Effect of nitrogen content on structural and mechanical properties of AlTiZrTaHf(-N) high entropy films deposited by reactive magnetron sputtering

Abstract

There is a growing interest in the design of high entropy alloys due to their remarkable properties and applications in various fields such as aerospace, medical and automotive. AlTiTaZrHf(-N) high entropy metal-sublattice nitrides were deposited in various argon‑nitrogen gas mixtures on glass and silicon substrates. X-ray diffraction analyses reveal a transition from amorphous to an FCC single phase by increasing the nitrogen content. The films have compact or columnar morphology depending on the nitrogen flow rate. Energy dispersive spectroscopy analysis shows a decreasing of the matals content as the nitrogen flow rates ratio R N2 = N 2 /Ar + N 2 increases. XPS surface analysis reveal the formation of nitrides when the nitrogen is introduced. Evolution of hardness and Young's modulus are discussed and the maximum values are obtained for a flow rates ratio R N2 of 10% at 27.67 GPa and 205.56 GPa respectively. The same film reveals good tribological properties compared to other films. This work conclusively demonstrates that high entropy metal-sublattice nitrides can be generated in an efficient way with tunable properties. • Multicomponent AlTiTaZrHf(-N) deposited by reactive magnetron sputtering • Effect of nitrogen content on microstructure, mechanical properties and tribological performance studied • H and E are monitored by controlling the stoichiometric of N/Me.