The research on fabrication of Ti-Al intermetallic compound lubricating film

Abstract

Series of Ti-Al intermetallic compound lubricating films were fabricated on substrates of stainless steel by double-target reactive magnetron sputtering. Chemical composition of the films ranged from 43.20 at%Al to 67.89 at%Al by changing the relative position of substrates to the targets. According to Ti-Al equilibrium diagram, the influence of chemical composition of films on friction coefficient was studied by EDS, SEM and friction test in air without lubricant. These results prove that the friction coefficient of the films ranged from 0.05 to 0.3 at various chemical compositions. Ti-Al intermetallic compound film of Ti-45.59 at%Al shows the lowest friction coefficient (0.05) and in the range of 43.20 to 48.23 at%Al, friction coefficient is also lower than 0.1.But friction coefficient of films outside the range increases gradually to 0.3. It is suggested that films ranging from 43.20 to 48.23 at%Al formed α2Ti3Al+γ-TiAl phase which shows stratified structure effectively reducing friction and wear.