Mechanical properties of Ti-Al-N coatings obtained by the caa-pvd method followed by annealing in vacuum

Abstract

Ti-Al-N coatings were obtained on titanium substrates using the controlled accelerated vacuum deposition (CAA-PVD) method. The elemental and phase composition, morphology of the coatings before and after heating in vacuum at 900°C were studied using the methods of electron and X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray diffraction. The mechanical properties of unannealed Ti-Al-N coatings and those annealed at 900°C were assessed. It was found that heating at 900°C in vacuum leads to the formation of a homogeneous coating including the Ti2AlN, TiN1-x, and Ti 2N phases, while an increase in the coating hardness and a decrease in the friction coefficient are observed. For an unannealed Ti-Al-N coating, the Vickers hardness is 10.9 GPa, the friction coefficient is 0.40–0.47. The Ti-Al-N coating annealed at 900°C is characterized by a Vickers hardness of 15.6 GPa and a friction coefficient of 0.17.