(A) study on the analysis of grinding mechanism and development of dressing system by using optimum in-process electrolytic dressing

Abstract

This thesis suggests a new optimum in-process electrolytic dressing and the grinding mechanism using this optimum dressing system. Recently, developments in the frontier industry have brought a rapid increase in the use of brittle materials such as silicon wafer, ferrite, sintered carbide, MgO single crystal and die steel. Because of high hardness and brittleness the cracking and chipping are apt to generate in the grinding of brittle materials. Lapping and polishing are used for mirror surface generation of these materials, but have replaced gradually the high precision grinding. The mirror-like grinding is possible using the superabrasive wheel of more than grit No. 1000. The dressing of the superabrasive wheel for the mirror-like grinding is difficult owing to loading and glazing. In-process dressing using electrolysis as developed in recent years has achieved an effective grinding, but with a defect of the dressing current change owing to the lapse of time and the unstable dressing condition. In this thesis, the optimum system of in-process electrolytic dressing controlled by computer was developed for improving the defects, and could maintain the optimum dressing condition at all times. The control of in-process dressing was simplified using this system, was able to maintain a stable dressing current and was unrelated to the change of dressing condition according to the variation of gap and oxide layer. Therefore, the optimum in-process electrolytic dressing system was constructed and the analysis of grinding mechanism with this system was studied. It is not possible to control according to the change of the dressing conditions in a general electrolytic dressing system. However, the optimum in-process electrolytic dressing system, which is controlled by optimum control software, is developed and has a good effect on maintaining regular dressing conditions. This system has an active control characteristic independent of the change of external conditions...