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 11̄0 and 01̄0 directions, deep line defects consisting of microcracks and dislocation groups occurred even when the surface was "ductile"-cut; while for the 1283090 direction, the damage depth was reduced by a factor of five.