Influence of Cr content on tribological properties of Ni 3Al matrix high temperature self-lubricating composites

Abstract

High temperature self-lubricating composites Ni 3Al–BaF 2–CaF 2–Ag–Cr were fabricated by powder metallurgy technique. In this paper the effect of Cr content on tribological properties at a wide temperature range starting from room temperature to 1000 °C was investigated. It was found that Ni 3Al matrix composite with 20 wt% Cr exhibited low friction coefficient of 0.24–0.37 and a wear rate of 0.52–2.32×10 −4 mm 3 N −1 m −1. Especially at 800 °C it showed the lowest friction coefficient of 0.24 and a favorable wear rate of 0.71×10 −4 mm 3 N −1 m −1. This implied that 20 wt% Cr was the optimal Cr content and its excellent tribological performance could be attributed to the balance between strength and lubricity.