Atomic-scale study of vacancy defects in SiC affecting on removal mechanisms during nano-abrasion process. (May 2020)

• Record Type: Journal Article
• Authors: Zhou, Piao; Sun, Tao; Shi, Xunda; Li, Jun; Zhu, Yongwei; Wang, Zikun
• Is Part Of: Tribology international. Volume 145(2020)
• Publication Date: 2020-05
• Subjects: Molecular dynamic simulation -- SiC removal -- Vacancy defect -- Abrasive wear; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2019.106136
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: The mechanical properties of mono-crystalline SiC with vacancy defects in fixed abrasive polishing processes are not well known at the nanometric scale. In the molecular dynamic (MD) simulation, the removal mechanism of mono-crystalline SiC substrates with vacancy defects is investigated. So is the wear mechanism of diamond abrasives explored. The simulation result reveals that the increase of vacancy defects in SiC substrates leads to reduced von Mises Stress, however, to increased temperature of SiC substrates during nano-abrading process. More vacancy defects are found to lead higher removal efficiency and less subsurface damage on SiC substrates. Furthermore, the diamond abrasives are worn out through a combination of thermo-chemical wear, graphitization wear and abrasive wear in the simulation. Highlights: The influence of vacancy concentration on removal mechanisms of SiC substrates is explored by MD simulation in nano-abrasion. The wear mechanism of diamond abrasive is studied. The presence of vacancy defects in SiC substrates reduces the von Mises Stress and increses the abrading temperature. Removal efficiency increases and subsurface damage depth decreases, respectively, with increasing the vacancy concentration in the machining area of SiC substrates.