Structure, phase composition and hardness of TiZrAlN films with different Al content

Abstract

Quaternary TiZrAlN films were grown at Ts=600°C by reactive magnetron sputtering in Ar+N2 plasma discharge from elemental targets. Deposition occurred at the constant power of Ti and Zr targets, while changing the Al power and adjusting the N2 flow rate, resulting in stoichiometric nitride films (N concentration ~ 50 at.%) with Al content up to 37 at.% and fixed Zr:Ti ratio of 1:1. It is shown that single-phase, cubic (Ti,Zr)1-xAlxN solid solutions are stabilized upon incorporation of Al. The lattice parameter of Al-containing films linearly decreases with the increase in Al concentration. For these films the maximum hardness (25 GPa) is achieved at Al content of 19 at.%