Tribological behavior of Ni3Al-Ag based self-lubricating alloy with Ag2MoO4 formed by high temperature tribo-chemical reaction

摘要

Tribological behavior of nickel aluminum alloy containing silver constructed by powder metallurgy was investigated in a broad temperature range. It is noticed that Ni 3 A1 alloy-20 wt% Ag exhibits favorable lubricating properties especially at and above 800 degrees C. The self-lubricating alloy possesses coefficient of friction (CoF) and wear rate (WR) low to 0.2 and 1-2 x 10(-5) mm(3)/Nm, respectively. Moreover, a lubricating mechanism is proposed that at low temperatures, Ag provides effective lubrication; while at elevated temperatures; silver molybdate created by tribological chemical reactions contributes to low CoF. It is demonstrated that combination of Ag and Ag2MoO4 is a feasible way that plays a synergistic effect and generates excellent lubricity in a wide range of temperatures.