Crystallographic effect on subsurface damage formation in silicon microcutting

Nanoprecision plunge cutting tests were carried out on single-crystal silicon (0 0 1) samples along various directions at different tool rake angles, and subsurface damage was characterized by cross-sectional transmission electron microscopy and laser micro-Raman spectroscopy. It was found that amorphization, poly-crystallization, dislocation and internal microcracking occurred and these material responses depended strongly on the cutting direction. When cutting in the [11¯0] and [01¯0] directions, deep line defects consisting of microcracks and dislocation groups occurred even when the surface was “ductile”-cut; while for the [128309¯0] direction, the damage depth was reduced by a factor of five.