Abstract TLK (Terrace-Ledge-Kink) structure such as surface steps is often found on the surface of SiC materials. Removal behavior of SiC substrates with TLK structure has not been studied in a fixed abrasive polishing under nano-abrasion conditions. In this paper, the effect of TLK structure on the abrasion temperature, stress, and structural transition of SiC substrates during the nano-abrading process is pursued by molecular dynamics (MD) simulation. The results show that the average stress and temperature decrease with the increase of ledge numbers in the TLK structure. It is found that crystalline-to-amorphous (C–A) phase transition occurs. The high-density amorphorization of SiC is induced by a high shear stress, which transforms to low-density amorphous SiC with the release of shear stress. Furthermore, unlike previous reports, the pressure-induced 6-fold coordinated structure in 3C–SiC in this study, however, does not possess a high-pressured phase transition (HPPT) to rocksalt structure; instead, a disordered structure is found. The ductile domain removal goes through two stages: first through the dislocation nucleation and propagation at the initial abrading stage and is then followed by the plastic flow of the amorphous atoms after sliding over the ledge. The presence of TLK structures benefits the plastic deformation of the SiC substrate.

中文翻译：

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具有 TLK 结构的 3C-SiC 在纳米研磨过程中的应力诱导结构相变

摘要 碳化硅材料表面常出现表面台阶等TLK（Terrace-Ledge-Kink）结构。具有 TLK 结构的 SiC 衬底的去除行为尚未在纳米研磨条件下的固定磨料抛光中进行研究。在本文中，TLK 结构对纳米研磨过程中 SiC 衬底的磨损温度、应力和结构转变的影响是通过分子动力学 (MD) 模拟来研究的。结果表明，随着TLK结构中壁架数量的增加，平均应力和温度降低。发现发生结晶到非晶（C-A）相变。SiC 的高密度非晶化是由高剪切应力引起的，随着剪切应力的释放，SiC 转变为低密度非晶 SiC。此外，与之前的报道不同，然而，本研究中 3C-SiC 中压力诱导的 6 重配位结构不具有向岩盐结构的高压相变（HPPT）；相反，发现了无序结构。韧性域的去除经历两个阶段：首先通过初始研磨阶段的位错成核和传播，然后是无定形原子滑过壁架后的塑性流动。TLK 结构的存在有利于 SiC 衬底的塑性变形。首先通过初始研磨阶段的位错成核和传播，然后是无定形原子滑过壁架后的塑性流动。TLK 结构的存在有利于 SiC 衬底的塑性变形。首先通过初始研磨阶段的位错成核和传播，然后是无定形原子滑过壁架后的塑性流动。TLK 结构的存在有利于 SiC 衬底的塑性变形。