Ning Xiang, Huang Jiawen, Zhang Rumeng, Liu Dongliang, Li Jiao, Wu Nanxing
School of Mechanical and Electronic Engineering, Jingdezhen Ceramic University, Jingdezhen, 333403, Jiangxi, China.
National Engineering Research Center for Domestic & Building Ceramics, Jingdezhen, 333403, Jiangxi, China.
Sci Rep. 2024 Aug 6;14(1):18183. doi: 10.1038/s41598-024-68933-3.
To study the effect of polycrystalline 3C-SiC rough friction surface on the mechanism of subsurface brittleness during nanocrystalline grinding. Initial grinding models of polycrystalline 3C-SiC and diamond abrasive grains on rough friction surfaces are developed using molecular dynamics methods and the Voronoi method for constructing polycrystalline abrasive grains. The processing mechanism of 3C-SiC is analyzed by post-processing methods such as dislocation defect analysis, atomic arrangement analysis and stress analysis. At 2.6 nm, "stress concentration" occurs between the abrasive particles and the workpiece, forming irregular force shapes. The larger the grain size, the smaller the crystal hardness, the greater the possibility of crystal fracture, and it is obvious in the crystal of larger grains. At 8 nm, the crystal breaks and creates vacancies. The roughness of the polycrystalline 3C-SiC friction surface and the cross-cutting mechanism between grains with grain boundaries are found to be effective in ameliorating the damage in the subsurface layer.
研究多晶3C-SiC粗糙摩擦表面对纳米晶磨削过程中亚表面脆性机制的影响。采用分子动力学方法和用于构建多晶磨粒的Voronoi方法，建立了粗糙摩擦表面上多晶3C-SiC和金刚石磨粒的初始磨削模型。通过位错缺陷分析、原子排列分析和应力分析等后处理方法，分析了3C-SiC的加工机理。在2.6nm时，磨粒与工件之间出现“应力集中”，形成不规则的力形状。晶粒尺寸越大，晶体硬度越小，晶体断裂的可能性越大，在较大晶粒的晶体中表现明显。在8nm时，晶体断裂并产生空位。发现多晶3C-SiC摩擦表面的粗糙度以及晶界处晶粒之间的交叉切割机制对减轻亚表层损伤有效。
