Effects of Sc and Zr microalloying on the microstructure and mechanical properties of high Cu content 7xxx Al alloy

Abstract

The effects of Sc and Zr microalloying on the microstructure and mechanical properties of a 7xxx Al alloy with high Cu content (7055) during casting, deformation, and heat treatment were investigated. The addition of Sc and Zr not only refined the grains but also transformed the θ-phase into the W-phase in the 7055 alloy. Minor Sc and Zr additions enhanced the hardness and yield strength of the 7055-T6 alloy by strengthening the grain boundaries and Al₃(Sc,Zr) precipitates. However, a further increase in the Sc and Zr fractions did not refine the grains but instead resulted in the formation of the large-sized W-phase and primary coarse Al₃(Sc,Zr) phase and subsequently deteriorated the mechanical properties of the alloys. The 7055 alloy with 0.25Sc addition exhibited the best mechanical property among the prepared alloys.

Keywords

aluminum alloys / microstructural evolution / mechanical property / grain refinement

References

[1] Buranova Y, Kulitskiy V, Peterlechner M, Mogucheva A, Kaibyshev R, Divinski SV, Wilde G. Al₃(Sc,Zr)-based precipitates in Al-Mg alloy: Effect of severe deformation. Acta Mater., 2017, 124, 210.

[2] Liu T, He CN, Li G, Meng X, Shi CS, Zhao NQ. Microstructural evolution in Al-Zn-Mg-Cu-Sc-Zr alloys during short-time homogenization. Int. J. Miner. Metall. Mater., 2015, 22, 516.

[3] Li JH, Wiessner M, Albu M, Wurster S, Sartory B, Hofer F, Schumacher P. Correlative characterization of primary Al₃(Sc,Zr) phase in an Al-Zn-Mg based alloy. Mater. Charact., 2015, 102, 62.

[4] Zhang M, Liu T, He CN, Ding J, Liu EZ, Shi CS, Li JJ, Zhao NQ. Evolution of microstructure and properties of Al-Zn-Mg-Cu-Sc-Zr alloy during aging treatment. J. Alloys Compd., 2016, 658, 946.

[5] Duan YL, Xu GF, Tang L, Liu Y, Xu JW, Deng Y, Yin ZM. Excellent high strain rate super plasticity of Al-Mg-Sc-Zr alloy sheet produced by an improved asymmetrical rolling process. J. Alloys Compd., 2017, 715, 311.

[6] Li B, Pan QL, Huang X, Yin ZM. Microstructures and properties of Al-Zn-Mg-Mn alloy with trace amounts of Sc and Zr. Mater. Sci. Eng. A, 2014, 616, 219.

[7] Huang X, Pan QL, Li B, Liu ZM, Huang ZQ, Yin ZM. Microstructure, mechanical properties and stress corrosion cracking of Al-Zn-Mg-Zr alloy sheet with trace amount of Sc. J. Alloys Compd., 2015, 650, 805.

[8] Li G, Zhao NQ, Liu T, Li JJ, He CN, Shi CS, Liu EZ, Sha JW. Effect of Sc/Zr ratio on the microstructure and mechanical properties of new type of Al-Zn-Mg-Sc-Zr alloys. Mater. Sci. Eng. A, 2014, 617, 219.

[9] Deng Y, Peng B, Xu GF, Pan QL, Yin ZM, Ye R, Wang YJ, Lu LY. 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, 639, 500.

[10] Liu CY, Zhang B, Ma ZY, Teng GB, Wei LL, Zhou WB, Zhang XY. Effects of pre-aging and minor Sc addition on the microstructure and mechanical properties of friction stir processed 7055 Al alloy. Vacuum, 2018, 149, 106.

[11] Chen Y, Liu CY, Zhang B, Ma ZY, Zhou WB, Jiang HJ, Huang HF, Wei LL. Effects of friction stir processing and minor Sc addition on the microstructure, me chanical properties, and damping capacity of 7055 Al alloy. Mater. Charact., 2018, 135, 25.

[12] Teng GB, Liu CY, Ma ZY, Zhou WB, Wei LL, Chen Y, Li J, Mo YF. Effects of minor Sc addition on the microstructure and mechanical properties of 7055 Al alloy during aging. Mater. Sci. Eng. A, 2018, 713, 61.

[13] Liu CY, Zhang B, Ma ZY, Jiang HJ, Zhou WB. Effect of Sc addition, friction stir processing, and T6 treatment on the damping and mechanical properties of 7055 Al alloy. J. Alloys Compd., 2019, 772, 775.

[14] Zhang ZH, Xue J, Jiang YB, Jin F. Effect of pre-annealing treatment on the microstructure and mechanical properties of extruded Al-Zn-Mg-Cu alloy bars. Int. J. ^Miner. Metall. Mater., 2017, 24, 1284.

[15] Cai CB, Xu XJ, Huang JD, Ju SH, Ding Q, Wang CS. Effect of pre-recovery on microstructure and properties of rolled Al-12.18Zn-3.31Mg-1.43Cu-0.20Zr-0.04Sr aluminum alloy. Int. J. ^Miner. Metall. Mater., 2019, 26, 241.

[16] Zheng CB, Yan BH, Zhang K, Yi G. Electrochemical investigation on the hydrogen permeation behavior of 7075-T6 Al alloy and its influence on stress corrosion cracking. Int. J. ^Miner. Metall. Mater., 2015, 22, 729.

[17] Wang D, Ma ZY, Gao ZM. Effects of severe cold rolling on tensile properties and stress corrosion cracking of 7050 aluminum alloy. Mater. Chem. Phys., 2009, 117, 228.

[18] Xie JF, Zhu YL, Bian FL, Liu C. Dynamic recovery and recrystallization mechanisms during ultrasonic spot welding of Al-Cu-Mg alloy. Mater. Charact., 2017, 132, 145.

[19] Moghanaki SK, Kazeminezhad M, Logé R. Effect of concurrent precipitation on the texture evolution during continuous heating of multi directionally forged solution treated Al-Cu-Mg alloy. Mater. Charact., 2017, 131, 399.

[20] Zuiko I, Kaibyshev R. Deformation structures and strengthening mechanisms in an Al-Cu alloy subjected to extensive cold rolling. Mater. Sci. Eng. A, 2017, 702, 53.

[21] Yu K, Li WX, Li SR, Zhao J. Mechanical properties and microstructure of aluminum alloy 2618 with Al₃(Sc,Zr) phases. Mater. Sci. Eng. A, 2004, 368, 88.

[22] Samuel AM, Alkahtani SA, Doty HW, Samuel FH. Role of Zr and Sc addition in controlling the microstructure and tensile properties of aluminum-copper based alloys. Mater. Des., 2015, 88, 1134.

[23] Belov NA, Alabin AN, Matveeva IA. 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, 583, 206.

[24] Jia M, Zheng ZQ, Gong Z. Microstructure evolution of the 1469 Al-Cu-Li-Sc alloy during. J. Alloys Compd., 2014, 614, 131.

[25] Gazizov M, Teleshov V, Zakharov V, Kaibyshev R. Solidification behaviour and the effects of homogenisation on the structure of an Al-Cu-Mg-Ag-Sc alloy. J. Alloys Compd., 2011, 509, 9497.

[26] Li YT, Liu ZY, Xia QK, Liu YB. Grain refinement of the Al-Cu-Mg-Ag alloy with Er and Sc additions. Metall. Mater. Trans. A, 2007, 38, 2853.

[27] Chen BA, Pan L, Wang RH, Liu G, Cheng PM, Xiao L, Sun J. Effect of solution treatment on precipitation behaviors and age hardening response of Al-Cu alloys with Sc addition. Mater. Sci. Eng. A, 2011, 530, 607.

[28] Jiang L, Li JK, Liu G, Wang RH, Chen BA, Zhang JY, Sun J, Yang MX, Yang G, Yang J, Cao XZ. Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al-Cu alloys with minor Sc addition. Mater. Sci. Eng. A, 2015, 637, 139.

[29] Liu SD, Zhang XM, Chen MA, You JH. Influence of aging on quench sensitivity effect of 7055 aluminum alloy. Mater. Charact., 2008, 59, 53.

[30] Zuo JR, Hou LG, Shi JT, Cui H, Zhuang LZ, Zhang JS. The mechanism of grain refinement and plasticity enhancement by an improved thermomechanical treatment of 7055 Al alloy. Mater. Sci. Eng. A, 2017, 702, 42.

[31] Chen YX, Yang YQ, Feng ZQ, Huang B, Luo X. Surface gradient nanostructures in high speed machined 7055 aluminum alloy. J. Alloys Compd., 2017, 726, 367.

[32] She H, Shu D, Wang J, Sun BD. Influence of mul-ti-microstructural alterations on tensile property inhomogene-ity of 7055 aluminum alloy medium thick plate. Mater. Cha-ract., 2016, 113, 189.

[33] Zhao YH, Liao XZ, Cheng S, Ma E, Zhu YT. Simultaneously increasing the ductility and strength of nano-structured alloys. Adv. Mater., 2006, 18, 2280.