Corrosion resistance MAO coatings on titanium alloy

One of the promising materials used in various fields of technology, is titanium and its alloys. This is due to its favorable combination of physical and chemical properties and improved corrosion resistance to the atmospheric conditions. However, in certain corrosive media, especially in the presence of abrasion, titanium and its alloys is the subject to corrosive degradation. The electroplating method used currently to improve the corrosion resistance of metals, has several disadvantages: low ecological safety of the process associated with aggressive electrolytes used, the need for additional operations washing, degreasing, etching, strict observance of the temperature regime during processing. The resulting coatings electroplated not meet the requirements for corrosion resistance in corrosive environments, especially in the presence of abrasive wear. The paper proposes a method for improving the corrosion resistance of titanium and its alloys in corrosive environments, especially in the presence of abrasion, the metal coating on the surface of the protective layer microarc oxidation. The studies of morphology, chemical composition and thickness of the coatings were conducted. These studies have shown that in the MAO coating not only the phase y-TiO 2 is formed, but also the phase a-TiO 2, which is a major contributor to the hardened layer. Hardening of microarc oxidation during metals due to the formation on the surface coating which consists of titanium oxide and oxides of chemical elements contained in the electrolyte composition. Accelerated Laboratory Test corrosion resistance coatings showed that the coatings have MAO higher corrosion resistance as compared to coatings deposited by galvanic anodizing. Samples treated in silicate-alkaline electrolyte have the highest corrosion resistance. Process conditions for applying a corrosion resistant coating on titanium and its alloys are defined.