Microstructure and tribological behavior of TiAlSiN coatings deposited by deep oscillation magnetron sputtering

TLDR

Pulsed magnetron sputtering techniques that generate highly ionized species and high plasma density enable tailoring of coating composition, structure, and properties. TiAlSiN coatings were deposited by deep oscillation magnetron sputtering at various negative substrate biases on a TiAlSi target in Ar/N₂, and the wear mechanism evolved from severe adhesive/oxidative/abrasive to mild oxidative to severe oxidative wear. Increasing bias from –30 to –120 V decreased (111) orientation and grain size, increased residual stress and roughness, produced a nc‑TiAlN/a‑Si₃N₄ nanocomposite, and yielded maximum hardness (42.4 GPa) and modulus (495 GPa) at –120 V; at –60 V the coatings achieved the highest H/E* (0.095) and H₃/E*² (0.332) ratios, excellent adhesion (HF > 1), a low COF of 0.35, and a wear rate of 2.1 × 10⁻⁷ mm³ N⁻¹ m⁻¹, with high hardness and ratios reducing COF and wear through refined grains and oxide layer formation.

Abstract

Abstract Development of pulsed‐techniques aimed to generate highly ionized target species and high plasma density opens up a new way to tailor composition, structure, and properties of coatings. In this work, TiAlSiN coatings have been deposited at various negative substrate biases ( V s ) using deep oscillation magnetron sputtering by sputtering a TiAlSi compound target in Ar/N 2 mixtures. The increase in V s from −30 to −120 V resulted in a decrease in (111)‐preferred orientation and grain size, together with the increase in residual stress and rough morphology. The nc‐TiAlN/a‐Si 3 N 4 nanocomposite structure was obtained in coatings. The highest hardness and Young's modulus reached 42.4 and 495 GPa at −120 V, respectively. However, at −60 V, the coatings with the highest H/E* and H 3 /E* 2 ratios of 0.095 and 0.332 exhibited excellent adhesion with above HF 1 level, the lowest coefficient of friction ( COF ) of 0.35 and specific wear rate of 2.1 × 10 −7 mm 3 N −1 m −1 . Wear mechanism changed from the mixture of severe adhesive, oxidative and abrasive wear to mild oxidative wear to severe oxidative wear. TiAlSiN coatings with high hardness and H/E* and H 3 /E* 2 ratios exhibited the decrease in COF and wear rate due to refined grains in uniform distribution, which well promoted oxide layers formed on sliding contact surface.