Morphology and chemical composition of composite electrochemical coatings Zn-Al2O3 and Zn-PTFE
Abstract
The effect is studied of addition of hydrophilic aluminum oxide and hydrophobic polytetrafluoroethylene on the morphology and chemical composition of zinc coatings from acidic electrolytes. Inclusion of hydrophobic polytetrafluoroethylene particles into zinc coatings from acidic zinc electrolytes in the absence of any surfactants is more facilitated than that of hydrophilic aluminum oxide particles of various dispersion and phase composition. The formation of composite electrochemical Zn-Al2O3 and Zn-polytetrafluoroethylene coatings is determined by the state of the surface of the growing zinc deposit (its comparative hydrophobicity) that facilitates the adhesion of hydrophobic polytetrafluoroethylene particles. Addition of aluminum oxide particles into the electrolyte causes no fundamental changes in the overall surface morphology of the zinc deposits. However, a relatively large number of inclusions of aggregates of nanosized aluminum oxide particles are observed over the entire coating surface. The concentration of aluminum oxide inclusions in Zn-Al2O3 composite coatings reaches 5...7 wt.%. The surface of Zn-polytetrafluoroethylene deposit is represented by globules. The total polytetrafluoroethylene content in the obtained composite coatings reaches 30 wt.%. An increased oxygen content is found in such coatings. It is probably explained by formation of a relatively larger amount of surface zinc oxide due to the significant development of the surface morphology of the deposits.
About the Authors
I. G. BotryakovaRussian Federation
Inna G. Botryakova, Ph.D. in Chemistry, senior researcher
31/4, Leninskiy pr., Moscow
A. D. Aliev
Russian Federation
Ali D. Aliev, Ph.D. in Physics and Mathematics, leading researcher
31/4, Leninskiy pr., Moscow
N. A. Polyakov
Russian Federation
Nikolay A. Polyakov, Ph.D. in Chemistry, Head of Laboratory
31/4, Leninskiy pr., Moscow
References
1. Saifullin, R. S. (1983). Inorganic Composite Materials. Moscow: Khimiya.
2. Antropov, L. I., Lebedinskii Yu. N. (1986). Composite electrochemical coatings and materials. Kiyev: Technika.
3. Guryanov, G. V. (1985). Electrodeposition of wear resistant compositions. Kishinev: Shtiintsa.
4. Walsh, F. C., Wang, S., & Zhou, N. (2020). The Electrodeposition of Composite Coatings: Diversity, Applications and Challenges. Current Opinion in Electrochemistry. doi:10.1016/j. coelec.2020.01.011.
5. Erten, Ü., Ünal, H. ., Zor, S. et al. (2015) Structural and electrochemical characterization of Zn–TiO2 and Zn–WO3 nanocomposite coatings electrodeposited on St 37 steel. J. Appl. Electrochem (45,) 991-1003. doi: 10.1007/s10800-015-0865-5.
6. Boshkov, N., & Boshkova, N. (2017). Application of PEO75PPO30PEO75 stabilised polymeric micelles for improved corrosion resistance of composite zinc coatings. Transactions of the IMF, 95(6), 316-320. doi: 10.1080/00202967.2017.1342460.
7. Berçot, P., Peña-Muñoz, E., & Pagetti, J. (2002). Electrolytic composite Ni–PTFE coatings: an adaptation of Guglielmi’s model for the phenomena of incorporation. Surface and Coatings Technology, 157(2-3), 282-289. doi: 10.1016/s0257-8972(02)00180-9.
8. Guo, Z., Xu, R., & Zhu, X. (2004). Studies on the wear resistance and the structure of electrodeposited RE-Ni-W-P-SiC-PTFE composite materials. Surface and Coatings Technology, 187(2-3), 141-145. doi: 10.1016/j. surfcoat.2004.05.034.
9. Duran Delgado O. A., Skibina L. M. (2019). The effect of indole on kinetics of electrodeposition and morphology of cadmium and nikel coatings. Theory and Practice of Corrosion Protection, 24(3), 46-55. doi:10.31615/j.corros.prot.2019.93.3-6.
10. Vetlugin, N. A., Grafov, O. Yu., Polyakov, N. A. (2016). Effects of Caprolactam on the Process of Electrodeposition and Properties of Coatings from Sulfate-Oxalate Cr(III) Solutions. Theory and Practice of Corrosion Protection, (81), 63-71.
Review
For citations:
Botryakova I.G., Aliev A.D., Polyakov N.A. Morphology and chemical composition of composite electrochemical coatings Zn-Al2O3 and Zn-PTFE. Theory and Practice of Corrosion Protection. 2020;25(1):59-63. (In Russ.)