The Effect of Microarc Oxidation on the Structure and Hardness of Aluminum-Oxide Coatings Formed by Plasma Spraying on Titanium

• Published in: Protection of metals and physical chemistry of surfaces Vol. 54; no. 5; pp. 840 - 844
• Main Authors: Koshuro, V. A., Fomin, A. A., Rodionov, I. V., Fomina, M. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.09.2018; Springer Nature B.V
• Subjects: Aluminum oxide; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coating effects; Corrosion and Coatings; Crystal structure; Current density; Hardness; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Materials and Coatings; Materials Science; Metal oxides; Metallic Materials; New Substances; Oxidation; Oxide coatings; Plasma spraying; Porosity; Structural members; Titanium alloys; Titanium base alloys; Tribology
• ISSN: 2070-2051; 2070-206X
• DOI: 10.1134/S207020511804007X

Coatings formed by plasma spraying of electrocorundum on VT6 titanium alloy and subsequent microarc oxidation at different current densities were examined. The parameters of structure and hardness of metal-oxide layers were studied. The effect of current density on them was also found. During microarc oxidation, the open porosity (from 50.3 ± 4.5 to 10.3 ± 1.5%), the thickness (from 47.4 ± 3.3 to 30.2 ± 5.3 μm), and the average size of structural elements of presprayed coating were decreased, while its hardness was increased from 760 ± 486 to 875 ± 238 HV 2 . The magnitude of changes in the structure of the plasma coatings depended on the current density during modification. Microarc oxidation makes it possible to form structural elements in the form of pores and crystals with a size from 15 to 150 μm on the surface of sprayed aluminumoxide coatings.