Hydrogenated carbon films (CHx) with different hydrogen content percentages have been examined. Drag tests on CHx coated disks, using 50 percent Al2O3/TiC sliders, with and without carbon coating on the slider air bearing surfaces (ABS), were conducted in an ultra high vacuum chamber equipped with a mass spectrometer. Mass fragments of lubricant released from the head disk interfaces were recorded in real time along with friction measurements. The results show that a higher hydrogen content in the carbon overcoat can improve wear durability by reducing the friction coefficient and affecting the chemical reactions between the sliders and the lubricant. A carbon overcoat on the slider ABS can protect Z-dol lubricant from catalytic reaction with the Al2O3 in the slider material. The wear durability at the head disk interface is controlled by combined mechanical and chemical factors, which are defined by the atomic structures of the contacting surfaces.

1.
Ager
Joel W.
,
1993
, “
Optical Characterization of Sputtered Carbon Films
,”
IEEE Transactions on Magnetics
, Vol.
29
, No.
1
, pp.
259
263
.
2.
D’Anna
E.
,
Leggieri
G.
,
Luches
A.
, and
Perrone
A.
,
1987
, “
Fragmentation Spectra and Appearance Potentials of Vacuum Pump Fluids Determined by Electron Impact Mass Spectrometry
,”
J. of Vac. Sci. Technol.
, Vol. A
5
(
6
), pp.
3436
3441
.
3.
Israelachvili
Jacob N.
,
1992
, “
Adhesion Forces Between Surfaces in Liquids and Condensable Vapours
,”
Surface Science Reports
, Vol.
14
, pp.
109
159
.
4.
Karis
T. E.
,
Novotny
V. J.
, and
Johnson
R. D.
,
1993
, “
Mechanical Scission of Perfluoropolyethers
,”
Journal of Polymer Science
, Vol.
50
, pp.
1357
1368
.
5.
Kasai
P. H.
,
Tang
W. T.
, and
Wheeler
P.
,
1991
a, “
Degradation of Perfluoropolyethers Catalyzed by Aluminum Oxide
,”
Applied Surface Science
, Vol.
51
, pp.
201
211
.
6.
Kasai
P. H.
, and
Wheeler
P.
,
1991
b, “
Degradation of Perfluoropolyethers Catalyzed by Aluminum Chloride
,”
Applied Surface Science
, Vol.
52
, N
1-2
, pp.
91
106
.
7.
Lee
J. K.
,
Smallen
M.
,
Enguro
J.
,
Lee
H. J.
, and
Chao
A.
,
1993
, “
The Effect of Chemical and Surface Properties of Hydrogenated Carbon Overcoats on the Tribological Performance of Rigid Magnetic Disks
,”
IEEE Transactions on Magnetics
, Vol.
29
, No.
1
, pp.
276
281
.
8.
Lin
J. L.
,
Bhatia
C. S.
, and
Yates
J. T.
,
1995
, “
Thermal and Electron— Stimulated Chemistry of Fomblin—Z-dol Lubricant on a Magnetic Disk
,”
J. of Vac. Sci. Technol.
, Vol. A
13
(
2
), pp.
163
168
.
9.
Novotny
V. J.
, and
Baldwinson
M. A.
,
1991
, “
Lubricant Dynamics in Sliding and Flying
,”
J. Appl. Phys.
,
70
(
10
), pp.
5467
5652
.
10.
Novotny, V. J., Pan, X., and Bhatia, C. S., 1994. “Tribochemistry at Lubricated Interfaces,” J. Vac. Sci. Technol., A, 12(5), Sept./Oct. 1994.
11.
Tamor
M. A.
,
Vassell
W. C.
, and
Carduner
K. R.
,
1991
, “
Atomic Constriant in Hydrogenated Diamond-Like Carbon
,”
Appl. Phys. Lett.
, Vol.
58
(6), 11, pp.
592
594
.
12.
Tsai
H.
, and
Bogy
D. B.
,
1987
, “
Critical Review Characterization of Diamondlike Carbon Films and Their Application as Overcoats on Thin Film Media for Magnetic Recording
,”
J. Vac. Sci. Technol.
, A
5
(
6
), Nov./Dec., 1987, pp.
3287
3312
.
13.
Vurens
G. H.
, and
Mate
C. M.
,
1992
a, “
The Thermal Stability of Perfluoropolyethers on Carbon Surfaces
,”
Applied Surface Science
, Vol.
59
, pp.
281
287
.
14.
Vurens, G. H., Zehringer, R., and Saperstein, D., 1992b, “The Decomposition Mechanism of Perfluoropolyether Lubricants During Wear,” Surface Science Investigations in Tribology, Chung, T-W, Homola, A. M., and Street, G. B., eds.
15.
Yun, X., Bogy, D. B., and Bhatia, C. S., 1996, “Wear of Hydrogenated Carbon Disks by Carbon Coated and Uncoated Al2O3/TiC Sliders in Ultra High Vacuum,” IEEE Transactions on Magnetics, Sept. 1996.
16.
Zehe, M. J., and Faut, O. D., 1989, “Acidic Attack of Perfluorinated Alkyl Ether Lubricant Molecules by Metal Oxide Surfaces,” NASA Technical Memorandum: 101962.
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