Research of the structure and mechanical properties of microplasm porous coatings for biomedical purposes

The purpose of this work is to justify the feasibility of using the technology of microplasma sputtering from wire materials to obtain porous coatings for biomedical purposes, the modulus of elasticity of which is close to the corresponding characteristic of human cortical bone tissue. Analyzed the influence of the technological parameters of the microplasma sputtering regime on the degree of porosity of the coating. As a result, it was found that a decrease in current strength and consumption of plasma-forming gas, as well as a decrease in the speed of feeding the sprayed wire into the plasma jet lead to an increase in the porosity of the coatings. Even though these parameters are interrelated, for each individual material are limited by certain limit values, in case of non-observance of which the stable process of melting and dispersion of the sprayed wire in the plasma jet becomes impossible. Established  the  limit  parameters of the microplasma sputtering process for titanium alloy VT1-00 and zirconium alloy KTC-110, which allows obtaining a coating with maximum porosity. Conducted studies of the adhesion strength of the obtained  coatings, formed through a low-porous sublayer, with the maximum degree of porosity according to the ASTM C633-13 (2017) method which proven that the indicators of the adhesion strength of the coatings to the VT6 titanium alloy base at normal separation meet the requirements of the international quality standard ISO 13179- 1:2021. 

[1] Shi H., Zhou P., Li J. et al., “Functional gradient metallic biomaterials: techniques, current scenery, and future prospects in the biomedical field” Frontiers Bioengineering and Biotechnologies, vol. 8, 2021, Article number 616845, 
[2] Lopata L. A., “Zavisimost modulya uprugosti poroshkovyih pokryitiy ot ih poristosti pri elektrokontaktnom pripekanii” [“Dependence of the elastic modulus of powder coatings on their porosity during electrocontact sintering”], Tehnika v silskogospodarskomu virobnitstvi, galuzeve mashinobuduvannya, avtomatizatsiya [Engineering in agricultural production, industrial machine building, automation], no. 24 (p.II), pp. 91–96, 2011. [in Russian]. 
[3]  Voinarovych S. G.,  Alontseva D. L., Kyslytsia O. N. et  al., “Fabrication and characterization of  Zr microplasma sprayed coatings for medical applications”, Advances in Materials Science, no. 2 (21), pp. 93–105, 2021, 
[4]  Moltasov  A.,  Dyman  M.,  Kaliuzhnyi  S.  et  al.,  “Dependence  of  the  elasticity  modulus  of  microplasma coatings made of titanium grade VT1-00 and zirconium grade KTC-110 on their porosity”, Series on Biomechanics, no. 2 (36), pp. 142–153, 2022, 
[5] Savich V. V. “Razrabotka tehnologii izgotovleniya i konstruktsii bestsementnogo totalnogo endoproteza tazobedrennogo sustava sistemyi SLPS (Self Locking Porous System)” [“Development of manufacturing technology and design of a cementless total hip endoprosthesis system SLPS (Self  Locking Porous System)”], I Sympozium Inzyneria Ortopedyczna I Protetyczna, IOP-97, Bialystok, 23–24 czerwca, 1997, pp. 515–525. [in Russian]. 
[6] Vilyams D. F., Rouf R.,  Implantatyi v hirurgii [Implants in surgery]. Moskow, Russia: Meditsina, 1978. [in Russian]. 
[7] Eliaz N., “Corrosion of Metallic Biomaterials: A Review”, Materials, no. 3 (12), Article number 407, 2019, 
[8] Kunčická L., Kocich R., Lowe T. C., “Advances in metals and alloys for joint replacement”, Progress in Materials Science, vol. 88, pp. 232–280, 2017, 
[9] Mehboob H., Chang S.-H., “Evaluation of the development of tissue phenotypes: Bone fracture healing using functionally graded material composite bone plates”, Composite Structures, no. 1 (117), pp. 105–113, 2014, 
[10] Tumilovich M. V., Savich V. V., Shelukhina A. I., “Influence of shape and size of particles on the osseointegration of porous implants made of titanium powder”, Doklady BGUIR 2016, no. 7 (101), pp. 115–119. 
[11] Kalita V. I., Mamaev A. I., Mamaeva V. A. et al., “Structure and shear strength of implants with plasma coatings”, Inorganic Materials: Applied Research, no. 3 (7), pp. 376–387, 2016, 
[12] Liu W., Liu S., Wang L., “Surface modification of biomedical titanium alloy: Micromorphology, microstructure evolution and biomedical applications”, Coatings, vol. 9, Article number 249, 2019, 
[13] Matassi F., Botti A., Sirleo L. et al., “Porous metal for orthopedics implants”, Clinical Cases in Mineral and Bone Metabolism, no. 2 (10), pp. 111–115, 2013. 
[14] Civantos A., Dominguez C., Pino R. J. et al., “Designing bioactive porous titanium interfaces to balance mechanical properties and in vitro cells behavior towards increased osseointegration”, Surface and Coatings Technology, vol. 368, pp. 162–174, 2019, 
[15] Matuła I., Dercz G., Barczyk J., “Titanium/Zirconium functionally graded materials with porosity gradients for potential biomedical applications”, Materials Science and Technology, no. 9(36), pp. 972–977, 2020, 
[16] Shi H., Zhou P., Li J. et al., “Functional gradient metallic biomaterials: techniques, current scenery, and future prospects in the biomedical field”, Frontiers Bioengineering and Biotechnologies, vol. 8, Article number 616845, 2021, 
[17] Oh I.-H., Nomura N., Masahashi N., Hanada S., “Mechanical properties of porous titanium compacts prepared by powder sintering”, Scripta Materialia, no. 12(49), pp. 1197–1202, 2003. 
[18] Nomura N., Oh I.-H., Hanada S. et al., “Effect of nitrogen on mechanical properties of porous titanium compacts prepared by powder sintering”, Materials Science Forum, vols. 475–479, pp. 2313–2316, 2005. 
[19]  Long  M.,  Rack  H.  J.,  “Titanium alloys in total  joint replacement  –  A  materials science perspective”, Biomaterials, no.18(19), pp. 1621–1639, 1998, 
[20] Borisov Yu. S., Kyslytsia O. M., Voinarovych S. G. et al., “Investigation of plasmatron electric and energy characteristics in microplasma spraying with wire materials”, The Paton Welding  Journal, no. 9, pp. 18–22, 
[21] Borisov Yu. S., Kyslytsia A. N., Voinarovych S. G., “Peculiarities of the process of microplasma wire spraying”, The Paton Welding Journal, no. 4, pp. 21–25, 2006.  
[22] Wejrzanowski T., Spychalski W., Różniatowski K., Kurzydłowski K., “Image based analysis of complex microstructures of engineering materials”, International Journal of Applied Mathematics and Computer Science, no. 1 (18), pp. 33–39, 2008. 
[23] Borisov Yu. S., Harlamov Yu. A., Sidorenko S. L., Ardatovskaya E. N., Gazotermicheskie pokryitiya iz poroshkovyih materialov [Gas-thermal coatings from powder materials]. Kiev, Ukraine: Naukova dumka, 1987. [in Russian].