Study on the transformation and control mechanism of amorphous damage during the grinding process of monocrystalline silicon considering grain shapes by MD method

To address the debate surrounding the stress criterion for a-Si transformation during the scratching process caused by the particular grain, atomic-scale single grain scratching MD models for monocrystalline silicon considering grain shapes are developed. The simulation results show that the critical octahedral shear stress (10.5 GPa) for a-Si transformation remains stable across different grains, while the critical hydrostatic pressure (−5.5 ~ −7.5 GPa) fluctuates greatly. Furthermore, the a-Si transformation is mainly due to the extrusion effect, supplemented by the shear effect of grain. Finally, conical grains are not recommended due to the larger SSD depth compared to spherical and truncated octahedral grains. This study offers a theoretical basis for reducing amorphous damage during the ultra-precision grinding processing of monocrystalline silicon.