Influence of magnetic field on surface modification and the friction behavior of sliding couple aluminium/XC 48 steel

We have studied the surface modification and tribological behavior of the p aramagnetic aluminum alloy/ferromagnetic steel XC 48 sliding couple in the presence and absence of a d.c. magnetic field. Experiments were conducted o n pin/disc tribometer in ambient atmosphere under an applied normal load P = 3.4 N and a sliding speed nu = 0.67 m s(-1). The magnetic field was appli ed to the aluminum pin and remained constant during the test. Our experimen tal results show that the presence of a magnetic field around the tribocont act modifies the mechanical properties of the contact surfaces and their fr iction behavior. The modifications induced in contact surfaces and subsurfa ces of aluminum and steel by a magnetic field of H = 4500 A m(-1) after sli ding for 1 h are analyzed by Vickers microhardness, scanning electron micro scopy and energy dispersive spectroscopy (EDS) analysis. The microhardness gradient in the pin is about 12 H-v mu m(-1) in a thin layer of 30 mu m of material, and the mirohardness gradient in the disc is about 9.5 H-v mu m(- 1) in 20 mu m of the material depth. The oxygen consumed by the magnetized sliding surfaces increases by a factor of 4. The friction coefficient becom es more stable and decreases from mu = 0.55 to 0.45. The wear rates of both the pin and the disc are increased. (C) 1999 Elsevier Science S.A. All rig hts reserved.