저널

In this study, the influence of silicon contents on the microstructure, mechanical and tribological properties of Ti–Al–Si–N coatings were systematically investigated for application of cutting tools. The composition of the Ti–Al–Si–N coatings were controlled by different combinations of TiAl2 and Ti4Si composite target powers using an arc ion plating technique in a reactive gas mixture of high purity Ar and N2 during depositions. Ti–Al–Si–N films were nanocomposite consisting of nanosized (Ti,Al,Si)N crystallites embedded in an amorphous Si3N4/SiO2 matrix. The instrumental analyses revealed that the synthesized Ti–Al–Si–N film with Si content of 5.63 at.% was a nanocomposites consisting of nano-sized crystallites (5–7 nm in dia.) and a three dimensional thin layer of amorphous Si3N4 phase. The hardness of the Ti–Al–Si–N coatings also exhibited the maximum hardness value of about 47 GPa at a silicon content of ~5.63 at.% due to the microstructural change to a nanocomposite as well as the solid-solution hardening. The coating has a low friction coefficient of 0.55 at room temperature against an Inconel alloy ball. These excellent mechanical and tribological properties of the Ti–Al–Si–N coatings could help to improve the performance of machining and cutting tool applications.

Ti–Al–Si–N, Nanocomposite, Superhard, Tribological behavior, Arc ion plating.