Tribological performance of TiAl matrix composites containing silver and V2O5 nanowires at elevated temperatures

Abstract

TiAl alloys (TAs) are widely used in aircraft and automotive industries, but their poor wear resistance restrains further applications. In this paper, the tribological properties of TiAl matrix self-lubricating composites containing lubricants of varying amounts (0.5 wt%, 1.5 wt% and 2.5 wt%) of V₂O₅ nanowires (NWs) and 5 wt% silver against Si₃N₄ balls were investigated from room temperature to 600 °C under the same conditions of 20 N load per bearing section and 0.35 m s⁻¹ gliding speed. TiAl–5Ag–1.5V₂O₅ NWs (TB) exhibited excellent tribological properties over a wide temperature range. Moreover, at 450 °C, TB showed a lower friction coefficient of 0.19 and a lower wear rate of 1.87 × 10⁻⁴ mm³ N⁻¹ m⁻¹, which were attributed to a continuous lubricating film containing V₂O₅ NWs and silver on the friction surface. Furthermore, in the formed lubricant films, silver was used as a solid lubricant to provide good lubrication, while V₂O₅ NWs played the role of a support with high shear strength. The investigation indicated that V₂O₅ NWs and silver exhibited an excellent synergistic effect for improving the tribological properties of TB.