Temperature-adaptive Ni3Al-based self-lubricating alloys

Abstract

Temperature-adaptive Ni3Al-based self-lubricating alloys prepared by powder metallurgy were investigated and evaluated over a wide temperature range. Ni3Al-Ag-V alloys exhibit excellent self-lubricating properties and wear resistance over a wide temperature range, especially for the Ni3Al-20 wt%Ag-5 wt%V alloy with friction coefficients as low as 0.26 and 0.23 at room temperature and 900°C, respectively, and wear rates as low as 5 × 10− 6 mm3/Nm and 4 × 10− 5 mm3/Nm in turn. It is proposed for a lubrication mechanism that temperature-adapted lubrication is provided by the soft metal Ag at low temperatures and AgVO3 and Ag3VO4 produced by tribo-chemical reactions at high temperatures.