M. El Mansori et al., Lubrication mechanisms of a sliding contact by simultaneous action of electric current and magnetic field, WEAR, 229(2), 1999, pp. 1011-1016
This paper reports the friction tests results performed in open air of 20-3
0% relative humidity (RH) at room temperature of steel/graphite in sliding
contact crossed by a DC electric current and submitted to a DC magnetic fie
ld. Magnetic field is applied normally to the sliding contact area. As have
been elucidated by numerous friction tests in various experimental conditi
ons, it was shown that the simultaneous effects of an electric current and
that of a magnetic field decrease the friction coefficient of the couple an
d enhance the slope of the high friction-low friction state transition acco
rding to their intensities. This effect, similar to the lubrication of the
contact, is attributed to the oxidation of the steel material, leading also
to a reduction of the real contact area and to a carbon transfer on the st
eel friction track. Facilitation of this carbon transfer by the change of m
agnetic properties of the graphite friction track and by the reorientation
process due to the magneto-mechanical effects, explains the low friction st
ate and wear rate characteristic in the case of high electric-magnetic fiel
d intensity and high contact pressure. (C) 1999 Published by Elsevier Scien
ce S.A. All rights reserved.