TiN/Cr/Al2O3 and TiN/Al2O3 hybrid coatings structure features and properties resulting from combined treatment

• Published in: Surface & coatings technology Vol. 201; no. 6; pp. 2621 - 2632
• Main Authors: Pogrebnjak, A.D., Kravchenko, Yu.A., Kislitsyn, S.B., Ruzimov, Sh.M., Noli, F., Misaelides, P., Hatzidimitriou, A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 04-12-2006; Elsevier
• Subjects: Adhesion; Applied sciences; Contact of materials. Friction. Wear; Corrosion; Corrosion environments; Corrosion prevention; Electron beam treatment; Exact sciences and technology; Hybrid process; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Nano- and micro-hardness; Nonmetallic coatings; Plasma jet; Production techniques; Protective coatings; Surface treatment; Vacuum-arc deposition; Wear and corrosion resistance; Electron beam treatment; Vacuum-arc deposition; Plasma jet; Nano- and micro-hardness; Protective coatings; Adhesion; Hybrid process; Wear and corrosion resistance; Plasma; Mechanical properties; Electron beam; Titanium nitride; Hardness; Corrosion protection; Non metal coating; Surface treatment; Corrosion resistance; Corrosion; Protective layer; Wear; Wear resistance; Alumina; Vacuum deposition; Tribology
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2006.05.018

New experimental results are presented on the structure and the elemental and phase composition of hybrid coatings, which were deposited on a substrate of AISI 321 stainless steel using a combination of plasma-detonation, vacuum-arc and subsequent High-Current Electron Beam (HCEB) treatment. We found that an increase in energy density intensified mass transfer processes and resulted in changes in aluminum oxide phase composition (γ→α and β→α). Also we observed the formation of a nanocrystalline structure in Al2O3 coatings. Electron beam treatment of a hybrid coating surface induced higher adhesion, decreased the intensity of surface wear and increased corrosion resistance in a sulphuric acid solution. The corrosion resistance of the coatings was studied in several electrolytic solutions (0.5 M H2SO4, 1 M HCl, 0.75 M NaCl) using electrochemical techniques. In most cases the corrosion resistance was improved, except those in NaCl solutions. The nano-hardness of the protecting coating was 13 GPa before electron beam melting and 9 GPa after it (as a result of TiN and Al2O3 sub-layers mixing).