STUDY OF MAGNETIZED OR ELECTRICAL SLIDING CONTACT OF A STEEL XC48 GRAPHITE COUPLE/

The effects of a d.c magnetic field or an electric current on the fric tional behaviour of steel XC48/graphite were investigated. Experimenta l results are as follows. (1) At ambient atmosphere, both a magnetic f ield present in a tribocontact and an electric current through the sli ding contact decrease the mean value of friction coefficient and decre ase its fluctuations also. Electric current enhances sliding surface o xidation according to surface polarity. A magnetic field may increase the pressure of molecular oxygen around the tribocontact and increase the sliding surface oxidation. An oxide layer on the sliding surface l eads to a low friction state. (2) Under an inert gas such as argon the application of a magnetic field or the passage of an electric current through the contact leads to an increase of the friction coefficient. This is due to a transfer of fine particles of iron from the steel to the graphite which leads to the formation of metallic junctions durin g friction. (C) 1997 Elsevier Science S.A.