Ploughing friction and nanohardness dependent on the tip tilt in nano-scratch test for single crystal gold

Abstract

a b s t r a c tDifferent from macro-scale scratch, in nano-scale scratch test, the scratching tip is easily tilted, which may display a considerable change of the friction behavior. The ploughing friction and nanohardness dependent on the tip tilt in nano-scratch test for single crystal gold is studied in this paper by using molecular dynamics simulations. The results show that tilting forward (backward) to the scratch direction has a larger effect on the friction coefficient than the case of tilting laterally to the scratch direction. Scratch hardness is also sensitive to the tip tilting forward (backward), while it is insensitive to the tip tilting laterally. Moreover, the local plastic behaviors near tip (pile-up, plastic area, and dislocation evolution) are also dependent on the tip tilt, which may be a major contribution to the mechanism of the nano-scale wear.

Molecular Dynamics Study on Tip-Based Nanomachining: A Review

“…Unlike the macroscratching process where the water layer mainly plays role of lubrication and reduction of cutting force, the resistance of the water layer is dominant compared with the lubricating effect and the thicker water layer leads to larger total cutting forces [ 60 ]. Besides, the effect of tip inclination is also discussed by the analysis of hardness (normal force per atom) and friction coefficient [ 59 ]. The results show that the normal hardness is more sensitive in forward or backward direction compared and the effect of tip inclination laterally can be neglected.…”

“…Thus, the effect of the tip tilt should not be neglected. Liu et al chose tips with different inclination angles to investigate the effect of the tip inclination on the machining outcomes [ 59 ]. In addition, the tip wear is a key factor for the machining process, which has large influence on the machining quality.…”

Influence of Tool Shape on Surface Quality of Monocrystalline Nickel Nanofabrication

“…Some documents [ 14 , 15 ] also studied the influence of tool angle or shape on nanofabrication. However, most of the studies as mentioned above focused on qualitative trend analysis in one aspect of processing, such as the relationship between tool rake angle and shear force, and the relationship between tool radius and size effect.…”

Contact laws between nanoparticles: the elasticity of a nanopowder

“…how energy is dissipated from the relative motion of nano-interfaces). Both computational [18][19][20] and experimental 21,22 efforts are be- ing continuously devoted to understanding these interface effects at the nanoscale, with a special emphasis on the role of chemical bonds 23 and molecular adsorbates 24 down to the single ion scale 25 . Nevertheless, the experimental verification of contacts laws at the nano and sub-nanoscales remains very difficult due to deviatoric effects inherent to the destructive nature of the methods used.…”