ISSN:
1573-2711
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract This paper summarizes the results of friction measurements made between two Cu(111) surfaces using an ultrahigh vacuum (UHV) tribometer. Both sample surfaces were modified by the adsorption of either atoms (sulfur, chlorine or iodine) or molecules(ethanol, trifluoroethanol, butanol, or heptafluorobutanol). The coverages of adsorbed atoms ranged from zero to the saturation coverage for the given atomic species while for the molecular adsorbates the coverages ranged from zero to tens of monolayers.The friction coefficients were then measured as a function of coverage. The Cu(111) surfaces were effectively unlubricated with adsorbate coverages of less than or equal to one monolayer, exhibiting “stick-slip” behavior during sliding and high static friction coefficients. This behavior was observed for all adsorbates studied. A transition to lower friction coefficients was observed at coverages exceeding one monolayer. The friction coefficient decreased monotonically with increasing coverage, reaching a limiting value at coverages of several multilayers.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1019142919192
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