Microstructure evolution of semi-solid billet fabricated by semi-solid isothermal heat treatment of wrought AlSi7Mg aluminum alloy

Microstructure evolution of semi-solid billet fabricated by semi-solid isothermal heat treatment of wrought AlSi7Mg aluminum alloy

JIANG Jufu, SONG Tao, WANG Ying, ZHANG Ying, ZHU Liang, DONG Jian

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Abstract: In this paper, the as-cast AlSi7Mg aluminum alloy billet was upsetted above recrystallization temperature to obtain wrought aluminum alloy with 50% deformation degree, and semi-solid isothermal treatment method was employed to achieve semi-solid billet of the wrought AlSi7Mg aluminum alloy. The microstructure observation and evolution law were investigated via optical microscope and scanning electron microscope. The results show that the primary α-Al phase can be changed from dendrite to spherical structure by semi-solid isothermal treatment of the wrought alloy (SSITWA). The complete transformation of the primary α-Al phase from dendrite to spherical structure can be achieved by increasing the isothermal temperature and prolongation of holding time. However, when the holding time is too long, the spheroidized grains will grow abnormally and eventually become irregularly shaped grains. High isothermal temperature can increase the primary α-Al size and reduce the time of dendrite to spheroidal grains. The average grain size of AlSi7Mg aluminum alloy semi-solid billet fabricated by SSITWA varies in a range of from 15 μm to 65 μm when the temperature and holding time change. The content of Al and Si elements in primary α-Al phase is obviously higher than that in liquid eutectic phase consisting of Al and Si elements, and the distribution of Mg element is uniform in the microstructure of semi-solid billet fabricated by SSITWA.

Keywords
Semi-Solid, Isothermal Heat Treatment, Microstructure, AlSi7Mg Aluminum Alloy

Published online 9/15/2024, 18 pages
Copyright © 2024 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: JIANG Jufu, SONG Tao, WANG Ying, ZHANG Ying, ZHU Liang, DONG Jian, Microstructure evolution of semi-solid billet fabricated by semi-solid isothermal heat treatment of wrought AlSi7Mg aluminum alloy, Materials Research Proceedings, Vol. 44, pp 718-735, 2024

DOI: https://doi.org/10.21741/9781644903254-77

The article was published as article 77 of the book Metal Forming 2024

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

References
[1] H. Yang, W.T. Tian, Metallurgical Structure of A356 Alloy Solidified by Mechanical Stirring, Solid State Phenom. 285 (2019) 183-188.
[2] Y.E. Albarbary, R. Afify, E.H. Mansour, T.S. Mahmoud, M. Khedr, The effect of pre-drilling on the characteristics of friction drilled A356 cast aluminum alloy, J. Manuf. Process. 82 (2022) 646-656. https://dx.doi.org/10.1016/j.jmapro.2022.08.040
[3] N.Z. Liu, B. Jiang, Y.Wang, Z.S.Ji, M.L.Hu, H.Y. Xu, Influence of trace amount chromium on microstructure and corrosion behavior of A356-5vol.%TiB2 alloy, Mater. Lett. 314 (2022) 131798.
[4] S.K. Thandalam, J. Nampoothiri, S. Shalini, T. Thankachan, Microstructure and Wear Characteristics of Nano Y2O3 Particles Reinforced A356 Alloy Composites Synthesized Through Novel Ultrasonic Assisted Stir Casting Technique, Trans. Indian Inst. Met. 75 (2022) 417-426. https://dx.doi.org/10.1007/s12666-021-02424-1
[5] P. Nelaturu, S. Jana, R.S. Mishra, G. Grant, B.E. Carlson, Effect of temperature on the fatigue cracking mechanisms in A356 Al alloy, Mater. Sci. Eng. A 780 (2020) 139175. https://doi.org/10.1016/j.msea.2020.139175
[6] V.H. Carneiro, J. Grilo, D. Soares, I. Duarte, H. Puga, The Influence of Precipitation Hardening on the Damping Capacity in Al-Si-Mg Cast Components at Different Strain Amplitudes, Metals 12 (2022) 804. https://dx.doi.org/10.3390/met12050804
[7] S. Zhang, L. Bo, L. Wang, Y.B. Hou, D. Zhao, Effects of thermal-rate treatment and modification of Ce on the microstructure and properties of A356 alloys, J. Phys.: Conf. Ser. 1885 (2021) 022064. https://dx.doi.org/10.1088/1742-6596/1885/2/022064
[8] M. Varmazyar, S. Yousefzadeh, M.M. Sheikhi, Effect of Ni on Microstructure and Creep Behavior of A356 Aluminum Alloy, Met. Mater. Int. 28 (2022) 579–588. https://dx.doi.org/10.1007/s12540-020-00892-6
[9] G.F. Xiao, J.F. Jiang, Y.Z. Liu, Y. Wang, B.Y. Guo, Recrystallization and microstructure evolution of hot extruded 7075 aluminum alloy during semi-solid isothermal treatment, Mater. Charact. 156 (2019) 109874.
[10] J. Liu, Y.S. Cheng, S.W.N. Chan, D. Sung, Microstructure and mechanical properties of 7075 aluminum alloy during complex thixoextrusion, Trans. Nonferrous Met. Soc. China 30 (2020) 3173-3182. https://dx.doi.org/10.1016/S1003-6326(20)65452-8
[11] Y.F. Wang, S.D. Zhao, Y. Guo, K.X. Liu, S.Q. Zheng, Deformation Characteristics and Constitutive Equations for the Semi-Solid Isothermal Compression of Cold Radial Forged 6063 Aluminium Alloy, Materials 14 (2021) 194. https://doi.org/10.3390/ma14010194
[12] H. Negini, A. Rezaei, M. Hajisafari, H. Momeni, Effects of semi-solid thermomechanical processing on microstructure and mechanical properties of Al 2024, Trans. Indian Inst. Met. 72 (2019) 1201-1209. https://dx.doi.org/10.1007/s12666-019-01608-0
[13] Q. Gao, B. Yang, G.S. Gan, Y.J. Zhong, L. Sun, W.Y. Zhai, W. Qiang, S.Q. Wang, Y.X. Lu, Microstructure and Wear Resistance of TiB2/7075 Composites Produced via Rheocasting, Metals 10 (2020) 1068. https://doi.org/10.3390/met10081068
[14] Y.Z. Liu, J.F. Jiang, Y. Zhang, M.J. Huang, Y. Wang, Semi-solid compression of 2A14 alloy with high solid fraction: rheology, constitutive equation and microstructure, J. Mater. Sci. 57 (2022) 16507–16527. https://dx.doi.org/10.1007/s10853-022-07656-0
[15] Y. Liu, M.Q. Gao, Y. Fu, W.R . Li, P. Yang, R.G. Guan, Microstructure Evolution and Solidification Behavior of a Novel Semi-Solid Alloy Slurry Prepared by Vibrating Contraction Inclined Plate, Metals 11 (2021) 1810. https://doi.org/10.3390/met11111810
[16] Y.F. Wang, Y. Guo, S.D. Zhao, Effects of Process Parameters on the Microstructure and Hardness of Semi-Solid AlSi9Mg Aluminum Alloy Prepared by RAP Process, Mater. Trans. 61 (2020) 1731-1739. https://dx.doi.org/10.2320/matertrans.MT-M2020088
[17] M. Jahanbakhshi, S. Nourouzi, R. Naseri, K. Esfandiari, Investigation of Simultaneous Effects of Cooling Slope Casting and Mold Vibration on Mechanical and Microstructural Properties of A356 Aluminum Alloy, Met. Mater. Int. 28 (2022) 1508-1516. https://ui.adsabs.harvard.edu/link_gateway/2022MMI….28.1508J/doi:10.1007/s12540-021-01056-w
[18] L.J. Cao, G.R. Ma, C.X. Wang, Z.J. Chen, J.H. Zhang, Effect of compression ratio on microstructure evolution of Mg–10%Al–1%Zn–1%Si alloy prepared by SIMA process, Trans. Nonferrous Met. Soc. China 31 (2021) 2597-2605. https://doi.org/10.1016/S1003-6326(21)65678-9
[19] J.F. Jiang, Y.Z. Liu, G.F. Xiao, Y. Wang, Thixoforming of Semisolid Slurry with High Fraction Solid Fabricated by Partial Melting of Commerical Wrought Aluminum Alloys, Solid State Phenom. 285 (2019) 210-218.
[20] T.Y. Guan, Z.F. Zhang, M. He, Y.L. Bai, P. Wang, Effects of Annular Electromagnetic Stirring Melt Treatment on Microstructure and Mechanical Properties of 7050 Rheo-Casting, Solid State Phenom. 285 (2019) 219-223.
[21] W.C. Liu, Y. Sun, C. Deng, L.X. Hu, S.J. Yuan, J.Y. Shen, F. Gao, M.Y. Ba, Cu strengthened Al-Si-Cu semi-solid billet fabricated by liquid phase reaction sintering, Mater. Charact. 188 (2022) 11925.
[22] Z.X. Zhang, T.J. Chen, H. Xue, G.L. Bi, Y. Ma, R.G. Guan, Microstructure Evolution of an Al-Si Alloy During Shear-vibration Coupling Sub-rapid Solidification and the Effects of Processing Parameters, Int. J. Metalcast. 17 (2022). https://dx.doi.org/10.1007/s40962-022-00809-6
[23] L.J. Yu, H. Yan, L.X. Xu, L.J. Zhang, Z.B. Liu, Rheological Research of the Semisolid ADC12 Slurry Prepared with High-Energy Ultrasound and Pr/Ce Addition, Trans. Indian Inst. Met. 75 (2022) 495-502.
[24] J.F. Jiang, Y.H. Zhang, Y.Z. Liu, Y. Wang, G.F. Xiao, Y. Zhang, Research on AlSi7Mg Alloy Semi-solid Billet Fabricated By RAP, Acta Metall. Sin. 57 (2021) 703-716. https://doi.org/10.11900/0412.1961.2020.00254
[25] P.K. Seo, C.G. Kang, The effect of raw material fabrication process on microstructural characteristics in reheating process for semi-solid forming, J. Mater. Process. Technol. 162-163 (2005) 402-409. https://doi.org/10.1016/j.jmatprotec.2005.02.012
[26] Z. Liu, K. Cao, H.B. Xu, M.Y. Huang, Evolution Characteristics of Primary Phase in A356 Al Alloy during Isothermal Holding in Solid-Liquid Phase Region, Adv. Mater. Res. 421 (2012) 39-42. https://dx.doi.org/10.4028/www.scientific.net/AMR.421.39
[27] S.B. Hassas Irani, A. Zarei-Hanzaki, B. Bazaz, A.A. Roostaei, Microstructure evolution and semi-solid deformation behavior of an A356 aluminum alloy processed by strain induced melt activated method, Mater. Des. 46 (2013) 579-587. https://dx.doi.org/10.1016/j.matdes.2012.10.041
[28] W. Khalifa, S. El-Hadad, Y. Tsunekawa, Microstructure characteristics and tensile property of ultrasonic treated-thixocast A356 alloy, Trans. Nonferrous Met. Soc. China 25 (2015) 3173-3180. https://doi.org/10.1016/S1003-6326(15)63949-8
[29] A. Mahdavi, M. Bigdeli, M. Hajian Heidary, F. Khomamizadeh, Study of Microstructural Evolution and Phase’s Morphology after Partial Remelting in A356 Alloy, Solid State Phenom. 141-143 (2008) 367-372. https://dx.doi.org/10.4028/www.scientific.net/SSP.141-143.367
[30] H. Arami, R. Khalifehzadeh, H. Keyvan, F. Khomamizadeh, Effect of predeformation and heat treatment conditions in the SIMA process on microstructural and mechanical properties of A319 aluminum alloy, J. Alloy. Compd. 468 (2009) 130-135. https://dx.doi.org/10.1016/j.jallcom.2008.01.020
[31] K. Wang, Z.M. Zhang, H. Wen, D. Xia, W.J. Sun, Microstructural evolution of a fine-grained 7075Al alloy processed by friction stir process during partial remelting, Mater. Charact. 121 (2016) 1-8. https://doi.org/10.1016/j.matchar.2016.09.029
[32] S. Ashouri, M. Nili-Ahmadabadi, M. Moradi, M. Iranpour, Semi-solid microstructure evolution during reheating of aluminum A356 alloy deformed severely by ECAP, J. Alloy. Compd. 466 (2008) 67-72. https://doi.org/10.1016/j.jallcom.2007.11.010
[33] Y. Hu, F. Liu, L.Z. Zhao, Y.C. Tang, H.T. Jiao, Microstructural Evolution and Mechanical Properties of Semi-Solid Al15Mg45Li39Ca0.5Si0.5 Light-Weight High Entropy Alloys Fabricated by Isothermal Heat Treatment, Met. Mater. Int. 29 (2023) 1489-1497. https://ui.adsabs.harvard.edu/link_gateway/2023MMI….29.1489H/doi:10.1007/s12540-022-01303-8
[34] C.P. Wang, Z.J. Tang, H.S. Mei, L. Wang, R.Q. Li, D.F. Li, Formation of spheroidal microstructure in semi-solid state and thixoforming of 7075 high strength aluminum alloy, Rare Met. 34 (2015) 710–716. https://dx.doi.org/10.1007/s12598-013-0123-0
[35] Y. Hu, S.Q. Fu, L.Z. Zhao, D.H. Wang, F. Liu, Microstructure evolution of semi-solid Mg2Si/A356 composites during remelting process, China Foundry 17 (2020) 384-388. https://dx.doi.org/10.1007/s41230-020-9158-7
[36] M. Kiuchi, R. Kopp, Mushy/Semi-Solid Metal Forming Technology – Present and Future, CIRP Ann. Manuf. Technol. 51 (2002) 653-670. https://doi.org/10.1016/S0007-8506(07)61705-3
[37] J.S. Roh, M. Heo, C.K. Jin, J.H. Park, C.G. Kang, Effect of Current Input Method on A356 Microstructure in Electromagnetically Stirred Process, Metals 10 (2020) 460. https://doi.org/10.3390/met10040460
[38] A. Kolandooz, S.A. Dehlzordi, Effects of important parameters in the production of Al-A356 alloy by semi-solid forming process, J. Mater. Res. Technol. 8 (2018) 189-198. https://dx.doi.org/10.1016/j.jmrt.2017.11.005
[39] W. Khalifa, S. El-Hadad, Y. Tsunekawa, Microstructure characteristics and tensile property of ultrasonic treated-thixocast A356 alloy, Trans. Nonferrous Met. Soc. China 25 (2015) 3173-3180. https://dx.doi.org/10.1016/S1003-6326(15)63949-8
[40] A. Dodangeh, M. Kazeminezhad, H. Aashuri, Effects of cold severe plastic deformation and heating on dendritic and non-dendritic structures: A356 alloy, Int. J. Cast Met. Res. 27 (2014) 312-320. https://dx.doi.org/10.1179/1743133614Y.0000000116
[41] M. Moradi, M. Nili-Ahmadabadi, B. Poorganji, B. Heidarian, T. Furuhara, EBSD and DTA Characterization of A356 Alloy Deformed by ECAP During Reheating and Partial Re-melting, Metall. Mater. Trans. A 45 (2014) 1540-1551. https://dx.doi.org/10.1007/s11661-013-2093-0