Tribological Characterization of NiAl Self-Lubricating Composites Containing V₂O₅ Nanowires

In order to improve the tribological properties of NiAl self-lubricating composites, V₂O₅ nanowires with average width of 39 nm were synthesized by hydrothermal method. Furthermore, NiAl self-lubricating composites containing V₂O₅ nanowires (NAV) were successfully fabricated using spark plasma sintering technique. The tribological characteristics and wear mechanisms of NAV were evaluated at different sliding speeds, counterface ball materials and elevated temperatures. The results revealed that the frictional properties of NAV improved slightly with adding V₂O₅ nanowires at room temperature if compared to NiAl self-lubricating composites without solid lubricant as investigated in previous studies, while the wear mechanisms of NAV change widely with the change of the counterface ball materials and sliding velocities. V₂O₅ nanowires showed a beneficial effect on tribological performance of NAV at high temperatures owing to the formation of the V₂O₅-enriched glaze film at temperatures above 700 °C, which acts as the lubricous and protective mask against the severe wear.