Étude du phénomène électromagnétomécanochimique et du mécanisme de transfert dans les contacts glissants secs et lubrifiés bronze-acier et graphite-bronze.

Abstract

The tribological behavior of the bronze-steel and graphite-bronze couples was studied as a function of electromechanical parameters. To do this, a pin on cylinder tribometer was used. The tests were conducted in dry atmosphere, to determine the coefficient of friction, wear and temperature of the contact. In parallel with these experimental studies, a modeling study of a lubricated contact with a ferrofluid in the presence of magnetic field under imposed loading was made. On the other hand, in order to apprehend the evolution of the thermal behavior of the couple graphite-bronze (temperature at the interface), the experimental design method specifies the orthogonal row of Taguchi L27 was used. The discussion of the results obtained is based on observations and analyzes of the worn surfaces of the contact elements; as well as on the results obtained from the statistical methods used. In fact, analysis of the worn surface side of the samples has demonstrated the significant influence of the electric current on the degree of oxidation as well as on the growth rate of the oxidized layer, which governs the tribological behavior of the antagonists. In addition, other analyzes have revealed the surface quality of the bronze and steel disc. The modeling study of the contact lubricated with ferrofluid in the presence of magnetic field under imposed loading shows that the performances of the bearing are considerably modified when the magnetic effects are comparable to the hydrodynamic effects. In fact, the magnetic effect decreases with the increase of the applied load