Investigations on brittle-ductile cutting transition and crack formation in diamond cutting of mono-crystalline silicon

In this paper, the load-displacement curve of mono-crystalline silicon is first obtained by serials of nano-indentation experiments. Then, the material constitutive model of mono-crystalline silicon is developed. On this basis, a finite element method (FEM) model for the cutting process of mono-crystalline silicon is built and the critical brittle-ductile transition thickness is obtained by cutting simulations. Moreover, the fly-cut experiments on the ultra-precision diamond machine are performed to analyze the effect of cutting speeds on the brittle-ductile transition thicknesses, which are also used to validate the simulation results. Finally, by using extended element method, the mechanism of initiation and propagation of crack in the cutting process of mono-crystal silicon is studied and the effects of cut-induced cracks on the brittle-ductile transition of mono-crystalline silicon are deeply understood.