Thermal Stability and Electrochemical Properties of Ti–Al–Mo–Ni–N Coatings Fabricated by Arc-PVD

• Published in: Protection of metals and physical chemistry of surfaces Vol. 56; no. 2; pp. 358 - 362
• Main Authors: Demirov, A. P., Sergevnin, V. S., Blinkov, I. V., Belov, D. S., Volkhonskii, A. O.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.03.2020; Springer Nature B.V
• Subjects: Aluminum; Arc deposition; Cathodic coating (process); Characterization and Evaluation of Materials; Chemistry and Materials Science; Coatings; Corrosion and Coatings; Corrosion resistance; Crystallites; Diffusion; Electrochemical analysis; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Intermetallic compounds; Materials; Materials Science; Metallic Materials; Microstrain; Molybdenum; Multilayers; New Substances; Nickel; Nitrides; Physical vapor deposition; Thermal stability; Titanium aluminides; Tribology; Arc-PVD coating; nanostructure; thermal stability; electrochemical properties
• ISSN: 2070-2051; 2070-206X
• DOI: 10.1134/S2070205120020057

— The electrochemical properties of Ti–Al–Mo–Ni–N coatings with a molybdenum content of 20 and 25 at % fabricated by cathodic arc deposition (Arc-PVD) are studied. Series 2 coatings are characterized by the presence of Mo in both a chemically bound (Mo 2 N, as with series 1 coatings) and free states (i.e., metallic phase). Considering the multilayer architecture of coatings based on the mixed nitride (TiAl)N and molybdenum-containing phases, their corrosion destruction proceeds layer by layer due to different corrosion resistance of these phases in acidic and alkaline environments. Annealing the coatings at 600°C in vacuum gives rise to diffusional processes in them that lead to a growth of crystallites of the (TiAl)N nitride phase and a decrease in the microstrain. This phenomenon is considerably more conspicuous in series 2 coatings, which can be explained by the higher diffusivity of Mo atoms in the metallic phase than in the case of their counterparts in the nitride phase.