STUDY OF THE PROCESS OF COATING FORMATION DURING MICROARC OXIDATION OF TITANIUM

In this work, the structural-phase state of coatings formed on the surface of titanium by microarc oxidation (MAO) was studied. During the research, a number of experiments were carried out in which the process parameters and electrolyte composition were changed. Morphological and structural changes of the coatings were analyzed using various analytical methods, including electron microscopy and x-ray diffraction. Microarc oxidation of titanium was carried out in anodic potentiostatic mode for 10 minutes in various electrolytes based on phosphoric acid, sodium orthophosphate, potassium hydroxide and hydroxyapatite. After MDO, the microgeometry of the surface does not change, i.e. a thin coating 5-7 microns thick is formed on the titanium surface. The results of studying the surface of coatings using scanning electron microscopy showed that the most porous surface of all the studied coatings was found in coatings formed in an electrolyte with the addition of potassium hydroxide (KOH). The results of X-ray diffraction analysis showed that the main phase of the coatings are anatase and rutile. Electrolyte composition is one of the main factors in the MAO process. The research results allow us to deeply understand the process of coating formation during microarc oxidation of titanium.

1. Vladimirov B.V. Mikrodugovoe oksidirovanie magnievykh splavov (obzor) / B.V. Vladimirov i dr. // Ehlektronnaya obrabotka materialov. – 2014. – № 3. – S. 1-38. (In Russian).

2. Batyshev K.A. Mikrodugovoe oksidirovanie alyuminievykh splavov / K.A. Batyshev, A.I. Batyshev // Sovremennye tekhnologii v mashinostroenii i liteinom proizvodstve. – 2016. – S. 212-214. (In Russian).

3. Nechaev G.G. Mikrodugovoe oksidirovanie titanovykh splavov v shchelochnykh ehlektrolitakh / G.G. Nechaev // Kondensirovannye sredy i mezhfaznye granitsy. – 2012. – T. 14, № 4. – S. 453-455. (In Russian).

4. Esmaili S. Korrozionnoe povedenie i biosovmestimost' pokrytii s oksidom grafena, poluchennykh metodom mikrodugovogo oksidirovaniya na magnievom splave / S. Esmaili et al // Fizicheskaya mezomekhanika. – 2022. – T. 25, № 4. – S. 122-138. (In Russian).

5. Savushkina S.V. Issledovanie keramikopodobnykh pokrytii, formiruemykh na alyuminievykh kompozitakh metodom mikrodugovogo oksidirovaniya / S.V. Savushkina i dr. // XIV-ya Mezhdunarodnaya nauchno-tekhnicheskaya konferentsiya «Bystrozakalennye materialy i pokrytiYA». 29-30 noyabrya 2016 goda. – Litres, 2022. – S. 87. (In Russian).

6. Sitdikov V.M. Snizhenie toksichnosti otrabotavshikh gazov v kamere sgoraniya dvigatelya vnutrennego sgoraniya / V.M. Sitdikov i dr. // Trudy NAMI. – 2023. – № 4. – S. 83-95. (In Russian).

7. Ramazanova Z.M. Effect of microarc oxidation on the properties of aluminum alloy samples / Z.M. Ramazanova et al // Kompleksnoe Ispolzovanie Mineralnogo Syra. – 2023. – T. 325, №. 2. – S. 39- 46. (In English).

8. Xiao-ming W. Bioactive submicron-pore design of microarc oxidation coating on Ti6Al4V alloy prepared by selective laser melting method / W. Xiao-ming, Zh. Fu-qin // Surface and Coatings Technology. – 2022. – Vol. 444. – R. 128696. DOI: https://doi.org/10.1016/j.surfcoat.2022.128696. (In English).

9. Synthesis, corrosion, and wear resistance of a black microarc oxidation coating on pure titanium / Q. Guo et al // Surface and Coatings Technology. – 2020. – Vol. 386. – R. 125454. DOI: https://doi.org/10.1016/j.surfcoat.2020.125454. (In English).

10. Dudareva N.YU. Vliyanie rezhimov mikrodugovogo oksidirovaniya na svoistva formiruemoi poverkhnosti / N.YU. Dudareva // Vestnik Ufimskogo gosudarstvennogo aviatsionnogo tekhnicheskogo universiteta. – 2013. – T. 17. – №. 3(56). – S. 217-222. (In Russian).

11. Shatalov V.K. Mikrodugovoe oksidirovanie poverkhnostei izdelii vne vanny / V.K. Shatalov, A.O. Shtokal, A.A. Blatov // Mashinostroenie i komp'yuternye tekhnologii. – 2015. – № 3. – S. 1-14. (In Russian).

12. Dudareva N.YU. Vliyanie rezhimov mikrodugovogo oksidirovaniya na svoistva formiruemoi poverkhnosti / N.YU. Dudareva // Vestnik Ufimskogo gosudarstvennogo aviatsionnogo tekhnicheskogo universiteta. – 2013. – T. 17, № 3(56). – S. 217-222. (In Russian).

13. Plazmenno- ehlektroliticheskoe modifitsirovanie poverkhnosti metallov i splavov / Red. Suminov I.V. V 2kh tomakh. T. 2. – M.: Tekhnosfera, 2011. – 512 s. (In Russian).

14. Choe H.C. Electrochemical characteristics of Ti-6Al-4V after plasma electrolytic oxidation in solutions con-taining Ca, P, and Zn ions / H.C. Choe, W.A. Brantley // Surf. Coat. Technol. – 2017. – № 320. – R. 458-466. (In English).

15. Effect of graphene oxide additive on tribocorrosion behavior of MAO coatings prepared on Ti6Al4V alloy / Y. Zuo et al // Appl. Surf. Sci. – 2019. – № 480. – R. 26-34. (In English).

16. Corrosion protection of Ti6Al4V by a composite coating with a plasma electrolytic oxidation layer and sol-gel layer filled with graphene oxide / T. Li et al // Prog. Org. Coat. – 2020. – № 144. – R. 105632. (In English).

17. Nechaev G.G. Barotermicheskoe vozdeistvie mikrorazryadov na pokrytie, formiruemoe v protsesse mikrodugovogo oksidirovaniya / G.G. Nechaev, V.A. Koshuro // Fizika i khimiya obrabotki materialov. – 2015. – № 5. – S. 29-34. (In Russian).

18. Izmenenie fazovo-strukturnogo sostoyaniya i povyshenie mekhanicheskikh kharakteristik gazotermicheskikh pokrytii na titane posle provedeniya mikrodugovogo oksidirovaniya / Koshuro V.A. i dr. // Fundamental'nye problemy sovremennogo materialovedeniya. – 2016. – T. 13, №. 4. – S. 501-505. (In Russian).