固体润滑国家重点实验室（LSL）知识库

Silver vanadate (AgVO₃) nanowires were synthesized by hydrothermal method and self-lubricating NiAl/Mo-AgVO₃ composites were fabricated by powder metallurgy technique. The composition and microstructure of NiAl/Mo-based composites were characterized and the tribological properties were investigated from room temperature to 900 °C. The results showed that NiAl/Mo-based composites were consisted of nanocrystalline B2 ordered NiAl matrix, Al₂O₃, Mo₂C, metallic Ag and vanadium oxide phase. The appearance of metallic Ag and vanadium oxide phase can be attributed to the decomposition of AgVO₃ during sintering. Wear testing results confirmed that NiAl/Mo-based composites have excellent tribological properties over a wide temperature range. For example, the friction coefficient and wear rate of NiAl/Mo-based composites containing AgVO₃ were significantly lower than the composites containing only metallic Mo or AgVO₃ lubricant when the temperature is above 300 °C, which can be attributed to the synergistic lubricating action of metallic Mo and AgVO₃ lubricants. Furthermore, Raman results indicated that the composition on the worn surface of NiAl-based composites was self-adjusted after wear testing at different temperatures. For example, Ag₃VO₄ and Fe₃O₄ lubricants were responsible for the improvement of tribological properties at 500 °C, AgVO₃, Ag₃VO₄ and molybdate for 700 °C, and AgVO₃ and molybdate for 900 °C of NiAl-based composites with the addition of metallic Mo and AgVO₃.