Wet-Etching Evaluation Method of Subsurface Damage after Grinding of Glass
Large-aperture lens used for single-lens reflex cameras is generally produced by both ultra-precision grinding and polishing because a mass-produced lens by molding process can hardly achieve the required form accuracy and surface quality. Recently, grinding process of an optical glass should make surface quality as high as possible in order to reduce removal amount in polishing process. Accordingly, evaluation of subsurface damage induced under various grinding conditions has been required because subsurface damage leads to crack initiation or deterioration of the performance. However, evaluation method of subsurface damage on the spherical glass lens after grinding has not yet been established.In this study, the quantitative evaluation method by applying wet-etching of hydrofluoric acid (HF) is proposed, then its validity is verified. From the experimental results, we clarify to evaluate the subsurface damage by examining the surface transition according to etching time.
Hon-Zong Choi, Haedo Jeong, Xiping Xu and Hideki Aoyama
R. Sekiguchi et al., "Wet-Etching Evaluation Method of Subsurface Damage after Grinding of Glass", Advanced Materials Research, Vol. 1136, pp. 503-508, 2016
R. Sekiguchi, S. Yoshikawa, K. Higashi, N. Miki, Y. Kakinuma, M. Fukuta, K. Tanaka, "Wet-Etching Evaluation Method of Subsurface Damage after Grinding of Glass", Advanced Materials Research, Vol. 806, pp. 503-508, Nov. 2015