Wang Kaibo, Li Hao, Guo Yufeng
State Key Laboratory of Mechanics and Control of Mechanical Structures and MOE Key Laboratory for Intelligent Nano Materials and Devices, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Materials (Basel). 2021 Aug 20;14(16):4717. doi: 10.3390/ma14164717.
Friction anisotropy is one of the important friction behaviors for two-dimensional (2D) van der Waals (vdW) crystals. The effects of normal pressure and thickness on the interfacial friction anisotropy in few-layer graphene, -BN, and MoSe under constant normal force mode have been extensively investigated by first-principle calculations. The increase of normal pressure and layer number enhances the interfacial friction anisotropy for graphene and -BN but weakens that for MoSe. Such significant deviations in the interfacial friction anisotropy of few-layer graphene, -BN and MoSe can be mainly attributed to the opposite contributions of electron kinetic energies and electrostatic energies to the sliding energy barriers and different interlayer charge exchanges. Our results deepen the understanding of the influence of external loading and thickness on the friction properties of 2D vdW crystals.
摩擦各向异性是二维范德华（vdW）晶体的重要摩擦行为之一。通过第一性原理计算，已广泛研究了在恒定法向力模式下，法向压力和厚度对少层石墨烯、氮化硼和二硒化钼界面摩擦各向异性的影响。法向压力和层数的增加增强了石墨烯和氮化硼的界面摩擦各向异性，但减弱了二硒化钼的界面摩擦各向异性。少层石墨烯、氮化硼和二硒化钼界面摩擦各向异性的这种显著偏差，主要可归因于电子动能和静电能对滑动能垒的相反贡献以及不同的层间电荷交换。我们的结果加深了对外部载荷和厚度对二维vdW晶体摩擦性能影响的理解。
