Problems in nanomechanics often need to combine mechanical approaches together with methods of physics and chemistry that are outside of the traditional mechanics scope. Recent experimental studies of dry sliding between two hydrogenated DLC (diamond-like carbon) coated counterparts in low oxygen environment showed that adsorbates have considerable influence on friction and the friction coefficient increases with the increasing of the time interval between contacts. The observed friction phenomena are assumed caused by a reaction between the adsorbate and carbon atoms of the coatings, and when the slider passes a point on the track, it removes mechanically some adsorbate from the surface. The mechanical action leads to reexposure of the surface to gases in the environment. This paper focuses on physical and tribochemical processes that occur in sliding contact between the DLC coated slider and the counterpart. We develop further our recently presented model of the process and assume that there is a transient short-life high temperature field at the vicinities of contacting protuberances that may cause various transformations of the surface. In particular, the sp3 phase of DLC films may transform to graphite-like sp2 carbon. Our model does not depend directly on the assumption that the adsorbate is oxygen. However, due to the prevalence of oxygen in atmospheric gas it is assumed that the adsorbate is oxygen in the model presented. We suppose that first an oxygen molecule becomes physically adsorbed to the surface and then due to rubbing the molecule dissociates into two chemically active oxygen atoms. This process leads to chemisorbtion between the carbon atoms of the coating and the “sticky” oxygen atoms. The latter atoms can interact with the counterpart. Our modeling established a direct connection between this kind of molecular friction and gradual wear. In particular, it is shown that the initial roughness of the DLC surface may have a considerable influence on the probability of breaking bonds during mechanical removal of adsorbate. Ab initio calculations of the bond dissociation energies between carbon atoms and carbon-oxygen atoms were performed using GAUSSIAN98 at the Møller-Plesset level of model chemistry. The bond dissociation energy found for the carbon-carbon bonds is 523kJmol, while for the carbon-oxygen bonds it is 1447kJmol. It is assumed that carbon wear particles will not be formed during gradual degradation since the coating carbon molecules are dissolved within the environment gases. The model helps to explain how microscopic processes, such as the breaking and forming of interatomic bonds, may affect macroscopic phenomena, such as friction and wear.

1.
Krim
,
J.
, 2002, “
Friction at Macroscopic and Microscopic Length Scales
,”
Am. J. Phys.
0002-9505,
70
, pp.
890
897
.
2.
Frauenheim
,
T.
,
Jungnickel
,
G.
,
Porezag
,
D.
,
Sternberg
,
M.
, and
Köhler
,
T.
, 1997, “
Atomistic Simulations of Carbon Systems Using a Density-Functional-Based Molecular-Dynamics Method
,”
The Physics of Diamond
,
IOS Press
, Amsterdam, pp.
105
132
.
3.
Erdemir
,
A.
, 2001, “
The Role of Hydrogen in Tribological Properties of Diamond-Like Carbon Films
,”
Surf. Coat. Technol.
0257-8972,
146
, pp.
292
297
.
4.
Kragelsky
,
I. V.
, and
Shchedrov
,
V. S.
, 1956,
Development of the Science about Friction
,
USSR Academy of Sciences Press
, Moscow.
5.
Amontons
,
G.
, 1699, “
De la Résistance Causée Dans les Machines
,” Mém. de l’Académie Royale A, pp.
275
282
.
6.
Kotelnikov
,
S. K.
, 1774,
A Book Containing the Doctrine on Equilibrium and Motion of Bodies
,
Naval Noble College
,
Saint-Petersburg
.
7.
Blau
,
P. J.
, 2001, “
The Significance and Use of the Friction Coefficient
,”
Tribol. Int.
0301-679X,
34
, pp.
585
591
.
8.
Coulomb
,
C. A.
, 1821,
Theorie des Machines Simples, en Ayant égard au Frottement de Leurs Parties et à la Roideur des Cordages
,
Bachelier
, Paris.
9.
Tomlinson
,
G. A.
, 1929, “
A Molecular Theory of Friction
,”
Philos. Mag.
0031-8086 Ser. 7,
7
, pp.
905
939
.
10.
Derjaguin
,
B.
, 1934, “
Molekulartheorie der äußeren Reibung
,”
Z. Phys.
0044-3328,
88
, pp.
661
164
.
11.
Mikhin
,
N. M.
, 1978, “
Calculation of Coefficients of External Friction and Preliminary Displacement
,”
Friction, Wear and Lubrication
, I. V. Kragelsky and V. V. Alisin, eds.,
Mir Publishers
, Moscow,
1
, pp.
54
101
.
12.
Akhmatov
,
A. S.
, 1963,
Molecular Physics of Boundary Friction
,
GIFML
, Moscow. (English Translation, 1966, Israel Program for Sc. Translations, Jerusalem).
13.
Zhuravlev
,
V. A.
, 1940, “
On Question of Theoretical Justification of the Amontons-Coulomb Law for Friction of Unlubricated Surfaces
,”
Zh. Tekh. Fiz.
0044-4642,
10
, pp.
1447
1452
.
14.
Greenwood
,
J. A.
, and
Williamson
,
J. B. P.
, 1966, “
Contact of Nominally Flat Surfaces
,”
Proc. R. Soc. London, Ser. A
1364-5021,
295
, pp.
300
319
.
15.
Heinicke
,
G.
, 1984,
Tribochemistry
,
Academie-Verlag
, Berlin.
16.
Quinn
,
T. F. J.
, 1991,
Physical Analysis for Tribology
,
Cambridge University Press
, Cambridge.
17.
Goryacheva
,
I. G.
, 1998,
Contact Mechanics in Tribology
,
Kluwer Academic Publishers
, Dordrecht.
18.
Chung
,
Y.-W.
, 2001,
Practical Guide to Surface Science and Spectroscopy
,
Academic Press
, San Diego.
19.
He
,
G.
,
Müser
,
M. H.
, and
Robbins
,
M. O.
, 1999, “
Adsorbed Layers and the Origin of Static Friction
,”
Science
0036-8075,
284
, pp.
1650
1652
.
20.
Marchon
,
B.
,
Heiman
,
N.
, and
Khan
,
M. R.
, 1990, “
Evidence for Tribochemical Wear of Amorphous Carbon Thin Films
,”
J. Exp. Mar. Biol. Ecol.
0022-0981,
26
, pp.
168
170
.
21.
Zaïdi
,
H.
,
Paulmier
,
D.
, and
Lepage
,
J.
, 1990, “
The Influence of the Environment on the Friction and Wear of Graphitic Carbons. II. Gas Coverage of Wear Debris
,”
Appl. Surf. Sci.
0169-4332,
44
, pp.
221
233
.
22.
Dugger
,
M. T.
,
Wahl
,
K. J.
,
Chung
,
Y.-W.
,
Bhushan
,
B.
, and
Rothschild
,
W.
, 1991, “
An Investigation of Environmental Effects on the Wear and Surface Composition of Thin Film Magnetic Discs
,”Society of Tribologists and Lubrication Engineers, Park Ridge, IL,
SP31
, pp.
43
53
.
23.
Heimberg
,
J. A.
,
Wahl
,
K. J.
,
Singer
,
I. L.
, and
Erdemir
,
A.
, 2001, “
Superlow Friction Behavior of Diamond-Like Carbon Coatings: Time and Speed Effects
,”
Appl. Phys. Lett.
0003-6951,
78
, pp.
2449
2451
.
24.
McGuiggan
,
P. M.
,
Hsu
,
S. M.
,
Fong
,
W.
,
Bogy
,
D.
, and
Bhatia
,
C. S.
, 2002, “
Friction Measurements of Ultra-Thin Carbon Overcoats in Air
,”
J. Tribol.
0742-4787,
124
, pp.
239
244
.
25.
Adamson
,
A. W.
, 1990,
Physical Chemistry of Surfaces
,
Wiley
, New York.
26.
Erdemir
,
A.
,
Eryilmaz
,
O. L.
, and
Fenske
,
G. J.
, 2000, “
Synthesis of Diamond-Like Carbon Films with Superlow Friction and Wear Properties
,”
J. Vac. Sci. Technol. A
0734-2101,
18
, pp.
1987
1992
.
27.
Sanchez-Lopez
,
J. C.
,
Erdemir
,
A.
,
Donnet
,
C.
, and
Rojas
,
T. C.
, 2003, “
Friction-Induced Structural Transformations of Diamond-Like Carbon Coatings Under Various Atmospheres
,”
Surf. Coat. Technol.
0257-8972,
163
, pp.
444
450
.
28.
Borodich
,
F. M.
, and
Keer
,
L. M.
, 2004, “
Modeling Effects of Gas Adsorption and Removal on Friction During Sliding Along Diamond-Like Carbon Films
,”
Thin Solid Films
0040-6090 (in press).
29.
Pykhtin
,
M. V.
,
Lewis
,
S. P.
,
Mele
,
E. J.
, and
Rappe
,
A. M.
, 1998, “
Collective Motion and Structural Order in Adsorbate Vibrational Dynamics
,”
Phys. Rev. Lett.
0031-9007,
81
, pp.
5940
5943
.
30.
Ramirez
,
A. G.
, and
Sinclair
,
R.
, 1999, “
Wear-Induced Modifications of Amorphous Carbon in the Presence of Magnetic Media
,”
J. Appl. Phys.
0021-8979,
85
, pp.
5597
5599
.
31.
Jahanmir
,
S.
,
Deckman
,
D. E.
,
Ives
,
L. K.
,
Feldman
,
A.
, and
Farabaugh
,
E.
, 1989, “
Tribological Characteristics of Synthesized Diamond Films on Silicon-Carbide
,”
Wear
0043-1648,
133
, pp.
73
81
.
32.
Frisch
,
M. J.
,
Trucks
,
G. W.
,
Schlegel
,
H. B.
,
Scuseria
,
G. E.
,
Robb
,
M. A.
,
Cheeseman
,
J. R.
,
Zakrzewski
,
V. G.
,
Montgomery
, Jr.,
J. A.
,
Stratmann
,
R. E.
,
Burant
,
J. C.
,
Dapprich
,
S.
,
Millam
,
J. M.
,
Daniels
,
A. D.
,
Kudin
,
K. N.
,
Strain
,
M. C.
,
Farkas
,
O.
,
Tomasi
,
J.
,
Barone
,
V.
,
Cossi
,
M.
,
Cammi
,
R.
,
Mennucci
,
B.
,
Pomelli
,
C.
,
Adamo
,
C.
,
Clifford
,
S.
,
Ochterski
,
J.
,
Petersson
,
G. A.
,
Ayala
,
P. Y.
,
Cui
,
Q.
,
Morokuma
,
K.
,
Rega
,
N.
,
Salvador
,
P.
,
Dannenberg
,
J. J.
,
Malick
,
D. K.
,
Rabuck
,
A. D.
,
Raghavachari
,
K.
,
Foresman
,
J. B.
,
Cioslowski
,
J.
,
Ortiz
,
J. V.
,
Baboul
,
A. G.
,
Stefanov
,
B. B.
,
Liu
,
G.
,
Liashenko
,
A.
,
Piskorz
,
P.
,
Komaromi
,
I.
,
Gomperts
,
R.
,
Martin
,
R. L.
,
Fox
,
D. J.
,
Keith
,
T.
,
Al-Laham
,
M. A.
,
Peng
,
C. Y.
,
Nanayakkara
,
A.
,
Challacombe
,
M.
,
Gill
,
P. M. W.
,
Johnson
,
B.
,
Chen
,
W.
,
Wong
,
M. W.
,
Andres
,
J. L.
,
Gonzalez
,
C.
,
Head-Gordon
,
M.
,
Replogle
,
E. S.
, and
Pople
,
J. A.
, 2001,
Gaussian 98
(Revision A.11.2),
Gaussian, Inc.
, Pittsburgh, PA, USA.
33.
Møller
,
C.
, and
Plesset
,
M. S.
, 1934, “
Note on an Approximation Treatment for Many-Electron Systems
,”
Phys. Rev.
0031-899X,
46
, pp.
618
622
.
34.
Weast
,
R. C.
, 1980,
CRC Handbook of Chemistry and Physics
, 60th ed.,
CRC Press
, Boca Raton, FL.
35.
Donnet
,
C.
,
Le Mogne
,
T.
,
Ponsonnet
,
L.
,
Belin
,
M.
,
Grill
,
A.
,
Patel
,
V.
, and
Jahnes
,
C.
, 1998, “
The Respective Role of Oxygen and Water Vapour on the Tribology of Hydrogenated Diamond-Like Carbon Coatings
,”
Tribol. Lett.
1023-8883,
4
, pp.
259
265
.
36.
Roginsky
,
S. Z.
, 1949,
Adsorption and Catalysis on Heterogeneous Surfaces
, Akademia Nauk USSR, Moscow.
37.
Valenzuela-Calahorro
,
C.
,
Navarrete-Guijosa
,
A.
,
Stitou
,
M.
, and
Cuerda-Correa
,
E. M.
, 2003, “
Retention of Progesterone by Four Carbonaceous Materials: Study of the Adsorption Kinetics
,”
Colloids Surf., A
0927-7757
224
, pp.
135
147
.
38.
Elovich
,
S. Y.
, and
Zhabrova
,
G. M.
, 1939,
Zh. Fiz. Khim.
0044-4537,
13
, pp.
1775
1786
(
English Abstract
, 1941,
Chem. Abstr.
0009-2258
35
, pp.
373
).
39.
Dickrell
,
P. L.
,
Sawyer
,
W. G.
, and
Erdemir
,
A.
, 2004, “
Fractional Coverage Model for the Adsorption and Removal of Gas Species and Application to Superlow Friction Diamond-Like Carbon
,”
J. Tribol.
0742-4787,
126
, pp.
615
619
.
40.
Langmuir
,
I.
, 1916, “
The Constitution and Fundamental Properties of Solids and Liquids. Part I. Solids
,”
J. Am. Chem. Soc.
0002-7863,
38
, pp.
2221
2295
.
41.
Zhang
,
S. L.
,
Wagner
,
G.
,
Medyanik
,
S. N.
,
Liu
,
W. K.
,
Yu
,
Y. H.
, and
Chung
,
Y.-W.
, 2004, “
Experimental and Molecular Dynamics Simulation Studies of Friction Behavior of Hydrogenated Carbon Films
,”
Surf. Coat. Technol.
0257-8972,
177
, pp.
818
823
.
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