Microstructure and mechanical properties of the welding joint filled with microalloying 5183 aluminum welding wires

Abstract

In this study, 7A52 aluminum alloy sheets of 4 mm in thickness were welded by tungsten inert gas welding using microalloying welding wires containing traces of Zr and Er. The influence of rare earth elements Zr and Er on the microstructure and mechanical properties of the welded joints was analyzed by optical microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, hardness testing, and tensile mechanical properties testing. Systematic analyses indicate that the addition of trace amounts of Er and Zr leads to the formation of fine Al₃Er, Al₃Zr, and Al₃(Zr,Er) phases that favor significant grain refinement in the weld zone. Besides, the tensile strength and hardness of the welded joints were obviously improved with the addition of Er and Zr, as evidenced by the increase in tensile strength and elongation by 40 MPa and 1.4%, respectively, and by the welding coefficient of 73%.

Keywords

aluminum alloys / inert gas welding / rare earth elements / microalloying / joints / microstructure / mechanical properties

References

[1] Dixit M, Mishra RS, Sankaran KK. Structure-property correlations in Al 7050 and Al 7055 high-strength aluminum alloys. Mater. Sci. Eng. A, 2008, 478(1–2): 163.

[2] Yan LM, Shen J, Li JP, Li ZB, Yan XD. Deformation behavior and microstructure of an Al-Zn-Mg-Cu-Zr alloy during hot deformation. Int. J. Miner. Metall. Mater., 2010, 17(1): 46.

[3] Yang C, Guo WM, Zhang HX, Qiu R, Hou J, Fu YB. Study on the corrosion behavior of 7A52 Al alloy welded joint by electrochemical method. Int. J. Electrochem. Sci., 2013, 8(7): 9308

[4] Yang DX, Li XY, He DY, Hang H, Zhang L. Study on microstructure and mechanical properties of Al-Mg-Mn-Er alloy joints welded by TIG and laser beam. Mater. Des., 2012, 40, 117.

[5] Sato YS, Arkom P, Kokawa H, Nelson TW, Steel RJ. Effect of microstructure on properties of friction stir welded Inconel alloy 600. Mater. Sci. Eng. A, 2008, 477(1–2): 250

[6] Norman AF, Hyde K, Costello F, Thompson S, Birley S, Prangnell PB. Examination of the effect of Sc on 2000 and 7000 series aluminium alloy castings: for improvements in fusion welding. Mater. Sci. Eng. A, 2003, 354(1–2): 188.

[7] Dev S, Stuart AA, Kumaar RCRD, Murty BS, Rao KP. Effect of scandium additions on microstructure and mechanical properties of Al-Zn-Mg alloy welds. Mater. Sci. Eng. A, 2007, 467(1–2): 132.

[8] Booth-Morrison C, Dunand DC, Seidman DN. Coarsening resistance at 400°C of precipitation-strengthened Al-Zr-Sc-Er alloys. Acta Mater., 2011, 59(18): 7029.

[9] Mukhopadhyay AK, Kumar A, Raveendra S, Samajdar I. Development of grain structure during superplastic deformation of an Al-Zn-Mg-Cu-Zr alloy containing Sc. Scripta Mater., 2011, 64(5): 386.

[10] Dalen ME v, Gyger T, Dunand DC, Seidman DN. Effects of Yb and Zr microalloying additions on the microstructure and mechanical properties of dilute Al-Sc alloys. Acta Mater., 2011, 59(20): 7615.

[11] Knipling KE, Seidman DN, Dunand DC. Ambient- and high-temperature mechanical properties of isochronally aged Al-0.06Sc, Al-0.06Zr and Al-0.06Sc-0.06Zr (at.%) alloys. Acta Mater., 2011, 59(3): 943.

[12] Liu ZX, Li ZJ, Wang MX, Weng YG. Effect of complex alloying of Sc, Zr and Ti on the microstructure and mechanical properties of Al-5Mg alloys. Mater. Sci. Eng. A, 2008, 483–484, 120

[13] Singh V, Prasad KS, Gokhale AA. Effect of minor Sc additions on structure, age hardening and tensile properties of aluminium alloy AA8090 plate. Scripta Mater., 2004, 50(6): 903.

[14] Halevy I, Beeri O, Hu J. Sc-strengthened commercial purity aluminum under high pressure. J. Mater. Sci., 2010, 45(3): 589.

[15] Fuller CB, Krause AR, Dunand DC, Seidman DN. Microstructure and mechanical properties of a 5754 aluminum alloy modified by Sc and Zr additions. Mater. Sci. Eng. A, 2002, 338(1–2): 8.

[16] Filatov YA, Yelagin VI, Zakharov VV. New Al-Mg-Sc alloys. Mater. Sci. Eng. A, 2000, 280(1): 97.

[17] Sawtell RR, Jensen CL. Mechanical properties and microstructures of Al-Mg-Sc alloys. Metall. Trans. A, 1990, 21(1): 421.

[18] Lapasset G, Girard Y, Campagnac MH, Boivin D. Investigation of the microstructure and properties of a friction stir welded Al-Mg-Sc alloy. Mater. Sci. Forum, 2003, 426–432, 2987.

[19] Lee S, Utsunomiya A, Akamatsu H, Neishi K, Furukawa M, Horita Z, Langdon TG. Influence of scandium and zirconium on grain stability and superplastic ductilities in ultrafine-grained Al-Mg alloys. Acta Mater., 2002, 50(3): 553.

[20] Fazeli F, Poole WJ, Sinclair CW. Modeling the effect of Al₃Sc precipitates on the yield stress and work hardening of an Al-Mg-Sc alloy. Acta Mater., 2008, 56(9): 1909.

[21] Karnesky RA, van Dalen ME, Dunand DC, Seidman DN. Effects of substituting rare-earth elements for scandium in a precipitation-strengthened Al-0.08at.% Sc alloy. Scripta Mater., 2006, 55(5): 437.

[22] Nie ZR, Jin TN, Zou JX, Fu JB, Yang JJ, Zuo TY. Development on research of advanced rare-earth aluminum alloy. Trans. Nonferrous Met. Soc. China, 2003, 13(3): 509

[23] Nie ZR, Jin TN, Fu JB, Xu GF, Yang JJ, Zhou JX, Zuo TY. Research on rare earth in aluminum. Mater. Sci. Forum, 2002, 396–402, 1731.

[24] Wen SP, Xing ZB, Huang H, Li BL, Wang W, Nie ZR. The effect of erbium on the microstructure and mechanical properties of Al-Mg-Mn-Zr alloy. Mater. Sci. Eng. A, 2009, 516(1–2): 42.

[25] Wu ZG, Song M, He YH. Effects of Er on the microstructure and mechanical properties of an as-extruded Al-Mg alloy. Mater. Sci. Eng. A, 2009, 504(1–2): 183.

[26] Yin ZM, Fang JF, Huang JW, Nie B, Shan CZ, Guo JL, Wang L. Effects of aging treatment on intercrystalline corrosion and exfoliation corrosion behavior of 7A52 aluminum alloy. J. Cent. South Univ. Sci. Technol., 2007, 38(4): 617