A Comparative Analysis of Physical and Mechanical Properties of Gas-Thermal Radiation-Resistant Electrical Insulating Coatings Depending on the Application Method

The increasing demands to reliability of heavily loaded friction units such as blanket module supports (enhanced heat flux panels of the first wall, blanket module connectors) of the ITER experimental fusion reactor under construction, determine search parameters of an optimal method of thermal spraying of radiation-resistant electrical insulating coatings (EIC) Al₂O₃ and MgAl₂O₄. Extreme operating conditions of the blanket module parts with EIC (hard neutron and γ-radiation, high vacuum and high temperature, static and impact loads, frictional forces during shear) dictate strict requirements to physical and mechanical properties, chemical purity and crystal structure of oxide ceramics that provides minimal degradation of properties under the conditions of radiation exposure. In industrial production there are three competing methods of EIC deposition with the thickness of 0.1–0.5 mm, that are plasma spraying, detonation gun spraying and high velocity oxygen fuel spraying. The accumulated experience of practical application of various methods of thermal EIC spraying in combination with the results of laboratory, bench and reactor tests will make it possible to determine the optimal method of spraying for the ITER blanket modules.

References

[1] Material Assessment report 3.6 Electrical-Insulation Ceramic Coating. ITER_D_22eYPW v. 2.0., 2004.

[2] Specification for the supply of the Blanket System Components with Electrical Insulation Coatings. ITER_D_25QF6 v. 1.5.

[3] Technical Specification Insulation Coatings for the Blanket System Components. ITER_D_UKP7G3 v.1.1., 2017.

[4] Dragunov Iu.G., Leshukov A.Iu., Strebkov Iu.S., Kirillov S.Iu., Makarov S.V., Trofimovich P.D., Elkin V.N., Sviridenko M.N., Razmerov A.V., Parshutin E.V., Khomiakov S.E., Kolganov V.Iu., Safronov V.M., Putrik A.B. Razrabotka konstruktsii, izgotovlenie i eksperimental’noe obosnovanie rabotosposobnosti komponentov sistemy blanketa ITER [Development of design, manufacture and experimental proof of operational availability of ITER blanket components]. Voprosy atomnoi nauki i tekhniki. Ser. Termoiadernyi sintez [Problems of Atomic Science and Technology. Ser. Thermonuclear Fusion]. 2016, vol. 39, is. 4, pp. 13–26.

[5] ITER Vacuum Handbook. ITER_D_2EZ9UM v. 2.3.

[6] Toma F.-L., Scheitz S., Berger L.-M., Sauchuk V., Kuznezoff M., Thiele S. Comparative study of the electrical properties and characteristics of thermally sprayed alumina and spinel coatings. Journal of Thermal Spray Technology, 2011, vol. 20(1–2), pp. 195–204.

[7] Matikainen V., Niemi K., Koivuluoto H., Vuoristo P. Abrasion, Erosion and Cavitation Erosion Wear Properties of Thermally Sprayed Alumina Based Coatings. Coatings, 2014, vol. 4(1), pp. 18–36.

[8] Bolelli G., Cannillo V., Lusvarghi L., Manfredini T. Wear behavior of thermally sprayed ceramic oxide coatings. Wear, 2006, vol. 261, pp. 1298–1315.

[9] Niemi K., Hakalahti J., Hyvärinen L., Laurila J., Vuoristo P., Berger L.-M., Toma F.-L., Shakhverdova I. Influence of Chromia Alloying on the Characteristics of APS and HVOF Sprayed Alumina Coatings. Conference: ITSC 2011, International Thermal Spray Conference & Exhibition, 27–29 September 2011, Hamburg, Germany, 2011, vol. 276, pp. 1–6.

[10] Tosaki T., Kobayashi Y., Ohta K., Kitamura J. Comparable Study of Electrical and Mechanical Properties in Plasma Sprayed Alumina Coatings. Conference: ITSC 2013, International Thermal Spray Conference & Exhibition, 13–15 May, 2013, Busan, South Korea, 2013, pp. 312–317.

[11] Ouyang J.H., Sasaki S. Tribological characteristics of low-pressure plasma-sprayed Al2O3 coating from room temperature to 800°C. Tribology International, 2005, vol. 38, pp. 49–57.

[12] Deng C.-M., Zhou K.-S., Liu M., Deng C.-G., Song J.-B., Zheng Z.-G. Characteristics of Low Pressure Plasma Sprayed Alumina Coating. Journal of Inorganic Materials, 2009, vol. 24(1), pp. 117–121.

[13] Sulzer-Metco. Available at: http://www.sulzer.com/en/Products-and-Services/Turbomachinery-Services/Repair-Services/Coatings/Low-Pressure-Plasma-Spray-LPPS (accessed 21 December 2017).

[14] Gazotermicheskoe napylenie [Thermal spraying]. Ed. Baldaev L.Kh. Moscow, OOO «Staraia Basmannaia» publ., 2015. 540 p.

[15] Mchedlov S.G. Gazotermicheskoe napylenie v tekhnologii uprochneniia i vosstanovleniia detalei mashin (obzor). Ch. 1. Gazoplamennoe i detonatsionnoe napylenie (obzor) [Gas-thermal coating in machine components strengthening and reconditioning processes: A Review. Part 1. Flame and explosion spraying]. Svarochnoe proizvodstvo [Welding production]. 2007, no. 10, pp. 35–45.

[16] Shtertser A.A., Zlobin S.B., Ul’ianitskii V.Iu. Termotsiklicheskie svoistva gradientnykh pokrytii keramika-metall, poluchennykh detonatsionnym napyleniem [Thermocyclic properties of gradient ceramics-metal coatings made by detonation spraying]. Uprochniaiushchie tekhnologii i pokrytiia [Strengthening Technologies and Coatings]. 2012, no. 7, pp. 23–26.

[17] Tesa T., Musalek R., Medricky J., Kotlan J., Lukac F., Pala Z., Ctibor P., Chraska T., Houdkova S., Rimal V., Curry N. Development of suspension plasma sprayed alumina coatings with high enthalpy plasma torch. Surface and Coating Technology, 2017, vol. 325, pp. 277–288.

[18] Killinger F., Kuhn M., Gadow R. High-velocity suspension flame spraying (HVSFS), a new approach for spraying nanoparticles with hypersonic speed. Surface and Coating Technology, 2006, vol. 201, is. 5, pp. 1922–1929.

[19] Müller J.-H., Kreye H. Microstructure and properties of thermally sprayed alumina coatings. Welding and Cutting, 2001, vol. 53(6), pp. 320–326.

[20] Shakhova I., Mironov E., Azarmi F., Safonov A. Thermo-electrical properties of the alumina coatings deposited by different thermal spraying technologies. Ceramics International, 2017, vol. 43, is. 17, pp. 15392–15401.

[21] Morks M.F., Cole I., Corrigan P., Kobayashi A. Electrochemical characterization of plasma sprayed alumina coatings. Journal of Surface Engineered Materials and Advanced Technology, 2011, vol. 1, no. 3, pp. 107–111.

[22] Pogrebniak A.D., Tiurin Iu.N. Modifikatsiia svoistv materialov i osazhdenie pokrytii s pomoshch’iu plazmennykh strui [Modification of material properties and coating deposition using plasma jets]. Uspekhi fizicheskikh nauk [Advances in Physical Sciences]. 2005, vol. 175, no. 5, pp. 515–544.

[23] Kudinov V.V., Ivanov V.M. Naneseniie plazmoi tugoplavkikh pokrytii [Application of plasma refractory coatings]. Moscow, Mashinostroenie publ., 1981. 188 p.

[24] Zaitsev A.N., Leshukov A.Iu., Dubinin G.V., Sviridenko M.N., Aleksandrova Iu.P., Sachek B.Ia., Mezrin A.M. Raschet tolshchin elektroizoliatsionnykh plazmo-napylennykh oksidnykh pokrytii Al2O3 v izdeliiakh blanketa ITER [Calculation thickness of insulation plasma-sprayed oxide coating Al2O3 in the parts of ITER blanket]. Izvestiia Rossiiskoi Akademii Nauk. Energetika [Proceedings of the Russian Academy of Sciences. Power Engineering]. 2016, no. 1, pp. 79–91.

[25] Ul’ianitskii V.Iu., Batraev I.S., Shtertser A.A. Detonatsionnye pokrytiia iz oksidov [Oxide coatings made by detonation spraying]. Uprochniaiushchie tekhnologii i pokrytiia [Strengthening Technologies and Coatings]. 2015, no. 9(129), pp. 37–44.