Observation and analysis of subsurface damage of ground glass edge

• Main Author: Xie, TianGe.
• Other Authors: Zhong Zhaowei
• Format: Theses and Dissertations
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/54776
• Institution: Nanyang Technological University

Liquid Crystal Display (LCD) has replaced Cathode Ray Tube (CRT) as the mainstream display. The demand of LCD screen will maintain a rapid growth in next decade. Increased competition in such competitive markets derives LCD manufacturers as well as their raw material suppliers such as sheet glass manufacturers to make every effort to improve quality and production yields. Chamfering is one of key steps of glass substrate fabrication which restrict the quality and product output of LCD. The high-speed-edge grinding was emerged for this request of glass substrate industry. But one important issue should be concerned is subsurface damage (SSD) induced by the edge grinding process which strongly influence the mechanical strength and quality of displays. Furthermore, glass is very sensitive to the microcracks of the processed surface due to the hard and brittle nature. In order to investigate the factors of SSD generated in the edge grinding process, two special designed grinding wheels with different grit size were employed to shape the edge of ultra-thin normal glass panel and LCD-glass panel with 12 groups of grinding parameters. The cross-sectional microscopy as the simple and direct assessment method of SSD was utilized to measure the depth of subsurface cracks. In this study, it is found that SSD is more sensitive to wheel specification including grit size and bonding material. Grinding parameters like wheel speed, feed rate and depth of cut had small influence on SSD. At the same time, theoretical calculation of critical depth of cut and undeformed chip thickness combined with the pictures of optical observation, the grinding mechanism were divided to three groups: ductile-mode, partial ductile-mode and brittle-mode.