Investigation on Tribological Behavior of Ti2AlN/TiAl Composite at Room and Elevated Temperature

In current investigation, tribological properties of TiAl matrix composite reinforced with 15 vol%Ti2AlN and TiAl alloy prepared through in situ reactive method of powder metallurgy were evaluated against Si3N4 balls at room and elevated temperature. The wear mechanism along with the variation of temperature was also systematically analyzed. The results reveal that Ti2AlN/TiAl presents lower friction coefficients and wear rates in comparison with TiAl alloy at all test conditions. Along with the increment of temperature, the primary wear mechanisms of two materials both transform from abrasion wear to adhesion wear. Particularly, more efficient formation of tribo-oxidation films with protective feature on the worn surface of Ti2AlN/TiAl plays a dominant role in the improvement in wear resistance at elevated temperature. Additionally, the excellent tribological properties of the composite attribute to the other advantages of additive Ti2AlN phase, such as the load-carrying role, inhibition on the slipping of wear debris, as well as the refined microstructure of TiAl matrix phase.