Ductile-regime turning mechanism of single-crystal silicon

Diamond turning of single-crystal silicon was carried out along all the crystallographic directions on the (001) and (111) planes at depths of cut of 100 nm and 1 mu m, and then the mechanism involved in ductile-regime turning was studied. Pitting damage occurred along certain specific crystallographic orientations, The crystallographic orientation dependence of the surface features also changed with the depth of cut because of the difference in material removal mechanism between plastic deformation and brittle fracture. Transmission electron microscopy characterizations of the {111}[110] slip systems activated by fuming revealed that the orientation dependence of the surface features was closely related to the ease with which slip deformation occurred. To predict the surface features fumed along each crystallographic orientation, we proposed the slip orientation factor, which was determined from the Schmid factor, and demonstrated that it was useful for fuming in the critical regime between ductile and brittle. Our slip model, based on the slip orientation factor, describes the ductile-regime turning mechanism well.