Cutting of Ceramic Plates by Means of Spherical Surfaces

Research Project

Project/Area Number	05650127
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	機械工作・生産工学
Research Institution	Nihon University
Principal Investigator	HASHIMOTO Atsushi Nihon Univ., Coll.of Eng., Lecturer, 工学部, 講師 (70172856)
Co-Investigator(Kenkyū-buntansha)	IMAMURA Senji Nihon Univ., Coll.of Eng., Assoc.Prof., 工学部, 助教授 (10060154)
Project Period (FY)	1993 – 1994
Project Status	Completed (Fiscal Year 1994)
Budget Amount *help	¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 1994: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1993: ¥1,500,000 (Direct Cost: ¥1,500,000)
Keywords	Ceramics / Cutting / Fracture / Crack Propagation
Research Abstract	Concerning the development of a method for simultaneously cutting a large number of desired small shapes from ceramic plates, the following research results were obtained. The method presented is based on the use of two spherical surfaces, one being convex, the other being concave, and both being of the same radius of curvature. A ceramic plate (on which a line has been notched to define the shape of the desired cut) is interposed between the two spherical surfaces. If a compressive load is applied to the ceramic plate by way of the spherical surfaces, the ceramic plate becomes deformed along the point of contact of the spherical surfaces. Therefore, the bending moment will depend on the proportions relative to the spherical curvature, and furthermore, it will also depend on the presence of cracks in the ceramic plate along the notched line, and the extending of the crack along the entire length of the notch line to produce a line fracture in the ceramic plate. This method is an application which takes advantage of the progress of natural cracks occurring at the bending fractures of ceramic plates. In order to use this method, the proper curvature must be determined in advance and implemented in the spherical surfaces. With such a curvature having been implemented, a crack leading to a line francture can be produced in a single stroke of plate compression, and we can thereby simultaneously cut desired shapes from the ceramic plate. The significant characteristics of this method are that the cutting is done without generating noise or dust, the amount of energy required is very small, and the cutting time is very short. Therefore, it may be concluded that the cutting process presented here will be contributory to the improvement of productivity in the ceramics machining industry.