Ni₃Al matrix high temperature self-lubricating composites

A Ni₃Al matrix high temperature self-lubricating composite Ni₃AlBaF₂CaF₂AgCr was fabricated by the powder metallurgy technique, and tribological behavior at a wide temperature range from room temperature to 800 °C was investigated. The results indicated that the composite exhibited low friction coefficients (0.300.36) and wear rates (0.652.45×10^-4 mm³ N^-1 m^-1). It was found that the low friction coefficient was attributed to the synergistic effects of Ag, fluorides and chromates formed in the tribo-chemical reaction at high temperatures. The low wear rate of the composite was due to the high strength and the excellent lubricating properties.