OBRABOTKAMETALLOV Vol. 27 No. 4 2025 237 MATERIAL SCIENCE Study of tribological properties of silicon bronze in diff erent structural states Andrey Filippov а, *, Nikolay Shamarin b, Sergei Tarasov c Institute of Strength Physics and Materials Sciences SB RAS, 2/4 per. Academicheskii, Tomsk, 634055, Russian Federation a https://orcid.org/0000-0003-0487-8382, avf@ispms.ru; b https://orcid.org/0000-0002-4649-6465, shnn@ispms.ru; c https://orcid.org/0000-0003-0702-7639, tsy@ispms.ru Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2025 vol. 27 no. 4 pp. 221–238 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2025-27.4-221-238 ART I CLE I NFO Article history: Received: 13 August 2025 Revised: 03 September 2025 Accepted: 09 September 2025 Available online: 15 December 2025 Keywords: Electron beam Silicon bronze Structure Vibration Acoustic emission Mechanical properties Severe plastic deformation Sliding friction Funding This research was funded by Russian Science Foundation project No. 24-29-00259, https://rscf.ru/ project/24-29-00259/. ABSTRACT Introduction. Silicon bronzes are widely used in critical friction units due to their combination of corrosion resistance, machinability, electrical conductivity, and satisfactory mechanical properties. Electron beam additive manufacturing (EBAM) is promising for the production of complex parts, but it forms a large columnar grain structure, leading to anisotropy of properties and limiting their practical application. Methods of severe plastic deformation (SPD), such as multi-axis forging and rolling, are eff ective for refi ning the structure, eliminating anisotropy, and increasing strength. However, their eff ect on the overall properties of silicon bronzes has not been suffi ciently studied. Purpose of the work. The purpose of this study is a comparative analysis of the eff ect of the structural state of silicon bronze on its mechanical characteristics and tribological properties under dry sliding friction. Research methods. Samples in fi ve structural states were obtained by electron-beam additive manufacturing (1), hot rolling (2), multi-axis forging (3), rolling at room temperature (4), and low-temperature annealing after rolling (5). The structure of the samples was investigated by optical metallography and transmission electron microscopy. Mechanical tests were carried out by tensile testing of double-sided dog-bone samples and Vickers microhardness testing. Tribological tests for dry sliding friction against 52100 steel were carried out with a constant load and speed. During friction, the friction coeffi cient (FC), vibrations in the normal and tangential directions, and acoustic emission (AE) were recorded. A detailed analysis of the surface and subsurface layer of friction tracks was performed using confocal laser scanning microscopy, as well as scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS). Results and discussion. The microstructure of the samples after EBAM exhibits large columnar grains, while after hot rolling it shows large equiaxed grains with twins. Multi-axial forging results in the formation of subgrains (lamellae) (<100 nm) with a high dislocation density. Rolling leads to further refi nement of the original grains and the formation of elongated submicron grains. Low-temperature annealing forms more equiaxed submicron grains (100–200 nm) with a reduced dislocation density and high-angle boundaries. Samples with a coarse-grained structure have low strength and hardness. After SPD, the strength and hardness increase signifi cantly, and the relative elongation decreases compared to the original material. Low-temperature annealing provides maximum strength with partial restoration of ductility and a decrease in hardness. The smallest and most stable friction coeffi cient, as well as minimum vibration amplitudes (especially in the tangential direction), were recorded for samples after SPD. The greatest wear occurred for the sample in the as-received condition (hot rolling). SPD reduces wear by 2.1–2.2 times compared to the hotrolled and EBAM samples. Low-temperature annealing increases wear by 10% relative to the sample after rolling. The predominant wear mechanisms were determined to be: mixed (adhesive-oxidative) for bronze after EBAM; adhesive for hot rolled; and oxidative for samples after SPD. Based on metallographic studies, it was found that the depth of subsurface deformation is maximum for coarse-grained samples (145–155 μm) and decreases by 3.3–4.7 times after SPD. Conclusion. A comprehensive study has revealed a decisive infl uence of the structural state of 96% Cu-3% Si-1% Mn bronze on its key properties. The use of SPD methods (multi-axial forging and rolling) has proven to be highly eff ective in dramatically improving the mechanical and tribological properties of silicon bronze, regardless of the original production method (hot-rolled steel or electron beam additive manufacturing). For citation: Filippov A.V., Shamarin N.N., Tarasov S.Yu. Study of tribological properties of silicon bronze in diff erent structural states. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2025, vol. 27, no. 4, pp. 221–238. DOI: 10.17212/1994-6309-2025-27.4-221-238. (In Russian). ______ * Corresponding author Filippov Andrey V., Ph.D. (Engineering), Head of Laboratory Institute of Strength Physics and Materials Sciences SB RAS, 2/4 per. Academicheskii, 634055, Tomsk, Russian Federation Tel.: +7 999 178-13-40, e-mail: avf@ispms.ru References 1. Osintsev O.E., Fedorov V.N. Med’ i mednye splavy. Otechestvennye i zarubezhnye marki [Copper and copper alloys. Domestic and foreign brands]. 2nd ed., rev. and enl. Moscow, Innovatsionnoe mashinostroenie Publ., 2016. 360 p. ISBN 978-5-9907638-3-8. 2. Kroupa A., Zobac O., Zemanova A., Richter K.W. CALPHAD-type reassessment of Cu-Si and full assessment of the Al-Cu-Si systems. Journal of Phase Equilibria and Diff usion, 2024, vol. 45, pp. 1206–1243. DOI: 10.1007/ s11669-024-01160-5.
RkJQdWJsaXNoZXIy MTk0ODM1