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Casting and Foundry
Название Understanding the effect of structural defects in graphite on the properties of foundry coatings
DOI 10.17580/cisisr.2018.02.13
Автор I. E. Illarionov, T. R. Gilmanshina, A. A. Kovaleva, N. A. Bratukhina
Информация об авторе

Chuvash State University (Cheboksary, Russia):

I. E. Illarionov, Dr. Eng., Prof., Head of the Chair “Material Science and Metallurgical Processes”, e-mail: tmilp@rambler.ru


Siberian Federal University (Krasnoyarsk, Russia):

T. R. Gilmanshina, Cand. Eng., Associate Professor, e-mail: gtr1977@mail.ru
A. A. Kovaleva, Cand. Eng., Associate Professor
N. A. Bratukhina, Associate Professor


How the properties of protective coatings form is a complex mechanism that is yet to be studied. Because of the lack of such understanding, researchers predominantly rely on an empirical method to create protective coatings that would offer a necessary performance. In quality terms, the process of building a protective layer involves two stages: Stage 1 — properties formed during preparation in liquid state; Stage 2 — structure formed while the coating is drying. Properties start to form even during preparation when liquid protective coatings experience such processes as ion adsorption, electrocapillary and electrokinetic phenomena, material and energy transport through colloid systems, electrostatic interaction between colloidal particles. These processes govern the overall future performance and efficiency of protective coatings. The electrical double layer and the potentials arising in it play a major role in these processes. This research aims to understand the properties of aqueous suspensions with natural and mechanically activated graphites. The graphite was activated in an AGO-2 planetary centrifugal mill. The findings show that the sedimentation stability of suspensions and coatings is governed by the size of the electrical double layer in graphite particles. Due to mechanical activation, the electrical double layer of graphite grows from 0.3 to 0.4 mV, while the sedimentation stability after 24 h of settling rises from 66 to 76% and from 87 to 97% with the concentrations of graphite being 30 and 50 w/w per 100 w/w of water, correspondingly. Accumulation of structural defects in graphite particles contributes to the growth of the electrical double layer at the surface of graphite particles. This makes the contact area of the interacting phases — i.e. graphite and water — larger and produces active nuclei on the freshly produced surface.

Ключевые слова Graphite, mechanical activation, protective coatings, structural defects, cast iron, burnt-on
Библиографический список

1. Illarionov I. E. Application of fabrication technology for metal phosphate binders, core sands and moulding mixtures on their base. Chernye Metally. 2018. No. 4. pp. 13–19.
2. Kukuy D. M., Nikolaychik Yu. A., Filimonenko R. S. Structural and mechanical properties of foundry coatings modified with nanostructured materials: Formation patterns. Litiyo i Metallurgiya. 2013. No. 1(69). pp. 43–47.
3. Illarionov I. E., Shalunov E. P., Strelnikov I. A. et al. Production of quality surfaces in casting moulds and castings. Design and advanced technology in mechanical engineering and metallurgy : Proceedings of the 2nd regional conference. Cheboksary : Chuvashsky gosudarstvenny universitet im. I. N. Ulyanova, 2016. pp. 44–51.
4. Bychkov V. P., Osipova N. A., Kidalov N. A., Zubkova N. B. High-concentration water-clay suspensions. Liteynoe proizvodstvo. 2000. No. 4. pp. 20–21.
5. Berg P. P. Casting mould quality. Moscow : Mashinostroenie, 1971. 291 p.
6. Krushenko G. G., Terskova T. N., Mikhalev P. A. Foundry coatings made with superdispersed powders. Liteynoe proizvodstvo. 1982. No. 5. p. 33.
7. Illarionov I. E., Strelnikov I. A., Gartfelder V. A., Moiseeva O. V. Antipenetration coatings for casting moulds and cores used by foundries of machine building sites. I. Yakovlev Chuvash State Pedagogical University Bulletin. Series: Limit state mechanics. 2016. No. 4(30). pp. 55–60.
8. Illarionov I. E., Gamov E. S., Vasin Yu. P., Chernyshevich E. G. Metal phosphate binders and mixtures. Cheboksary : Izdatelstvo Chuvashskogo gosudarstvennogo universiteta, 1995. 524 p.
9. Valisovsky I. V. Burnt-ons on castings. Moscow : Mashinostroenie, 1983. 192 p.
10. Bataychuk A. V., Mudryi V. V. Enhanced performance of casting mould coatings. Litiyo i Metallurgiya. 2014. No. 4 (77). pp. 138–143.
11. Gilmanshina T. R., Babkin V. G., Leonov V. V., Stepanova T. N. Phase transformations in graphite coatings and their effect on surface cleanness of castings. Chernye Metally. 2017. No. 10. pp. 54–59.
12. Colloidal Stability in Aqueous Suspensions: Two Variables. Available at: http://www.brookhaveninstruments.com/literature/pdf/ZetaPlus/ColloidalStabilityOctober.pdf.
13. Yu Wei, Xie Huaqing, Chen Lifei. Nanofluids. Available at: http://cdn.intechopen.com/pdfs-wm/35437.pdf.
14. De Andrade, M. J. Study of electrical properties of 2- and 3-dimensional carbon nanotubes networks: thesis in co-tutelle to obtain the title of Doctor in Engineering. Porto Alegre, 2010. 209 p.
15. Zeta-potential. Electrical double layer. Available at: http://www.photocor.ru/theory/zeta-potential/.
16. Golovaneva N. V. The mechanism of nanofiltration membranes and the effect of key process parameters on their properties: PhD dissertation. Moscow, 2015. 156 p.
17. Mamina L. I. Understanding the effect of mechanical activation on the properties of protective and binding materials: dissertation in engineering sciences. Krasnoyarsk. 1980. 162 p.
18. Baranov V. N. Activation of graphites with different crystalline and chemical structures to be used for foundry refractories and paints: dissertation in engineering sciences. Krasnoyarsk. 2005. 131 p.
19. Lytkina S. I. Engineering and understanding of foundry coatings made with chemically and mechanochemically activated graphites: dissertation in engineering sciences. Krasnoyarsk. 2013. 132 p.
20. Gilmanshina T. R., Lytkina S. I., Zhereb V. P., Koroleva G. A. Cryptocrystalline graphite chemical-mechanical preparation for subsequent processing stages. Obogashchenie Rud. 2016. No. 2 (362). pp. 14–19
21. Gilmanshina T. R., Koroleva G. A., Baranov V. N., Kovaleva А. А. The Kureyskoye deposit graphite mechano-thermochemical modification technology. Obogashchenie Rud. 2017. No. 4. pp. 7–12.
22. Lytkina S. I., Khudonogov S. A., Koroleva, G. A et. al. Development of the state-of-the-art technologies for improvement of quality of cryptocrystalline graphite. Nanosistemi, Nanomateriali, Nanotehnologii. 2018. 16(1). pp. 83–101.
23. Boldyrev V. V., Avvakumov E. G. Fundamentals of mechanical activation, mechanical synthesis and mechanochemical technology. Novosibirsk : Sibirskoe otdelenie Rossiyskoy akademii nauk, 2009. 343 p.
24. Possible physical and chemical effects of mechanical activation. Available at: http://msd.com.ua/vse-o-penobetone/vozmozhnye-fiziko-ximicheskie-effekty-mexanoaktivacii/.
25. Khodakov G. S. Fine grinding of construction materials. Moscow : Stroyizdat, 1972. 240 p.
26. Avvakumov E. G. Mechanical activation of chemical processes. Novosibirsk : Nauka, 1986. 333 p.
27. Mamina L., Anikina V., Lytkina S. et. al. Influence of the activation time on the parameters of a graphite structure. Russian Journal of Non-Ferrous Metals. 2016. Vol. 57. No. 1. pp. 52–56.
28. Illarionov I. E., Kovaleva A. A., Gilmanshina T. R. et. al. Destruction mechanism of casting graphite in mechanical activation. CIS Iron and Steel Review. 2018. Vol. 15. pp. 15–17.
29. DT (DT-1202, DT-100, DT-300, DT-310, DT-330, DT-600, DT-700): Acoustic and electroacoustic spectrometers for dispersion characterization. Available at: http://www.all-pribors.ru/opisanie/54931-13-dt-dt-1202-dt-100-dt-300-dt-310-dt-330-dt-600-dt-700-58567.
30. Ubbelohde A. R., Lewis F. A. Graphite and its crystal compounds. Moscow : Nauka. 1968. 255 p.
31. Kurdyumov A. V., Malogolovets V. G., Novikov N. V. et al. Polymorphous modifications of carbon and boron nitrides. Moscow : Metallurgiya. 1994. 318 p.
32. Kirichenko V. G. The formation of topological defects on graphite surface. East European Journal of Physics. 2015. Vol. 2. No. 1. pp. 71–76.
33. Harris, Peter J. F. New Perspectives on the Structure of Graphitic Carbons. Critical Reviews in Solid State and Materials Sciences. 2005. No. 30. pp. 235–253.
34. Kovalev I. N. The structure of residual compounds produced by hydrolysis of graphite bisulphate: dissertation in engineering sciences. Chelyabinsk. 2005. 103 p.
35. Zhmurikov E. I., Bubnenkov I. A., Dremov V. V. et. al. Graphite in science and nuclear technology. Available at: https://arxiv.org/ftp/arxiv/papers/1508/1508.01814.pdf.

Полный текст статьи Understanding the effect of structural defects in graphite on the properties of foundry coatings