled fracture,” Opt. Lasers Engin., Vol.41, pp. 189-204, doi: 10.1016/S0143-8166(02)00147-1, 2004.
-  C.-H. Tsai and B.-C. Lin, “Laser cutting with controlled fracture and pre-bending applied to LCD glass separation,” Int. J. Adv. Manuf. Techn., Vol.32, pp. 1155-1162, doi: 10.1007/s00170-006-0422-9, 2007.
-  Y.-Z. Wang and J. Lin, “Characterization of the laser cleaving on glass sheets with a line-shape laser beam,” Opt. Laser Techn., Vol.39, pp. 892-899, doi: 10.1016/j.optlaste.2006.07.005, 2007.
-  K. Yamamoto, N. Hasaka, H. Morita, and E. Ohmura, “Three-dimensional thermal stress analysis on laser scribing of glass,” Prec. Engin., Vol.32, pp. 301-308, doi: 10.1016/j.precisioneng.2007.10.004, 2008.
-  S. Nisar, M. A. Sheikh, L. Li, and S. Safdar, “Effect of thermal stresses on chip-free diode laser cutting of glass,” Optics & Laser Technology, Vol.41, No.3, pp. 318-327, doi: 10.1016/j.optlaste.2008.05.025, 2009.
-  S. Nisar, L. Li, M. Sheikh, and A. Pinkerton, “The effect of continuous and pulsed beam modes on cut path deviation in diode laser cutting of glass,” Int. J. Adv. Manuf. Techn., Vol.49, pp. 167-175, doi: 10.1007/s00170-009-2373-4, 2010.
-  S. Nisar, M. A. Sheikh, L. Li, and S. Safdar, “The effect of material thickness, laser power and cutting speed on cut path deviation in high-power diode laser chip-free cutting of glass,” Opt. Laser Techn., Vol.42, pp. 1022-1031, doi: 10.1016/j.optlaste.2010.01.024, 2010.
-  C. Zhao, H. Zhang, L. Yang, Y. Wang, and Y. Ding, “Dual laser beam revising the separation path technology of laser induced thermal-crack propagation for asymmetric linear cutting glass,” Int. J. Machine Tools Manuf., Vol.106, pp. 43-55, doi: 10.1016/j.ijmachtools.2016.04.005, 2016.
-  T. Ueda, K. Yamada, K. Oiso, and A. Hosokawa, “Thermal Stress Cleaving of Brittle Materials by Laser Beam,” CIRP Annals, Vol.51, pp. 149-152, doi: 10.1016/S0007-8506(07)61487-5, 2002.
-  K. Yamada, T. Maeda, T. Iwai, K. Sekiya, and R. Tanaka, “Photoelastic observation of stress distributions in laser cleaving of glass substrates,” Prec. Engin., Vol.47, pp. 333-343, doi: 10.1016/j.precisioneng.2016.09.007, 2017.
-  T. Kawabe, T. Furumoto, Y. Hashimoto, T. Koyano, Y. Ochi, K. Oguchi et al., “Study on High Quality Thermal Stress Cleavage of Thick Sapphire Wafer,” Key Engineering Materials, Vol.825, pp. 39-44, doi: 10.4028/www.scientific.net/KEM.825.39, 2019.
-  K. Karube and N. Karube, “Laser-induced full body cleavage of flat-panel-display glass,” J. Soc. Inform. Display, Vol.17, pp. 323-329, doi: 10.1889/JSID17.4.323, 2009.
-  F. Motomura, Y. Imai, and A. Saimoto, “Using Laser-Based Thermal Stress Cleaving to Trim the Edges of Rectangular Glass Plates,” J. Jpn. Soc. Pre. Engin., Vol.75, pp. 1350-1354, doi: 10.2493/jjspe.75.1350, 2009 (in Japanese).
-  T. Onuma and Y. Otani, “A Dynamic Measurement System for Two-dimensional Birefringence Distribution with Sub-millisecond Time Resolution,” J. Jpn. Soc. Prec. Engin., Vol.78, pp. 1082-1086, doi: 10.2493/jjspe.78.1082, 2012 (in Japanese).
-  H. Hidai, R. Hasegawa, Y. Horie, A. Chiba, S. Matsusaka, T. Onuma, and T. Morita, “Dynamic Observation of Internal Stress and Crack Formation Process by Indentation on the Glass: Two Dimensional Observation with Wedge Shaped Indenter,” J. Jpn. Soc. Pre. Engin., Vol.83, pp. 381-386, doi: 10.2493/jjspe.83.381, 2017 (in Japanese).
-  S. Matsusaka, G. Mizobuchi, H. Hidai, A. Chiba, N. Morita, and T. Onuma, “Observation of Crack Propagation Behavior and Visualization of Internal Stress Field during Wheel Scribing of Glass Sheet,” J. Jpn. Soc. Pre. Engin., Vol.81, pp. 270-275, doi: 10.2493/jjspe.81.270, 2015 (in Japanese).
-  R. Hasegawa, S. Matsusaka, H. Hidai, A. Chiba, N. Morita, and T. Onuma, “In-process estimation of fracture surface morphology during wheel scribing of a glass sheet by high-speed photoelastic observation,” Precision Engineering, Vol.48, pp. 164-171, doi: 10.1016/j.precisioneng.2016.11.017, 2017.
-  S. Iwatsuki, H. Hidai, A. Chiba, S. Matsusaka, and N. Morita, “Examination of internal stress by photoelasticity in laser cleaving of glass,” Prec. Engin., Vol.64, pp. 122-128, doi: 10.1016/j.precisioneng.2020.03.019, 2020.
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