Volgograd State Technical University (Volgograd, Russia)
N. A. Kidalov, Dr. Eng., Prof., Head of the Dept. of Foundry Machines and Technology
A. A. Belov, Cand. Eng., Associate Prof., Dept. of Foundry Machines and Technology, aa-belov@bk.ru
N. V. Belova, Cand. Eng., Associate Prof., Dept. of Foundry Machines and Technology
V. V. Aushev, Postgraduate Student, Dept. of Foundry Machines and Technology
S. R. Polyak, 2nd Category Engineer, Postgraduate Student, Dept. of Foundry Machines and Technology
A. I. Bogdanov, Cand. Eng., Associate Prof., Dept. of Materials Science and Composite Materials
This work is part of a study conducted under Russian Science Foundation Project No. 25-23-20098, dedicated to studying the structure formation and material properties of multilayer ceramic investment casting molds during their interaction with process additives and under the influence of ferrous and non-ferrous metal melts. It was previously established that in order to ensure favorable conditions for the removal of thermal degradation products of the residual model composition and ethoxy groups of the binder before pouring the mold with liquid metal, as well as to create conditions for volumetric softening of all layers of the ceramic shell during their heating at the crystallization of the resulting castings, it is necessary to use several ceramic suspension compositions with individual additives. Thus, the use of individual suspension compositions for the production of the facing and supporting layers of the ceramic mold resulted in a 64.71% decrease in residual strength and an increase in gas permeability from 3 to 8 units. Based on a study of the fractures of control (without additives) and experimental samples of the ceramic mold material with technological additives (magnesium sulfate and a by-product of organic origin formed during the preparation of coffee drinks in coffee machines) after physical and mechanical testing using the scanning electron microscopy method, relationships were established between the formation of the strength and gas permeability of the mold and parameters of the microstructure (volume fraction and pore size), including defects formed due to the thermal destruction of technological additives at the stages of heat treatment at temperatures characterizing the calcination of the casting mold before pouring with liquid metal and its heating during the solidification of castings from iron-carbon alloys. By identifying compounds formed as a result of the chemical interaction of ceramic mold material and process additive components using X-ray diffraction analysis, we clarified the mechanism of microstructure formation and properties of the studied ceramic materials after calcination at temperatures corresponding to the process stages of investment casting.
This study was supported by grant No. 25-23-20098 from the Russian Science Foundation, https://rscf.ru/project/25-23-20098/, and the Volgograd Region Administration (Agreement No. 3 dated July 30, 2025).
1. Evstigneev A. I. Special technologies of foundry production: in 2 parts. Part 2. Moscow : Mashinostroenie, 2012. 436 p.
2. Leushin I. O., Leushina L. I., Larin M. A., Andreev I. A. Mechanisms of sintering of precision casting molds. Liteyshchik Rossii. 2023. No. 2. pp. 8–11.
3. Repyakh S. I. Technological principles of investment casting. Dnepropetrovsk: Lira, 2006. 1056 p.
4. Venkat Y. et. al. Ceramic shell moulds with zircon filler and colloidal silica binder for investment casting of shrouded low-pressure turbine blades. Ceramics International. 2020. Vol. 46. No. 17. pp. 26572–26580.
5. Illarionov I. E., Nikitin A. V. Development of mixtures for investment casting molds using borate complexes. Liteynoe proizvodstvo. 2025. No. 7. pp. 30–34.
6. Zakharov N. A., Znamensky L. G., Sinitsyn E. A. Ceramic rods on the “Inorganika” binder for castings of the oil and gas complex. Liteynoe proizvodstvo. 2024. No. 5. pp. 18–21.
7. Kumar S., Karunakar D. B. Characterization and properties of ceramic shells in investment casting process. International Journal of Metalcasting. 2021. Vol. 15 (1). pp. 98–107.
8. Illarionov I. E., Nikitin A. V. Development of a suspension using tetraboron phosphate compounds for the manufacture of shell molds in investment casting. Liteynoe proizvodstvo. 2026. No. 1–2. pp. 33–38.
9. Wisniewski P. и др. Molding Binder Influence on the Porosity and Gas Permeability of Ceramic Casting Molds. Materials. 2020. Vol. 13. No. 12. pp. 2735.
10. Parshukova N. Yu. Use of additives to improve the properties of ceramic molds in investment casting. Izvestiya vysshikh uchebnykh zavedeniy. Chernaya metallurgiya. 2013. No. 2. pp. 69–70.
11. Chernov V. P., Safonova E. A. TPP ash as a refractory filler for suspension in investment casting. Liteyshchik Rossii. 2015.No. 6. pp. 32–35.
12. Ovchinnikova A. O., Zhuravlev Ya. A., Furman I. E. Use of aluminosilicate hollow microspheres in the creation of a ceramic shell for investment casting. Liteynoe proizvodstvo. 2024. No. 12. pp. 18–20.
13. Kidalov N. A., Belov A. A., Belova N. V. et al. Selection of technological additives to reduce the residual strength of the material of ceramic molds for investment casting. Part 1. Tekhnologiya metallov. 2026. No. 6. pp. 2–7.
14. Tamta K., Karunakar D. B. Enhancing mechanical properties and permeability of ceramic shell in investment casting process. Materials and Manufacturing Processes. 2018. Vol. 34. No. 6. pp. 612–623.
15. Kumar S., Karunakar D. B. Enhancing the Permeability and Properties of Ceramic Shell in Investment Casting Process Using ABS Powder and Needle Coke. International Journal of Metalcasting. 2019. Vol. 13. No. 3. pp. 588–596.
16. Kidalov N. A., Belov A. A., Belova N. V., Polyak S. R. Evaluation of possibility of using a complex technological additive to reduce the residual strength of sand-liquid glass mixtures used for production of steel castings. Chernye Metally. 2025. No. 2. pp. 41–46.
17. Kidalov N. A., Belov A. A., Belova N. V. et al. Selection of technological additives to reduce the residual strength of the material of ceramic molds for investment casting. Part 2. Tekhnologiya metallov. 2026. No. 7. рр. 2–8.