Development of a model for precision contour grinding of brittle materials

Abstract

A graphical computer model of the chip geometry resulting from a three-dimensional grinding operation was developed for use in relating the critical depth data obtained from the one-dimensional plunge-grinding technique. This model predicts the resulting surface finish and calculates the theoretical roughness and the final chip geometry for a precision grinding operation. The model is based on euclidean geometry at the intersection of the surfaces of two solid objects. This model was programmed to calculate the remaining surface height as the wheel progresses across the part. The output of the surface profile for successive cuts can be subtracted to illustrate the shape of the chip removed for each revolution of the grinding wheel. Chip geometry as influenced by depth of cut, feed rate, and tool shape was shown to be an important parameter in diamond turning of brittle materials. Similar relationships are developed for the additional geometric complexities of a precision grinding operation. The theoretical surface features are then compared with the actual features generated by grinding brittle materials.