National Research Tomsk State University, Tomsk, Russia

N. I. Kakhidze, Junior Researcher, Laboratory of Nanotechnologies in Metallurgy, e-mail: kakhidze.n@yandex.ru
V. D. Miroshkina, Student of the Faculty of Physics and Engineering, e-mail: Mir.vika28.11@gmail.com
A. P. Khrustalev, Senior Researcher, Laboratory of Nanotechnologies in Metallurgy, Candidate of Physical and Mathematical Sciences, e-mail: tofik0014@gmail.com
A. B. Vorozhtsov, Acting Head of Vice-Rector for Research and Innovation, Doctor of Physical and Mathematical Sciences, Professor, e-mail: abv@mail.tomsknet.ru

Current production requires light and high-strength materials to increase reliability and decrease weight and fuel consumption of means of transportation. The search is being conducted to harden aluminum alloys, showing multiple less density as compared to steel and iron. There are known approaches of dispersion strengthening of aluminum alloys with refractory particles, ensuring an increase in both strength and ductility. It is promising to use erbium fluoride, ensuring an increased density of dislocations in the alloy, and optimizing a process of producing high-strength aluminum alloys. The authors conducted research on the influence of ErF₃ sub-microparticles on the microstructure and mechanical properties of АК9 alloy. The authors studied Al – ErF₃ alloy combination as required for introducing particles in the molten metal, and combinations of composition – structure – properties of produced alloys in cast and heat-treated conditions. A modifying effect of ErF₃ particles on the structure of silumins was determined as taken place according to a crystallization front holding mechanism and grain structure refinement, a decreased formation of clusters of ferrous phases and eutectic plate-like silicon. It has been established that 1% wt. of ErF₃ added into АК9 alloy at the casting stage entailed higher homogeneity of the microstructure and refinement of an average grain size of α-Al by 21%. The effect of ErF₃ on a deformation behavior of АК9 alloy varies depending on the structural state of the alloy. Adding 1% of ErF₃ into АК9 alloy contributes to increase yield strength by 14 and 36%, tensile strength – by 16 and 34% and maximum strains – by 40 and 72% at the stages of casting and heat treatment, respectively. An increase in strength properties of the alloy is stated to be combined with a negative influence of agglomerates of particles and their clusters. The presented research results demonstrate prospects of adding ErF₃ particles into aluminum alloys. The paper describes proposed measures aimed at improving a process of manufacturing alloys for improved strengthening effect of particles.
Research was funded by the Ministry of Education and Science of the Russian Federation as part of state order No. FSWM-2020-0028.
Studies by scanning electron and optical microscopy methods and measurements of hardness and tensile strength properties of the produced alloys were carried out using equipment of the Tomsk Regional Common Use Center of National Research Tomsk State University supported by grant of the Ministry of Education and Science of the Russian Federation No. 075-15-2021-693 (No. 13.TsKP.21.0012).

1. Zakharov V. V. Effect of scandium on the structure and properties of aluminum alloys. Metal Science and Heat Treatment. 2003. Vol. 45. pp. 246–253. DOI: 10.1023/A:1027368032062
2. Hansen N. Hall–Petch relation a nd boundary strengthening. Scripta Materialia. 2004. Vol. 51. pp. 801–806. DOI: 10.1016/j.scriptamat.2004.06.002
3. Zhang Z., Chen D. L. Contribution of Orowan strengthening effect in particulate-reinforced metal matrix nanocomposites. Materials Science and Engineering: A. 2008. Vol. 483. pp. 148–152. DOI: 10.1016/j.msea.2006.10.184
4. Buranova Y. et al. Al3(Sc, Zr)-bas ed precipitates in Al – Mg alloy: Effect of severe deformation. Acta Materialia. 2017. Vol. 124. pp. 210–224. DOI: 10.1016/j.actamat.2016.10.064
5. Sitdikov O. et al. Effect of temperature of isothermal multidirectional forging on microstructure development in the Al – Mg alloy with nano-size aluminides of Sc and Zr. Journal of Alloys and Compounds. 2018. Vol. 746. pp. 520–531. DOI: 10.1016/j.jallcom.2018.02.277
6. Malopheyev S. et al. Friction-stir welding of an Al – Mg – Sc – Zr alloy in as-fabricated and work-hardened conditions. Materials Science and Engineering: A. 2014. Vol. 600. pp. 159–170. DOI: 10.1016/j.msea.2014.02.018
7. Xu C. et al. The synergic effects of Sc and Zr on the microstructure and mechanical properties of Al – Si – Mg alloy. Materials & Design. 2015. Vol. 88. pp. 485–492. DOI: 10.1016/j.matdes.2015.09.045
8. Zhang W. et al. Effects of Sc content on the m icrostructure of as-cast Al –7 wt. % Si alloys. Materials Characterization. 2012. Vol. 66. pp. 104–110. DOI: 10.1016/j.matchar.2011.11.005
9. Kim M., Hong Y., Cho H. The effects of Sc on the microstructure and mechanical properties of hypo-eutectic Al – Si alloys. Metals and Materials International. 2004. Vol. 10. pp. 513–520. DOI: 10.1007/BF03027412
10. Muhammad A. et al. High strength aluminum cast a lloy: A Sc modification of a standard Al – Si – Mg cast alloy. Materials Science and Engineering: A. 2014. Vol. 604. pp. 122–126. DOI: 10.1016/j.msea.2014.03.005
11. Pramod S. L. et al. Effect of Sc addition and T6 aging treatment on the microstructure modification and mechanical properties of A356 alloy. Materials Science and Engineering: A. 2016. Vol. 674. pp. 438–450. DOI: 10.1016/j.msea.2016.08.022
12. Xu C. et al. Optimizing strength and ductility of Al – 7 Si – 0.4 Mg foundry alloy: role of Cu and Sc addition. Journal of Alloys and Compounds. 2019. Vol. 810. 151944. DOI: 10.1016/j.jallcom.2019.151944

13. Qian H. et al. Effects of Zr additive on microstructure, mechanical properties, and fractography of Al – Si alloy. Metals. 2018. Vol. 8, No. 2. 124. DOI: 10.3390/met8020124
14. Czerwinski F. Cerium in aluminum alloys. Journal of Materials Science. 2020. Vol. 55, No. 1. pp. 24–72. DOI: 10.1007/s10853-019-03892-z
15. Ahmad R., Asmael M. B. A. Influence of lanthanum on so lidification, microstructure, and mechanical properties of eutectic Al – Si piston alloy. Journal of Materials Engineering and Performance. 2016. Vol. 25. pp. 2799–2813. DOI: 10.1007/s11665-016-2139-8
16. Mao G. et al. The effects of Y on primary α-Al and prec ipitation of hypoeutectic Al – Si alloy. Materials Letters. 2020. Vol. 271. 127795. DOI: 10.1016/j.matlet.2020.127795
17. Jia K. et al. Al – 9.00 % Si – 0.25% Mg alloys modified by ytterbium. Rare Metals. 2017. Vol. 36. pp. 95–100. DOI: 10.1007/s12598-014-0378-0
18. Voron M. M., Von Pruss M. A., Biba O. E. Micro-alloying and modification of cast aluminum alloys to increase their performance properties at higher temperatures. Review. Metal and Casting of Ukraine. 2021. No. 3. pp. 61–68.
19. Kosov Ya. I., Bazhin V. Yu. Synthesis of the aluminum-erbium alloy combination from chloride-fluoride melts. Rasplavy. 2018. No. 1. pp. 14–28. DOI: 10.7868/S0235010618010024
20. Mao G. et al. The varied mechanisms of yttrium (Y) modifying a hypoeutectic Al – Si alloy under conditions of different cooling rates. Journal of Alloys and Compounds. 2019. Vol. 806. pp. 909–916. DOI: 10.1016/j.jallcom.2019.07.107
21. Pozdniakov A. V. et al. Effect of impurities of Fe and Si on th e structure and strengthening upon annealing of the Al – 0.2% Zr – 0.1% Sc alloys with and without Y additive. Physics of Metals and Metallography. 2017. Vol. 118. pp. 479–484. DOI: 10.1134/S0031918X17050118
22. Tunçay T. et al. The effects of Cr and Zr additives on the microstructure and mechanical properties of A356 alloy. Transactions of the Indian Institute of Metals. 2020. Vol. 73. pp. 1273–1285. DOI: 10.1007/s12666-020-01970-4
23. Pandee P., Sankanit P., Uthaisangsuk V. Structure-mechanical property relationships of in-situ A356/Al3Zr composites. Materials Science and Engineering: A. 2023. Vol. 866. 144673. DOI: 10.1016/j.msea.2023.144673
24. Lin S., Nie Z., Huang H., Li B. Annealing behavior of a modified 5083 aluminum alloy. Materials & Design. 2010. Vol. 31. pp. 1607–1612. DOI: 10.1016/j.matdes.2009.09.004
25. Hu X. et al. Effects of rare earth Er additions on microstructure development and mechanical properties of die-cast ADC12 aluminum alloy. Journal of Alloys and Compounds. 2012. Vol. 538. pp. 21–27. DOI: 10.1016/j.jallcom.2012.05.089
26. Gariboldi E., Colombo M. Characterization of innovative Al – Si – Mg-b ased alloys for high temperature applications. Key Engineering Materials. 2016. Vol. 710. pp. 53–58. DOI: 10.4028/www.scientific.net/KEM.710.53
27. Shi Z. M. et al. Effects of erbium modification on the microstructure and mechanical properties of A356 aluminum alloys. Materials Science and Engineering: A. 2015. Vol. 626. pp. 102–107. DOI: 10.1016/j.msea.2014.12.062
28. Colombo M., Gariboldi E., Morri A. Er addition to Al – Si – Mg-based casting alloy: Effects on microstructure, room and high temperature mechanical properties. Journal of Alloys and Compounds. 2017. Vol. 708. pp. 1234–1244. DOI: 10.1016/j.jallcom.2017.03.076
29. Mathur V., Patel G. C. M., Shettigar A. K. Reinforcement of titanium dioxide nanopa rticles in aluminum alloy AA5052 through friction stir process. Advances in Materials and Processing Technologies. 2019. Vol. 5, No. 2. pp. 329–337. DOI: 10.1080/2374068X.2019.1585072
30. Lekatou A. et al. Aluminium reinforced by WC and TiC nanoparticles (ex-situ) and aluminide particles (in-situ): Microstructure, wear and corrosion behaviour. Materials & Design. 2015. Vol. 65. pp. 1121–1135. DOI: 10.1016/j.matdes.2014.08.040
31. Mousavian R. T. et al. Fabrication of aluminum matrix composites reinforced with na no-to micrometer-sized SiC particles. Materials & Design. 2016. Vol. 89. pp. 58–70. DOI: 10.1016/j.matdes.2015.09.130
32. Vorozhtsov S. et al. The influence of ScF3 nanoparticles on the physical and mechani cal properties of new metal matrix composites based on A356 aluminum alloy. JOM. 2016. Vol. 68. pp. 3101–3106. DOI: 10.1007/s11837-016-2141-5
33. Ko J. M. et al. Nonisomorphic ErF3 layers on Si (111) substrates grown by molecular b eam epitaxy. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 2000. Vol. 18. pp. 922–926. DOI: 10.1116/1.582276
34. Khrustalyov A. P. et al. Effect of Al3Er particles on the structure, mechanical proper ties, and fracture of AA5056 alloy after casting and deformation treatment. JOM. 2021. Vol. 73. pp. 3858–3865. DOI: 10.1007/s11837-021-04940-3
35. Singh Y. Rare earth element resources: Indian context. UK : Springer, 2020. 388 p. DOI: 10.1007/978-3-030-41353-8
36. Vorozhtsov A. B., Dammer V. Kh., Arkhipov V. A. et al. Device for mixing light metal me lts with micropowders of refractory particles and fibers. Patent RF, No. 2758953. Applied: 10.03.2021. Published: 03.11.2021.
37. Vorozhtsov A. B., Arkhipov V. A., Dammer V. Kh. et al. Molding method into chill mold for production of flat castings from aluminum and magnesium alloys. Patent RF, No. 2720331. Applied: 15.11.2019. Published: 28.04.2020.
38. Khrustalyov A. P. et al. Influence of titanium diboride particle size on structure and mechanical properties of an Al – Mg alloy. Metals. 2019. Vol. 9, No. 10. 1030. DOI: 10.3390/met9101030
39. Wang E. R. et al. Improved mechanical properties in cast Al-Si alloys by combined alloyin g of Fe and Cu. Materials Science and Engineering: A. 2010. Vol. 527. pp. 7878–7884. DOI: 10.1016/j.msea.2010.08.058
40. Khan M. H. et al. Effects of Fe, Mn, chemical grain refinement and cooling rate on the evo lution of Fe intermetallics in a model 6082 Al-alloy. Intermetallics. 2021. Vol. 132. 107132. DOI: 10.1016/j.intermet.2021.107132
41. Liu B. et al. Morphologies and сompositions of α-Al15Fe3Si2-type intermetallics in Al – Si – Fe – Mn – Cr alloys. International Journal of Metalcasting. 2022. Vol. 17. pp. 1156–1164. DOI: 10.1007/s40962-022-00843-4
42. Khrustalyov A. P. et al. Study of the effect of diamond nanoparticles on the structure and mechanica l properties of the medical Mg – Ca – Zn magnesium alloy. Metals. 2022. Vol. 12. 206. DOI: 10.3390/met12020206
43. Shaha S. K. et al. Effect of Cr, Ti, V, and Zr micro-additions on microstructure and mechanical properties of the Al – Si – Cu – Mg cast alloy. Metallurgical and Materials Transactions: A. 2016. Vol. 47. pp. 2396–2409. DOI: 10.1007/s11661-016-3365-2
44. Mavlyutov M. A. Influence of a microstructure on electrical conductivity and strength of aluminum alloys after severe plastic deformation: thesis. … of Candidate of Physical and Mathematical Sciences. Saint Petersburg : Saint Petersburg National Research University of Information Technology, Mechanics and Optics, 2018. 146 p.
45. Immanuel R. J., Panigrahi S. K. Influence of cryorolling on microstructure and mechanical properties of a cast hypoeutectic Al – Si alloy. Materials Science and Engineering: A. 2015. Vol. 640. pp. 424–435. DOI: 10.1016/j.msea.2015.06.019