The effect of Si content on microstructure and mechanical properties of Ti–Al–Ta–Si–N coatings

• Published in: Vacuum 2023-10, Vol.216, p.112422, Article 112422
• Main Authors: Shugurov, A.R., Kuzminov, E.D., Garanin, Yu.A., Panin, A.V., Dmitriev, A.I.
• Format: Article
• Language: English
• Subjects: Magnetron sputtering; Mechanical properties; Microstructure; Nanocomposite; Transition metal nitride coatings
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2023.112422

The evolution of the microstructure and mechanical properties of magnetron-sputtered Ti 1-x-y-zAlxTaySizN coatings with increasing the Si content from z = 0 to 0.3 is studied. Based on the results of the X-ray photoelectron spectroscopy and X-ray diffraction investigations, it is shown that the nanocomposite structure consisting of Ti–Al–Ta–Si–N crystallites and the Si3N4 amorphous tissue phase is formed in the coatings at z = 0.1. The evolution of the coating microstructure with increasing the Si content from the pronounced columnar morphology to the featureless nanocomposite morphology is demonstrated using scanning electron microscopy and transmission electron microscopy. The formation of the amorphous tissue phase in the coatings with z ≥ 0.12 is clearly shown by high-resolution transmission electron microscopy investigations. Variations of the mechanical properties of the coatings with the Si content are studied by nanoindentation. The Ti0.36Al0.44Ta0.10Si0.10N coating is found to have a maximum hardness of 41 GPa coupled with the highest H/E* and H3/E*2 ratios. •Si alloying transforms columnar Ti–Al–Ta–N coatings to nanocomposite.•Nanocomposite Ti–Al–Ta–Si–N coatings form at Si contents ≥5 at.%.•Formation of amorphous tissue phase revealed with HRTEM at 6 at.% of Si.•Ti0.36Al0.44Ta0.10Si0.10N coating has a maximum hardness of 41 GPa.