I. N. Ulianov Chuvash State University, Cheboksary, Russia:

I. E. Illarionov, Dr. Eng., Prof., Dept. of Materials Science and Metallurgical Processes, e-mail: tmilp@rambler.ru
A. V. Korolev, Cand. Eng., Associate Prof., Dept. of Materials Science and Metallurgical Processes
I. A. Strelnikov, Cand. Eng., Associate Prof., Head of the Dept. of Materials Science and Metallurgical Processes
L. A. Ivanova, Senior Lecturer, Dept. of Materials Science and Metallurgical Processes

It has been experimentally established that the introduction of lithium, sodium, and potassium dipinaconborates into a 10 % aqueous solution of monosubstituted aluminum phosphate leads to a sharp decrease in viscosity and limiting wetting angle. Based on the data obtained, it was concluded that the acceptable content of dipinaconborate is 8–10 wt %, at which the viscosity and limiting wetting angle characteristics meet the requirements for the practical use of binders for cold-hardening mixtures in foundry production. It was found that dipinaconborates increase the binding property of monosubstituted aluminum phosphate. At the same time, the binding property of aluminum dipineconborate phosphate compositions increases in the series of dipineconborates: potassium dipineconborate < sodium dipineconborate < lithium dipineconborate. The aluminum dipineconborate phosphate composition is a combination of monosubstituted aluminum phosphate with lithium, sodium and potassium dipineconborate separately. On the basis of aluminum dipineconborate phosphate binders, core and molding cold-hardening mixtures have been developed with the composition, %: sand 2K1O202 (GOST 2138–91) - 80; clay PZ (GOST 3226-93) - 10; aluminum dipineconborate phosphate binder in the form of a 20 % aqueous solution - 10. Aluminum dipineconborate phosphate mixtures were tested for such physical and mechanical properties as durability, friability, mouldability, strength, residual strength and knockout work. The obtained characteristics of the developed mixtures for the manufacture of molds and cores for steel and iron castings meet the requirements of foundry practice and can be recommended for the manufacture of cores and molds cured in cold tooling.

1. Dibrov I. А. Foundry - the progress of mechanical engineering. Proceedings of the XIV International Congress of Foundry Workers. Kazan: Russian foundry association, 2019. pp. 3–18.
2. Livshits V. B., Kushnir А. P. Features of the formation of a casting`s surface layer in contact with the mold coatings. Liteynoe proizvodstvo. 2022. No. 1. pp. 7–9.
3. Ermolenko А. А., Tkachenko S. S., Znamenskiy L. G. On the issues of energy saving in the production of castings using an environmentally friendly process. Liteynoe proizvodstvo. 2022. No. 1. pp. 10–12.
4. Evstifeev Е. N., Smirnov V. N., Bessarabov V. S., Kotova L. А., Zhuravlev А. V. Environmentally friendly technology for the manufacture of cold hardening phosphate mixtures. Mezhdunarodny zhurnal prikladnykh i fundamentalnykh issledovaniy. 2011. No. 6. pp. 41–43.
5. Ermolenko А. А., Tkachenko S. S., Kolodiy G. А., Znamenskiy L. G. Cold hardening mixtures based on aluminoborphosphate concentrate. State and development prospects (inorganic versus organic). Liteynoe proizvodstvo. 2021. No. 1. pp. 16–20.
6. Tkachenko S. S., Kolodiy G. А., Znamenskiy L. G., Ermolenko А. А. About highly efficient and environmentally friendly foundry technology. Chernye Metally. 2019. No. 2. pp. 25–29.
7. Leushin I. О., Koshelev О. S., Leushina L. I., Markov А. I. Production of rods for steel and iron casting from mixtures with a binder based on a combination of inorganic salts. Chernye Metally. 2022. No. 1. pp. 28–33.
8. Leushin I. О., Grachev А. N., Leushina L. I., Koshelev О. S., Markov А. I. Inorganic salts and their combinations as binders for core mixtures. Zagotovitelnoe proizvodstvo v mashinostroenii. 2021. Vol. 19, No. 4. pp. 147–152.
9. Neglinskiy О. I., Маtео-larrauri (Loramendi) J. Development and prospects for the production technology of sand cores with inorganic binders. Liteyshchik Rossii. 2019. No. 1. pp. 21–24.
10. Tikhomirova I. N., Belyakov A. V., Zakharov A. I., Makarov A. V. Degree of silicic acid polymerization in alkali-matal silicate solutions. Glass and Ceramics. 2017. Vol. 74. Iss. 5–6. pp. 220–223.
11. Kolodiy G. А., Tkachenko S. S., Krivitskiy V. S. The prospect of using phosphate cold-hardening mixtures. Liteyshchik Rossii. 2004. No. 8. pp. 23–24.
12. Polzin H., Kooyers T. Anorganisches Kernbindersystem für den Eisenguss – ein neuer Ansatz. Giesserei. 2018. No. 10. pp. 42–47.
13. Zach A., Kleinert B., Nitsch M., Nitsch U. Anorganische Kernbinderreste in bentonitischen Formstoffsystemen. Giesserei. 2020. No. 10. pp. 34–40.
14. Sudaks L. G. Phosphate binding systems: (monograph). Saint Petersburg: RIA «Kvintet», 2008. 254 p.
15. Znamenskikh L. G., Vertsyukh S. S., Varlamov А. S., Sudarikov М. V. Corundum molds on aluminum boron phosphate concentrate in precision casting. Vestnik YuUrGU. 2012. No. 39. pp. 52–55.
16. Polzin H. Anorganische Binder: Zur Form- und Kernherstellung in der Gießerei. Verlag: Schiele & Schön, 2019. 228 p.
17. Illarionov I. Е., Pestryaeva L. Sh., Sadetdinov Sh. V., Strelnikov I. А., Zhirkov Е. N. Development of heat-insulating mixtures for the of steel castings using phosphate borates. Chernye Metally. 2020. No. 7. pp. 28–33.
18. Strelnikov I. А., Pestryaeva L. Sh., Sadetdinov Sh. V. Effect of carbamide borate modifier on the strength of the molding sand and the quality of castings from magnesium alloys. Liteynoe proizvodstvo. 2021. No. 4. pp. 12–15.
19. Strelnikov I. А., Pestryaeva L. Sh., Sadetdinov Sh. V. Effect of dipinaconborates on the physical and mechanical properties of lignosulfonate binders and mixtures. Liteyshchik Rossii. 2020. No. 11. pp. 25–28.
20. Illarionov I. Е., Pestryaeva L. Sh., Sadetdinov Sh. V., Moiseeva О. V. Effect of phosphate borate compounds on the physical and mechanical properties of a furan mixture. Zagotovitelnoe proizvodstvo v mashinostroenii. 2019. Vol. 17. No. 8. pp. 339–341.
21. Sadetdinov Sh. V., Pestryaeva L. Sh., Fadeev I. V., Pestryaev D. А. Increasing the corrosion resistance of carbon steel by means of dipinaconborate compounds. Chernye Metally. 2020. No. 11. pp. 40–45.
22. Strelnikov I. А., Pestryaev D. A., Sadetdinov Sh. V. Effect of dipinaconborates on the corrosion resistance of St3 steel in solutions of synthetic detergents. Uprochnyayushchie tekhnologii i pokrytiya. 2021. Vol. 17. No. 3 (195). pp. 131–134.
23. GOST 8420–74. Paint and lacquer materials. Method for determination of relative viscosity. Introduced: 01.01.1975.
24. Bulitko Е. V. Study of the composition of a cold hardening mixture based on a phosphate binder. Tekhnologii metallurgii, mashinostroeniya i materialoobrabotki. 2018. No. 17. pp. 65–70.
25. Illarionov I. Е. Application of fabrication technology for metal phosphate binders, core sands and moulding mixtures on their base. Chernye Metally. 2018. No. 4. pp. 13–19.
26. Strelnikov I. А., Illarionov I. Е., Pestryaev D. A., Sadetdinov Sh. V. Formation of physical and mechanical properties of mixtures based on phosphate-borate binders. Liteyshchik Rossii. 2021. No.12. pp. 35–39.
27. GOST 2138–91. Moulding sands. General specifications. Introduced: 01.01.1993.
28. GOST 3226–93. Moulding refractory clays. General specifications. Introduced: 01.01.1995.
29. GOST 23409.7–78. Moulding sands, moulding and core sand mixtures. Methods for determination of compressive, tensile, bending and shearing strength. Introduced: 01.01.1980.
30. Leushin I. O., Subbotin A. Yu., Geiko M. A. Cold-hardening mixture for production of casting cores and moulds. Patent RF, No. 2705823. Applied: 18.04.2019. Published: 12.11.2019, Bulleten No.32.
31. Evstifeev Е. N., Savuskan Т. N. Low-toxic cold-hardening mixtures based on modified technical lignosulfonates. Mezhdunarodny zhurnal prikladnykh i fundamentalnykh issledovaniy. 2013. No. 10–2. pp. 270–273.
32. GOST 23409.6–78. Moulding sands, moulding and core sand mixtures. Methods for determination of gas permeability. Introduced: 01.01.1980.
33. GOST 23409.15–78. Moulding sand mixtures. Methods for determination of mouldability. Introduced: 01.01.1980.
34. Ermolenko А. А., Znamenskiy L. G., Tkachenko S. S. Advanced processes of form formation on inorganic binders. Liteynoe proizvodstvo. 2021. No. 11. pp. 9–15.
35. Dmitriev E. А., Sviridov А. V. Investigation of properties of molding sands with a binder based on inorganic salts. Uchenye zapiski Komsomolskogo-na-Amure gosudarstvennogo tekhnicheskogo universiteta. 2016. Vol. 1. No. 3 (27). pp. 72–79.
36. Medvedev Ya. I., Valisovskiy I. V. Technological tests of molding materials. Moscow: Mashinostroenie, 1973. 312 p.