SURFACE MODIFICATIONS OF A NONFERROMAGNETIC COPPER FERROMAGNETIC STEEL XC48 COUPLE IN MAGNETIZED SLIDING CONTACT

The effect of a magnetic field on the wear of steel/copper couple rubb ing systems has been investigated in air. The applied magnetic field i s normal to the sliding contact surface. Experiments have shown that t he wear rates of pin and disc and microhardness of the sliding surface s of both ferromagnetic and non-ferromagnetic materials increase with application of a magnetic field. The applied magnetic field significan tly influences the mechanical properties of the metals and modifies th e surface hardness of materials by magnetoplastic effect. The surface of the materials becomes harder under the simultaneous effects of the normal load and the sliding speed in the presence of the magnetic fiel d. A model of dislocation flow enhanced by the presence of a magnetic field explains the increase of dislocation density in sliding surfaces and particularly in the junctions of asperities submitted to high str esses; the microhardness subsequently increases. Brittleness of harder asperities induces the sliding wear behavior of magnetized materials. The applied magnetic field also enhances and activates the surface ox idation. The size of the oxide wear particles is thinned in sliding co ntact. Experimental results from the sliding surface modifications, wi th and without magnetic field (wear rate, microhardness), are presente d. A simple model to explain the observed phenomenon is proposed.