Multiwalled carbon nanotubes enhanced the friction layer evolution and self-lubricating property of TiAl-10 wt% Ag-1 wt% MWCNTs sample

The necessity of reducing energy consumption and usage of material in aerospace and aviation industries drives the further optimization of friction and wear properties of TiAl alloys. Herein, the effect of MWCNTs on the friction layer evolution and lubrication properties of TiAl-10 wt% Ag-1 wt% MWCNT (TAM) composites sliding against Si3N4 balls are studied on a ball-on-disk tribometer. The research results show that the friction coefficients and wear rates of TAM sample at 0-160 min are smaller than those of TiAl-10 wt% Ag (TA). During the process of sliding wear, MWCNTs in TAM were gradually exposed to wear scar and were tightly combined with silver, which was beneficial for the formation of lubrication film on the wear scar. Consequently, the formation of lubricating film was accelerated by the MWCNTs, and the evolution process of the friction layer of TAM sample was shortened. The excellent synergetic lubrication behavior of MWCNTs and silver in the lubricating film effectively reduced friction resistance and material loss, resulting in TAM with smaller friction coefficient and lower wear rate in comparison to TA.