Modification of Eutectic Silicium in Al-Si-Cu Cast Alloy
DOI:
https://doi.org/10.7494/jcme.2026.10.3.72Keywords:
Al-Si-Cu alloy, eutectic silicon, modifier, properties of castingAbstract
The bearing alloy AlSi10 with Cu was developed as a possible replacement for aluminium alloys with Sn and Pb. This alloy is intended for low-speed bearings operating under high pressure, which are mainly used in freight transport. An addition of strontium is often used to modify the morphology of eutectic silicon, which affects the properties of the casting. The report analyses its concentration in the alloy, as well as its changes depending on the time between its application to the melt and the actual casting process. Strontium contents above 0.05% lead to a fine and fibrous (globular in the plane of the cut) Al-Si eutectic. The alloy achieved optimal mechanical properties at a strontium content of 0.12%. Hard and brittle needles of SrAl2Si2 appear at a strontium content above 0.35%, with their higher content leading to a decrease in strength, plastic properties, and fluidity. On the other hand, they also increase the hardness and practically do not affect the notch toughness. This ‘pre-modification’ is important when the melt is expected to remain at the casting temperature for a longer period.
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[1] Hossain M.M.A.R., Ehsan A.A. & Ashique H. (2023). Modelling effects of copper on microstructure and properties of Al-Si-Cu Alloys. Material Transactions, 64 (1), 177–183. DOI: https://doi.org/10.2320/matertrans.MT-M2022070.
[2] Farkašová M., Tillová E. & Chalupová M. (2013). Modification of Al-Si-Cu cast alloy. FME Transactions, 41, 210–215. URL: https://www.mas.bg.ac.rs/_media/istrazivanje/fme/vol41/3/06_mfarakasova.pdf#:~:text=INTRODUCTION.%20The%20hypoeutectic%20Al%2DSi%20based%20alloys%20are,cast%20oil%20pans%20and%20valve%20lifters%20%5B1%5D.
[3] Grígerová T., Lukáč I. & Kořený R. (Eds.) (1988). Zlievárenstvo neželezných kovov. Bratislava/Praha: Alfa/SNTL [in Slovak].
[4] Rollason E.C. (1973). Metallurgy for Engineers. London: Edward Arnold Publisher.
[5] Zliatiny neželezných kovov. URL: http://kmi2.uniza.sk/wp-content/uploads/2020/01/5_Zliatiny-nezelezn%C3%BDchkovov.pdf [20.12.2025].
[6] Szarvasy P., Petrík J. & Ďubek J. (2001). Al-Si alloys for bearings. Materiali in tehnologije/ Materials and Technologies, 35 (1–2), 31–34. URL: http://mit.imt.si/izvodi/mit0112/szarvasy.pdf.
[7] Chalupová M., Tillová E. & Farkašová M. (2014). Microstructure analysis of AlSi10MgMn aluminium cast alloy. Materials Science Forum, 782, 365–368. DOI: https://doi.org/10.4028/www.scientific.net/MSF.782.365.
[8] Basavakumar K.G., Mukunda P.G. & Chakraborty M. (2008). Influence of grain refinement and modification on microstructure and mechanical properties of Al-7Si and Al-7Si-2.5Cu cast alloys. Materials Characterization, 59(3), 283–289. DOI: https://doi.org/10.1016/j.matchar.2007.01.011.
[9] Sun Yu., Pang S., Liu X., Yang Z. & Sun G. (2011). Nucleation and growth of eutectic cell in hypoeutectic Al-Si alloy. Transactions of Nonferrous Metals Society of China, 21(10), 2186–2191. DOI: https://doi.org/10.1016/S1003-6326(11)60993-X.
[10] COMALCO (1997). Modification of foundry Al-Si alloys. Technical report No. 4. Brisbane: Comalco Aluminum Limited.
[11] Kim Y. Ch. & Cho J.I. (2023). The effect of copper on feeding characteristics in Al-Si alloys. Journal of Korea Foundry Society, 43(6), 294–301. DOI: https://doi.org/10.7777/jkfs.2023.43.6.294.
[12] Prasada Rao A.K., Murty B.S. & Chakraborty M. (2005). Improvement in tensile strength and load bearing capacity during
dry wear of Al-7Si alloy by combined grain refinement and modification. Materials Science and Engineering A, 395(1–2), 323–326. DOI: https://doi.org/10.1016/j.msea.2004.12.053.
[13] Fracchia E., Gobber F.S. & Rosso M. (2021). Effect of alloying elements on the Sr modification of Al-Si cast alloys. Metals, 11(2), 342. DOI: https://doi.org/10.3390/met11020342.
[14] Brzezinski M., Wisniowski J., Łucarz M., Kaczmarska K., Pribulová A. & Futáš P. (2024). prediction of the stability of the casting process by the HPDC method on the basis of knowledge obtained by data mining techniques. Materials, 17(23), 5935. DOI: https://doi.org/10.3390/ma17235935.
[15] Malik J., Vasková I., Fecko D. & Futáš P. (2012). Homogenity of die casting and returning material. Archives of foundry engineering, 12(2), 61–64. DOI: https://doi.org/10.2478/v10266-012-0037-6.
[16] Selivorstov V., Dotsenko Y. & Borodianskiy K. (2017). Influence of low‐frequency vibration and modification on solidification and mechanical properties of Al‐Si casting alloy. Materials, 10(5), 560. DOI: https://doi.org/10.3390/ma10050560.
[17] Limmaneevichitr C., Pongananpanya S. & Kajornchaiyakul J. (2009). Metallurgical structure of A356 aluminum alloy solidified under mechanical vibration: An investigation of alternative semi‐solid casting. routes. Materials & Design, 30(9), 3925–3930. DOI: https://doi.org/10.1016/j.matdes.2009.01.036.
[18] Petrík J. (2009). Spôsobilosť skúšky zabiehavosti. Slévarenství, 57(3–4), 83–87 [in Slovak].
[19] Futáš P., Petrík J., Pribulová A. & Bartošová M. (2015). Fluidity test of Al-Si alloy using by computer simulation. Key Engineering Materials, 635, 45–50. DOI: https://doi.org/10.4028/www.scientific.net/KEM.635.45.
[20] ISO 6892-1:2016 Metallic materials. Tensile testing. Part 1: Method of test at room temperature. Geneva, Switzerland: International Organization for Standardization ISO.
[21] EN ISO 6507-1:2023 Metallic materials – Vickers hardness test Part 1: Test method. Geneva, Switzerland: International Organization for Standardization ISO.
[22] EN ISO 6506-1:2014 Metallic materials – Brinell hardness test Part 1: Test method. Geneva, Switzerland: International Organization for Standardization ISO.
[23] EN ISO 10045-1: 1990 Charpy impact test on metallic materials. Test method. Geneva, Switzerland: International Organization for Standardization ISO.
[24] EN ISO 6506-2:2025 Metallic materials – Brinell hardness test Part 2: Verification and calibration of testing machines. Geneva, Switzerland: International Organization for Standardization ISO.
[25] EN ISO 6507-2:2023 Metallic materials – Vickers hardness test Part 2: Verification and calibration of testing machines. Geneva, Switzerland: International Organization for Standardization.
[26] STN 42 0491:1978 Zliatiny typu AlSi na odliatky. Hodnotenie metalografickej štruktúry [in Czech].
[27] Skočovský P. & Konečná R. (1998). The quantitative metallography and microfractography utilization at evaluation of structure of cast materials. In: Metallography’98, Stará Lesná – Poprad (pp. 27–29). Košice: Hutnícka fakulta, Technická univerzita v Košiciach.
[28] Petrik J. & Rosenberg G. (2007). Vplyv premodifikovania na vlastnosti silumínu. Materials Engineering/ Materiálove inžinierstvo, 14(4), 27–30.
[29] Skočovský P. & Konečná R. (2000). Vplyv niektorých zmien mikroštruktúry na morfológiu lomových plôch. In: Fraktografia 2000: Proceedings of the international conference. Stará Lesná, 15–18.10.2000 (pp. 36–42). Košice: Technická univerzita v Košiciach [in Slovak].
[30] Timpel M., Wanderka N., Schlesiger R., Yamamoto T., Lazarev N., Isheim D., Schmitz G., Matsumura S. & Banhart J. (2012). The role of strontium in modifying aluminium-silicon alloys. Acta Materialia, 60(9), 3920–3928. DOI: https://doi.org/10.1016/j.actamat.2012.03.031.
[31] Zamani M. & Seifeddine S. (2016). Determination of optimum Sr level for eutectic Si modification in Al-Si cast alloys using thermal analysis and tensile properties. International Journal of Metalcasting, 10(4), 457–465. DOI: https://doi.org/10.1007/s40962-016-0032-8.
[32] Sigworth G.K. (2008). The modification of Al-Si casting alloys: Important practical and theoretical aspects. International Journal of Metalcasting, 2, 19–40. DOI: https://doi.org/10.1007/BF03355425.
[33] Dahle A.K., Nogita K., McDonald S.D., Zindel J.W. & Hogan L.M. (2001). Eutectic nucleation and growth in hypoeutectic Al-Si alloys at different strontium levels. Metallurgical and Materials Transactions A, 32(4), 949–960. DOI: https://doi.org/10.1007/s11661-001-0352-y.
[34] Zhang W., Ma S., Wei Z. & Bai P. (2019). The relationship between residual amount of Sr and morphology of eutectic Si phase in A356 alloy. Materials, 12(19), 3222. DOI: https://doi.org/10.3390/ma12193222.
[35] Emadi D., Gruzleski J.E. & Toguri J.M. (1993). The effect of Na and Sr modification on surface tension and volumetric shrinkage of A356 alloy and their influence on porosity formation. Metallurgical Transactions B, 24, 1055–1063. DOI: https://doi.org/10.1007/BF02660997.
[36] Djurdjevic M., Manasijevic S., Smiljanic S. & Ristic M. (2023). Quantification of modifiers fading during melt holding in the aluminum casting furnace. Crystals, 13(2), 191. DOI: https://doi.org/10.3390/cryst13020191.
[37] Lu L., Nogita K. & Dahle A.K. (2005). Combining Sr and Na additions in hypoeutectic Al-Si foundry alloys. Materials Science and Engineering A, 399(1–2), 244–253. DOI: https://doi.org/10.1016/j.msea.2005.03.091.
[38] Ebhota W.S. & Jen T.-C. (2017). Effects of modification techniques on mechanical properties of Al-Si cast alloys. In: Subbarayan S. (Ed.), Aluminium Alloys – Recent Trends in Processing, Characterization, Mechanical Behavior and Applications. London: IntechOpen. URL: https://www.intechopen.com/chapters/56755.
[39] McDonald S.D., Nogita K. & Dahle A.K. (2004). Eutectic nucleation in Al-Si alloys. Acta Materialia, 52(14), 4273–4280. DOI: https://doi.org/10.1016/j.actamat.2004.05.043.
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Copyright (c) 2026 Peter Blaško, Jozef Petrík, Lenka Girmanová, Marek Šolc, Patrik Fedorko
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