Chemical effects on the sliding friction of Ag and Au(111)

Abstract

Abstract:We have investigated the sliding friction behavior of metallic couples with different enthalpy of mixing or reaction by friction force microscopy. Comparing the friction behavior of miscible and immiscible couples we find that in the first case friction is governed by adhesion while the shear strength is low (τ = 3-6 MPa). In the latter case of immiscible couples, adhesion is found to be low and the shear strength is large (τ ≈ 70 MPa). Statistical analysis of atomic stick-slip images recorded on an Au(111) surface with tips of different affinities with gold allows for a deeper understanding of our results. The periodicity of atomic stick-slip images corresponds to the interatomic distance of gold for immiscible counter-bodies. In contrast, for a reactive couple the periodicity of atomic stick-slip significantly differs from the gold interatomic distance and may correspond to the structural length of an ordered intermediate phase at the tip-surface interface.

Investigation on the role of interfacial water on the tribology between graphite and metals

“…The obtained value for the shear strength between Au and HOPG was comparable with the previously reported value for an Au tip sliding on an Au(111) surface, where we found s ¼ 24.21 MPa. 9 The friction force hF f i value averaged over the whole range of normal force values was found to be high for larger adhesion forces F ad , i.e. hF f i Au ¼ 0.62 AE 0.07 nN and F ad,Au ¼ À1.23 AE 0.11 nN and hF f i Pt ¼ 5.73 AE 1.19 nN and F ad,Pt ¼ À9.57 AE 0.21 nN.…”

Experimental Studies of Nanometer-Scaled Single-Asperity Contacts with Metal Surfaces

“…[3,4], where almost no frictional energy dissipation was measured. In this load regime also, the authors recently showed how the shear strength of such junctions can be tuned by changing the metallurgical affinity between the contact materials [7]. Also, nanoscale wear experiments by AFM demonstrated the determinant role of plastic deformation mechanisms [8,9].…”

“…In Refs. [6,7], friction between Au islands and graphite was studied. AF 2=3 n dependence of the friction force on gold islands measured in ambient conditions was observed, where F n is the normal force [6].…”

How Good Are the Performances of Graphene and Boron Nitride Against the Wear of Copper?

“…Specifically, the lubricating effect of graphene is understood as arising from its chemical inertness and large in-plane stiffness [ 15 ]. In contrast to metals where the single nanoscale asperity sliding contact is governed by the formation of adhesive junctions and their shearing, the leading mechanism of wear-less friction of graphene has been identified as puckering [ 16 , 17 , 18 ]. The nanoscale wear protection of graphene grown on Pt (111) has been simulated and experimentally verified in Reference [ 19 ].…”