Effect of crystalline orientation of a diamond tool on the machined surface in ductile mode cutting of silicon

Abstract

In nanoscale ductile mode cutting of monocrystalline silicon with single-crystal diamond tools, it was observed that under certain crystalline orientations of the diamond tool, such as with {110} or {100} for the tool rake face, good integrity of the machined surface could be generated. However, when the tool had the {111} orientation for the rake face, the machined surface was fractured. In the present study, the crystalline behaviour of the monocrystalline diamond tool in nanoscale cutting of monocrystalline silicon and its effect on the machined surface were experimentally investigated using the {100}, {110}, and {111} orientations for the rake faces of single-crystal diamond tools. The results showed that when the rake face orientation of the diamond cutter was changed from {100} or {110} to {111}, the chip formation mode changed from ductile to brittle. The cause of such behaviour of single-crystal diamond tools was found to be the different values of the Young's modulus of single-crystal diamond in the {100}, {110}, and {111} orientations.