セラミックス研削時の仕上面下に進展するき裂の深さに対する解析的推定

抄録

This paper deals with the analytical approach to the depth of remaining surface cracks in ceramics ground by an orthogonal single grain. The analysis consists of the sequential treatment of the grain-work interference repeated during the grinding, the elastic/plastic stress fields in the work formed by the interference and the crack extension under the stress fields. The cracks extending from various interference positions above the surface being finished were evaluated by the depth of crack tip below the surface, considering their influence on the surface quality of the work. The maximum depth of the remaining cracks calculated was shown to be approximately consistent with those from grinding experiments for alumina ceramics and soda-lime glass over a wide range of grinding conditions (wheel depth of cut, work speed and radius of the grain tip). The maximum depth of remaining surface cracks increased with increasing wheel depth of cut until a certain value, beyond which it became constant. Increase in work speed and radius of the grain tip elongated the maximum remaining depth monotonically. These changes in the maximum depth of surface cracks with grinding conditions are due to their complex effects on the dimension of crack extension and the position of the grain-work interference.