Influence of electrochemical potentials on the tribological behavior of silicon carbide and diamond-coated silicon carbide

Due to their high corrosion stability in combination with advantageous tribological performance, sintered silicon carbide ceramics are widely used in industrial applications. Both the corrosion stability and the tribological behavior can be affected by electrochemical processes. Tribological investigations were carried out using an electrochemical three electrode setup. The influence of electrochemical potentials on the friction and wear behavior of different sintered SiC materials in 1 M NaCl-solution was investigated to analyze the complex interplay between mechanical, chemical, and electrochemical interactions during tribo-corrosion. The results revealed that friction and wear of SiC were decreased under cathodic electrochemical polarization depending on the material composition. In addition, tribological tests at different electrochemical potentials showed that the coefficient of friction can be switched immediately. The results indicated that the tribological behavior is strongly affected by the increased double-layer repulsion due to the electrochemical potentials, which supports the hydrodynamic lubrication.