Stress Analysis around Cutting Edge in Machinable Ceramics Cutting

摘要

It is possible that the machineable ceramics used in this experiment are subjected to external form cutting, drilling, and tapping by sintered carbide available on the market. The main materials of these ceramics are pottery stone. It was manufactured by a crystallization method. It was composed of borosilicate glass with uniformly distributed fluorphlogophites. The purpose of this study is to clarify the tool form to prevent cracks from remaining on machined surfaces extremely. The three-dimensional cutting experiment and the orthogonal cutting one by produced orthogonal cutting apparatus were carried out. And the relationship between surface roughness and rake angle was investigated by the three-dimensional cutting experiment. The cutting forces necessary for stress analysis were obtained from the experiments. The stress distribution acting on the front of tool edges was calculated by FEM. The relation between the progress of the crack generation and the stress distribution by stress analyses basing on plain strain problems was discussed. As a result, the surface roughness obtained the minimum at rake angle -15 deg approx -5 deg. In conclusion, it was shown that the tool form to obtain machined surfaces of good surface roughness was shown by cutting at a rake angles of -15 deg.