Wear and oxidation behavior of reactive sputtered δ-(Ti,Mo)N films deposited at different nitrogen gas flow rates

Abstract The wear properties of δ-(Ti,Mo)N films deposited at low and high nitrogen gas flow rates ( f N 2 ) were investigated. The film at f N 2 =2.0 sccm showed better adhesive wear resistance than that at f N 2 =0.3 sccm. Such improvement in the film at f N 2 =2.0 sccm was due to the formation of Mo oxide debris by wear oxidation. It was found that Mo oxidation more easily occurred in the film at f N 2 =2.0 sccm than in the film at f N 2 =0.3 sccm. Thermodynamic consideration indicated that since the activity of Ti in δ-(Ti,Mo)N decreases with increasing N content, Mo oxidation is promoted in the film at f N 2 =2.0 sccm, which leads to better wear properties.