Experimental study on size effect of tool edge and subsurface damage of single crystal silicon in nano-cutting

Abstract

A method for fabricating a diamond tool with controllable edge radius was proposed. Using diamond tools with different edge radii at a low speed, nano-cutting tests were performed on single crystal silicon using a special instrument with SEM online observation. The chip morphology and deformation coefficient were analyzed to study the size effect of tool edge in the ductile-cut region. Electron back-scattered diffraction and laser micro-Raman spectroscopy were employed to detect subsurface damage in the machined silicon. The results indicated that the cutting-induced amorphous layer thickness is strongly dependent on the depth of cut and tool edge radius. In the beginning, the amorphous damage layer thickness decreases rapidly with the depth of cut, and then it increases gradually with the further increase in the depth of cut. The minimum amorphous damage can be obtained when the depth of cut is comparable to the tool edge radius.