Abstract
Technological regimes for producing wrought products (2 and 1 mm) from the Al–4.5%Zn–2.5%Mg–2.5%Ca–0.5%Fe–0.2%Zr–0.1%Sc experimental alloy, including thermomechanical processing at temperatures of 400–450°C and a reduction ratio up to 98%, as well as softening annealing of the sheet metal at 350–400°C for 1–2 h, are presented. It is found that the as-cast structure consists of eutectic phases (Al, Zn)4Ca, Al10CaFe2, and a nonequilibrium T-phase Al2Mg3Zn3 with a size from 5 to 25 μm located along the boundaries of dendritic cells (Al). Zirconium and scandium in solid solution out of solidification are observed. After hot rolling, the structure of 2-mm sheets consists of oriented discrete intermetallic particles and their conglomerates up to 40 μm in scale in the (Al) matrix. The structure of 1-mm sheets is characterized by greater fineness and uniformity of structure. An analysis of the fine structure of deformed semifinished products using transmission electron microscopy (TEM) shows that the size of nanoparticles of the Al3(Zr,Sc) phase of the L12 structural type does not exceed 20 nm in cross section. In wrought semifinished products, the following level of mechanical properties is achieved: ultimate strength σu ~ 310–330 MPa and yield strength σ0.2 ~ 250–280 MPa with a relative elongation δ ~ 4.5–7.0%. The possibility of using argon-arc welding with standard AMg5 wire as an additive material is studied. It is shown that the new alloy does not show a tendency to form hot cracks. According to the results of X-ray tomography, the percentage of porosity in the weld is 1.27 vol %. The prevalent pore diameter does not exceed 0.2 mm. In general, the resulting structural and qualitative parameters of welded joints contribute to obtaining a strength of 75% of the strength index of the initial deformed semifinished products (sheets), which is achieved by stabilizing annealing at a temperature of 350°C for 3 h.
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REFERENCES
Drits, A.M. and Ovchinnikov, V.V., Svarka alyuminievykh splavov (Aluminium Alloys Welding), Moscow: Ruda i Metally, 2017.
Sheppard, T., Extrusion of Aluminium Alloys, Springer US, 1999. https://doi.org/10.1007/978-1-4757-3001-2
Kaigorodova, L.I., Zamyatin, V.M., and Popov, V.I., The influence of homogenizing conditions on the structure and properties of an Al-Mg alloy, Phys. Met. Metallogr., 2004, vol. 98, no. 4, pp. 407–414.
Kishchik, M.S., Mikhailovskaya, A.V., Levchenko, V.S., Kotov, A.D., Drits, A.M., and Portnoy, V.K., Formation of fine-grained structure and superplasticity in commercial aluminum alloy 1565ch, Met. Sci. Heat Treat., 2017, vol. 58, pp. 543–547. https://doi.org/10.1007/s11041-017-0051-y
Drits, A.M. and Ovchinnikov, V.V., Properties of welded joints of 1565h alloy sheets in combination with other aluminum alloys, Tsvetn. Met. (Moscow, Russ. Fed.), 2013, no. 11, pp. 84–90.
Belov, N.A., Naumova, E.A., and Akopyan, T.K., Evtekticheskie splavy na osnove alyuminiya: Novye sistemy legirovaniya (Eutectic Alloys Based on Aluminum: New Alloying Systems), Moscow: Ruda i Metally, 2016.
Belov, N.A., Naumova, E.A., and Akopyan, T.K., Eutectic alloys based on the Al–Zn–Mg–Ca system: microstructure, phase composition and hardening, Mater. Sci. Technol., 2017, vol. 33, no. 6, pp. 656–666. https://doi.org/10.1080/02670836.2016.1229847
Belov, N.A., Naumova, E.A., and Akopyan, T.K., Effect of calcium on structure, phase composition and hardening of Al–Zn–Mg alloys containing up to 12 wt % Zn, Mater. Res., 2015, vol. 18, no. 6, pp. 1384–1391. https://doi.org/10.1590/1516-1439.036415
Naumova, E.A., Belov, N.A., and Bazlova, T.A., Effect of heat treatment on structure and strengthening of cast eutectic aluminum alloy Al9Zn4Ca3Mg, Met. Sci. Heat Treat., 2015, vol. 57, nos. 5–6, pp. 274–280. https://doi.org/10.1007/s11041-015-9874-6
Naumova, E.A., Use of calcium in alloys: From modifying to alloying, Russ. J. Non-Ferrous Met., 2018, vol. 59, no. 3, pp. 284–298. https://doi.org/10.3103/S1067821218030100
Volkova, O.V., Dub, A.V., Rakoch, A.G., Gladkova, A.A., and Samoshina, M.E., Comparison of the tendency to pitting corrosion of casting of Al6Ca, Al1Fe, and Al6Ca1Fe experimental alloys and AK12M2 industrial alloy, Russ. J. Non-Ferrous Met., 2017, vol. 58, no. 6, pp. 644–648. https://doi.org/10.3103/S1067821217060153
Belov, N.A., Naumova, E.A., Ilyukhin, V.D., and Doroshenko, V.V., Structure and mechanical properties of Al–6% Ca–% Fe alloy foundry goods, obtained by die casting, Tsvetn. Met. (Moscow, Russ. Fed.), 2017, no. 3, pp. 69–75. https://doi.org/10.17580/tsm.2017.03.11
Belov, N.A., Akopyan, T.K., Mishurov, S.S., and Korotkova, N.O., Effect of Fe and Si on the microstructure and phase composition of the aluminium-calcium eutectic alloys, Non-Ferrous Met. (Moscow, Russ. Fed.), 2017, no. 2, pp. 37–42. https://doi.org/10.17580/nfm.2017.02.07
Shurkin, P.K., Belov, N.A., Musin, A.F., and Samoshina, M.E., Effect of calcium and silicon on the character of solidification and strengthening of the Al–8% Zn–3% Mg alloy, Phys. Met. Metallogr., 2020, vol. 121, pp. 135–142. https://doi.org/10.1134/S0031918X20020155
Huang, X., Pan, Q., Li, B., Yin, Z., Liu, Z., and Huang, Z., Effect of minor Sc on microstructure and mechanical properties of Al–Zn–Mg–Zr alloy metal-inert gas welds, J. Alloys Compd., 2015, vol. 629, pp. 197–207. https://doi.org/10.1016/j.jallcom.2014.11.227
Deng, Y., Peng, B., Xu, G., Pan, Q., Yin, Z., Ye, R., Wang, Y., and Lu, L., Effects of Sc and Zr on mechanical property and microstructure of tungsten inert gas and friction stir welded aerospace high strength Al–Zn–Mg alloys, Mater. Sci. Eng., A, 2015, vol. 639, pp. 500–513. https://doi.org/10.1016/j.msea.2015.05.052
Lei, X., Deng, Y., Yin, Z., Xu, G., and Peng, Y., Microstructure and properties of TIG/FSW welded joints of a new Al–Zn–Mg–Sc–Zr alloy, J. Mater. Eng. Perform., 2013, vol. 22, no. 9, pp. 2723–2729. https://doi.org/10.1007/s11665-013-0577-0
Belov, N.A., Alabin, A.N., and Matveeva, I.A., Optimization of phase composition of Al–Cu–Mn–Zr–Sc alloys for rolled products without requirement for solution treatment and quenching. J. Alloys Compd., 2014, vol. 583, pp. 206–213. https://doi.org/10.1016/j.jallcom.2013.08.202
Akopyan, T.K., Letyagin, N.V., and Doroshenko, V.V., Al–Ca–Ni–Ce-based aluminium matrix composites hardened with L12 phase nanoparticles without quenching, Tsvetn. Met. (Moscow, Russ. Fed.), 2018, no. 12, pp. 56–62. https://doi.org/10.17580/tsm.2018.12.08
Akopyan, T.K., Belov, N.A., Naumova, E.A., Letya-gin, N.V., and Sviridova, T.A., Al-matrix composite based on Al–Ca–Ni–La system additionally reinforced by L12 type nanoparticles, Trans. Nonferrous Met. Soc. China, 2020, vol. 30, no. 4, pp. 850–862. https://doi.org/10.1016/S1003-6326(20)65259-1
Akopyan, T.K., Belov, N.A., Latypov, R.A., Shurkin, P.K., and Karpova, Zh.A., RF Patent 2716568, 2020.
Glazoff, M.V., Khvan, A.V., Zolotorevsky, V.S., Belov, N.A., and Dinsdale, A.T., Casting Aluminum Alloys. Their Physical and Mechanical Metallurgy, Butterworth-Heinemann, 2018. https://doi.org/10.1016/B978-0-12-811805-4.00003-1
GOST (State Standard) no. 4784–2019: Aluminium and wrought aluminium alloys. Grades, Moscow: Standartinform, 2019.
Samiuddin, M., Li, J.L., Taimoor, M., Siddiqui, M.N., Siddiqui, S.U., and Xiong, J.T., Investigation on the process parameters of TIG-welded aluminum alloy through mechanical and microstructural characterization, Def. Technol., 2020. https://doi.org/10.1016/j.dt.2020.06.012
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Karpova, Z.A., Shurkin, P.K., Sivtsov, K.I. et al. Processability and Structure Formation of the Al–Zn–Mg–Ca–Fe–Zr–Sc Alloy upon Hot Rolling and TIG Welding. Russ. J. Non-ferrous Metals 62, 431–440 (2021). https://doi.org/10.3103/S106782122104009X
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DOI: https://doi.org/10.3103/S106782122104009X