Quasi-in situ immersion characterization of grain structures evolution revealing the corrosion resistance of Al-Zn-Mg alloys with various Sc additions

Abstract

Al-Zn-Mg alloys have been investigated for the effect of Sc additions on corrosion resistance. The addition of Sc to Al-Zn-Mg alloys can more effectively retard recrystallisation during heat treatment and improve mechanical properties. Sc-added alloys show significant discontinuity in grain boundary precipitation. In addition, the distribution spacing of η precipitates at the grain boundary is the largest in the alloy with Sc content of 0.29 wt.%. The exfoliation corrosion test and microstructural recrystallisation analysis show the inhibitory effect of Sc addition on recrystallisation and hence the improvement in corrosion resistance. In-situ immersion corrosion results indicated that the uncorroded texture in Al-Zn-Mg alloy with 0.29 wt.% Sc content first showed a rapid decrease and then a rapid increase. The addition of Sc to Al-Zn-Mg alloy plays an important role in improving the surface texture and increasing the corrosion resistance in the early stages of corrosion.

Keywords

Al-Zn-Mg alloy / corrosion resistance / exfoliation corrosion / microstructures / textures

References

[1] LiuY, JiangD, LiB, et al. . Effect of cooling aging on microstructure and mechanical properties of an Al-Zn-Mg-Cu alloy [J]. Materials & Design, 2014, 57: 79-86

[2] LiL, YuanT, DengC, et al. . Effects of aging treatment on microstructure and mechanical properties of selective laser melted Al-Zn-Mg-Cu-Si-Zr alloys [J]. Journal of Alloys and Compounds, 2022, 890: 161810

[3] XuY, ZhangZ, GaoZ, et al. . Effect of main elements (Zn, Mg and Cu) on the microstructure, castability and mechanical properties of 7xxx series aluminum alloys with Zr and Sc [J]. Materials Characterization, 2021, 182111559

[4] OdusoteJ K, AdelekeA A, MurainaS A, et al. . Magnesium inclusion effect on Al-Zn-Cu alloys: A study on microstructure and mechanical properties [J]. Materials Today: Proceedings, 2021, 465914-5921

[5] ZhongH, LiS, WuJ, et al. . Effects of retrogression and re-aging treatment on precipitation behavior, mechanical and corrosion properties of a Zr+Er modified Al-Zn-Mg-Cu alloy [J]. Materials Characterization, 2022, 183: 111617

[6] RometschP A, ZhangY, KnightS. Heat treatment of 7xxx series aluminium alloys—Some recent developments [J]. Transactions of Nonferrous Metals Society of China, 2014, 24(7): 2003-2017

[7] AzarniyaA, TaheriA K, TaheriK K. Recent advances in ageing of 7xxx series aluminum alloys: A physical metallurgy perspective [J]. Journal of Alloys and Compounds, 2019, 781945-983

[8] WenK, LiX, XiongB, et al. . Influence of minor Sc additions on grain refinement and microstructure characteristics of a high Zn-containing Al-Zn-Mg-Cu-Zr alloy [J]. Journal of Central South University, 2022, 29(3): 780-794

[9] PengN, ZhanL, MaB, et al. . Creep aging behavior and performance of Al-Zn-Mg-Cu alloys under different parameters in retrogression aging treatment [J]. Journal of Central South University, 2022, 29(3): 986-998

[10] HeK, LiQ, LiuS, et al. . Influence of pre-stretching on quench sensitive effect of high-strength Al-Zn-Mg-Cu-Zr alloy sheet [J]. Journal of Central South University, 2021, 28(9): 2660-2669

[11] ZhangQ, SunF, LiuM, et al. . Optimizing microstructure and mechanical properties of heat-treated Al-Zn-Mg-Cu alloy by indirect hot deformation technology [J]. Journal of Central South University, 2022, 29(11): 3544-3556

[12] AamirM, GiasinK, Tolouei-RadM, et al. . A review: Drilling performance and hole quality of aluminium alloys for aerospace applications [J]. Journal of Materials Research and Technology, 2020, 9(6): 12484-12500

[13] EntringerJ, MeisnarM, ReimannM, et al. . The effect of grain boundary precipitates on stress corrosion cracking in a bobbin tool friction stir welded Al-Cu-Li alloy [J]. Materials Letters: X, 2019, 2: 100014

[14] TsaiS P, MakineniS K, GaultB, et al. . Precipitation formation on ∑ 5 and ∑ 7 grain boundaries in 316L stainless steel and their roles on intergranular corrosion [J]. Acta Materialia, 2021, 210116822

[15] YingT, GuL, TangX, et al. . Effect of Sc microalloying on microstructure evolution and mechanical properties of extruded Al-Zn-Mg-Cu alloys [J]. Materials Science and Engineering A, 2022, 831142197

[16] JonesM J, HumphreysF J. Interaction of recrystallization and precipitation: The effect of Al₃Sc on the recrystallization behaviour of deformed aluminium [J]. Acta Materialia, 2003, 51(8): 2149-2159

[17] DavydovV G, RostovaT D, ZakharovV V, et al. . Scientific principles of making an alloying addition of scandium to aluminium alloys [J]. Materials Science and Engineering A, 2000, 280(1): 30-36

[18] LiZ, JiangH, WangY, et al. . Effect of minor Sc addition on microstructure and stress corrosion cracking behavior of medium strength Al-Zn-Mg alloy [J]. Journal of Materials Science & Technology, 2018, 34(7): 1172-1179

[19] LiuL, JiaY, JiangJ, et al. . The effect of Cu and Sc on the localized corrosion resistance of Al-Zn-Mg-X alloys [J]. Journal of Alloys and Compounds, 2019, 7991-14

[20] ZhangH, ZhuH, NieX, et al. . Effect of Zirconium addition on crack, microstructure and mechanical behavior of selective laser melted Al-Cu-Mg alloy [J]. Scripta Materialia, 2017, 134: 6-10

[21] MartinA, VilanovaM, GilE, et al. . Influence of the Zr content on the processability of a high strength Al-Zn-Mg-Cu-Zr alloy by laser powder bed fusion [J]. Materials Characterization, 2022, 183: 111650

[22] FangH C, ChaoH, ChenK H. Effect of Zr, Er and Cr additions on microstructures and properties of Al-Zn-Mg-Cu alloys [J]. Materials Science and Engineering A, 2014, 61010-16

[23] LefebvreW, DanoixF, HallemH, et al. . Precipitation kinetic of Al₃(Sc, Zr) dispersoids in aluminium [J]. Journal of Alloys and Compounds, 2009, 470(1–2): 107-110

[24] DevS, StuartA A, KumaarR C R D, et al. . Effect of scandium additions on microstructure and mechanical properties of Al-Zn-Mg alloy welds [J]. Materials Science and Engineering A, 2007, 467(1–2): 132-138

[25] Booth-MorrisonC, DunandD C, SeidmanD N. Coarsening resistance at 400 °C of precipitation-strengthened Al-Zr-Sc-Er alloys [J]. Acta Materialia, 2011, 59(18): 7029-7042

[26] MukhopadhyayA K, KumarA, RaveendraS, et al. . Development of grain structure during superplastic deformation of an Al-Zn-Mg-Cu-Zr alloy containing Sc [J]. Scripta Materialia, 2011, 64(5): 386-389

[27] SinghA P, SrivastavaC. Understanding the nonmonotonic variation in the corrosion rate of Sn-Ni coatings with Ni addition by the analysis of texture and grain boundary constitution of the matrix phase and spatial distribution of the intermetallic phase in the coating microstructure [J]. Corrosion Science, 2023, 211: 110787

[28] SinghA P, SrivastavaC. Effect of selective atomic clustering, surface texture and grain boundary constitution on the corrosion behaviour of electrodeposited Sn-xBi coatings [J]. Corrosion Science, 2023, 215111039

[29] GerashiE, AlizadehR, LangdonT G. Effect of crystallographic texture and twinning on the corrosion behavior of Mg alloys: A review [J]. Journal of Magnesium and Alloys, 2022, 10(2): 313-325

[30] TighiouaretS, HannaA, AzzeddineH, et al. . On the evolution of microstructure, texture and corrosion behavior of a hot-rolled and annealed AZ31 alloy [J]. Materials Chemistry and Physics, 2021, 267124598

[31] FangH, LiuH, YanY, et al. . Evolution of texture, microstructure, tensile strength and corrosion properties of annealed Al-Mg-Sc-Zr alloys [J]. Materials Science and Engineering A, 2021, 804140682

[32] YuanM, DengY, LinS, et al. . Effect of the cross accumulative roll bonding on the corrosion behaviour of AA6082/AA7204 composite sheets [J]. Metals and Materials International, 2021, 27(9): 3709-3719

[33] YeJ, PanQ, LiuB, et al. . Effects of co-addition of minor Sc and Zr on aging precipitates and mechanical properties of Al-Zn-Mg-Cu alloys [J]. Journal of Materials Research and Technology, 2023, 222944-2954

[34] ZenerC. Grains, phase, and interfaces: An interpretation of microstructure[J]. Transactions of the Institution of Mining and Metallurgy Section A, 1948, 175: 15-51

[35] ZhaoJ, DengY, TangJ, et al. . Effect of gradient grain structures on corrosion resistance of extruded Al-Zn-Mg-Cu alloy [J]. Journal of Alloys and Compounds, 2020, 832: 154911

[36] XiaoT, DengY, YeL, et al. . Effect of three-stage homogenization on mechanical properties and stress corrosion cracking of Al-Zn-Mg-Zr alloys [J]. Materials Science and Engineering A, 2016, 675280-288