Rheological Behaviour of Secondary AlSi7Mg Alloy for Semi-Solid Processing

Abstract:

Semisolid castings are usually produced using primary Al alloys to ensure significant mechanical performances. However, the need to increase the use of secondary alloys is becoming more and more urgent to reduce the carbon footprint of the manufacturing process. In fact, it is well known that the production of primary alloys is far more demanding in terms of energy and emissions than the recycling route. To extend the use of secondary alloys to semisolid processing, it is necessary to thoroughly understand their properties and how they can influence a material with peculiar properties as the semisolid one. Besides microstructural and mechanical features, the rheological behaviour also plays a major role when dealing with processing metals in the semisolid state. Therefore, in the present study, a rheological characterization of secondary AlSi7Mg commercial alloy was carried out and compared to that of the conventional primary alloy. In details, a different content of Fe, Cu and Mn was considered, as these impurities easily form primary intermetallic particles, which can remain dispersed in the liquid matrix of the semisolid metal. The aim of this work is to understand if this can affect the rheological properties of the considered semisolid alloy. Flow curves and yield stresses were obtained from the experimental results to compare the behaviour of the different alloys.

• Periodical: Solid State Phenomena (Volume 347)
• Pages: 107-113
• DOI: https://doi.org/10.4028/p-9IYde2
• Online since: August 2023
• Authors: Marialaura Tocci*, Annalisa Pola, Michael Modigell
• Keywords: Rheology, Secondary Aluminium, Semisolid Processing

References

[1] S.K. Padamata, A. Yasinskiy, P. Polyakov, A Review of Secondary Aluminum Production and Its Byproducts, JOM 73(9) (2021) 2603-2614.

DOI: 10.1007/s11837-021-04802-y

[2] D. Raabe, D. Ponge, P.J. Uggowitzer, M. Roscher, M. Paolantonio, C. Liu, H. Antrekowitsch, E. Kozeschnik, D. Seidmann, B. Gault, F. De Geuser, A. Deschamps, C. Hutchinson, C. Liu, Z. Li, P. Prangnell, J. Robson, P. Shanthraj, S. Vakili, C. Sinclair, L. Bourgeois, S. Pogatscher, Making sustainable aluminum by recycling scrap: The science of "dirty" alloys, Progress in Materials Science 128 (2022) 100947.

DOI: 10.1016/j.pmatsci.2022.100947

[3] S.G. Shabestari, E. Parshizfard, Effect of semi-solid forming on the microstructure and mechanical properties of the iron containing Al–Si alloys, Journal of Alloys and Compounds 509(30) (2011) 7973-7978.

DOI: 10.1016/j.jallcom.2011.05.052

[4] Y. Liu, M. Gao, S. Meng, Y. Fu, W. Li, C. Li, R. Guan, Solidification behavior and enhanced properties of semi-solid Al–8Si–0.5Fe alloys fabricated by rheo-diecasting, Journal of Materials Research and Technology 19 (2022) 3160-3171.

DOI: 10.1016/j.jmrt.2022.06.062

[5] M. Qi, Y. Kang, Y. Xu, Z. Wulabieke, J. Li, A novel rheological high pressure die-casting process for preparing large thin-walled Al–Si–Fe–Mg–Sr alloy with high heat conductivity, high plasticity and medium strength, Materials Science and Engineering: A 776 (2020) 139040.

DOI: 10.1016/j.msea.2020.139040

[6] K.S. Alhawari, M.Z. Omar, M.J. Ghazali, M.S. Salleh, M.N. Mohammed, Microstructural evolution during semisolid processing of Al–Si–Cu alloy with different Mg contents, Transactions of Nonferrous Metals Society of China 27(7) (2017) 1483-1497.

DOI: 10.1016/s1003-6326(17)60169-9

[7] H. MÖLler, W.E. Stumpf, P.C. Pistorius, Influence of elevated Fe, Ni and Cr levels on tensile properties of SSM-HPDC Al-Si-Mg alloy F357, Transactions of Nonferrous Metals Society of China 20 (2010) s842-s846.

DOI: 10.1016/s1003-6326(10)60592-4

[8] D. Kim, J. Kim, J.-Y. Jeon, Y.-W. Kim, E. Kobayashi, Local elongation of a high Fe-containing Al-Si-Cu-Mg alloy by a deformation-semisolid extrusion process, Materials Letters 309 (2022) 131337.

DOI: 10.1016/j.matlet.2021.131337

[9] M. Modigell, A. Pola, Modeling of shear induced coarsening effects in semi-solid alloys, Transactions of Nonferrous Metals Society of China 20(9) (2010) 1696-1701.

DOI: 10.1016/s1003-6326(09)60360-5