Corrosion and Wear Behavior of Impregnated Graphite under Ceramic Pairing

The friction and corrosion characteristics of impregnated graphite in different media environments were studied by using scanning electron microscope and laser confocal microscope to respectively characterize the surface wear morphology, contact zone wear contour and wear volume. Analyzed the open circuit potential, polarization curve, electrochemical impedance map, and some key parameters related electrochemical impedance in deionized water and seawater, the friction and wear surface properties and mechanism of graphite impregnated paired with two kinds of ceramic dual balls were evaluated and analyzed. The results showed that the self-corrosion current density was lower, the capacitance arc was larger and phase angle was higher, the polarization resistance values were larger, when impregnated graphite was matched with ceramic ball Si₃N₄, and the impregnated graphite matched with ceramic ball Si₃N₄ exhibit a characteristic of better corrosion resistance and wear resistance. With the normal load increased, the open circuit potential showed a tendency to move in a negative direction, indicating that the corrosion resistance of graphite contact zone was enhanced. There was obvious furrow phenomenon on the surface of graphite in deionized water, and the wear mechanism was manifested as friction wear. The corrosion products and abrasive debris in the process of graphite wear and corrosion under seawater media formed a transfer film on the contact surface, and the contact surface morphology showed relatively smooth. During friction and corrosion process, the wear volume and dissipated energy in the friction process showed positively correlated with the increase of the normal load, while the wear rate showed negatively correlated with the increase of the normal load. The phenomenon of adhesion showed more obvious in seawater on the graphite contact surface, accompanied by abrasive wear and slight oxidation wear. The contact area in deionized water performed mainly abrasive wear, accompanied by slight adhesive wear and fatigue wear.