Material removal and wear mechanism in abrasive polishing of SiO2/SiC using molecular dynamics
VT Nguyen and TH Fang, CERAMICS INTERNATIONAL, 46, 21578-21595 (2020).
The effect of the sliding and rolling motions of the abrasive particle on the silicon carbide substrate covered by a thin film of silica atoms is investigated in this paper using molecular dynamics simulation. The influence of the sliding depth, sliding speed, rolling depth and rolling speed on the material removal and wear mechanism are surveyed. The results represent that increasing the sliding depth gives rise to higher forces, a higher temperature, a deeper groove, deeper subsurface damage (SSD) layer, and a higher amount of atoms erased. Improving the sliding velocity results in a higher fraction of atoms removed out of the pathway and a larger number of atoms erased. In the rolling mechanism, improving the depth and the rolling speed leads to the same effect as in the sliding mechanism but with a lower rate. Notably, the number of atoms erased in the rolling motion is greatly lower than the sliding one. In the ploughing regime, the silica film is effectively removed out of the SiC substrate, especially at a high sliding speed. The ploughing regime in the rolling motion requires a deeper depth to achieve, and the ploughing indications are weaker than the sliding motion. This report also considers both mechanical and chemical effects as some models with pure SiC workpiece or with different silica thickness are constructed and investigated. With the same removing conditions, the pure SiC sample suffers higher forces, a higher level of deformation and a larger number of atoms erased as compared to the sample covered by a silica thin film. The ploughing regime does not only require a sufficient penetration depth but also needs a suitable silica thickness to happen.
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