Influence of Sr Addition on the Microstructure and Properties of HPDC EN AC-Al Si9Cu3(Fe) Alloy

Abstract:

The following paper presents results of the researches on the influence of Sr addition on microstructure and mechanical properties of EN AC-Al Si9Cu3(Fe) HPDC alloy. Two different elements were high pressure die cast for the research, one with Sr addition, second one without. Investigations involved light and scanning electron microscopy as well as hardness and tensile testing. EN AC-Al Si9Cu3(Fe) HPDC alloy microstructure is characterized by a fine dendrites of α-Al solid solution and AlSi binary eutectic mixture. What is more, many intermetallic phases are observed in the alloy. These are: α-Al₁₅(Fe,Mn,Cr)₃Si₂, β-A₅FeSi, A₂Cu, π-A₈Mg₃FeSi₆ and Q-A_l5Mg₈Cu₂Si₆. Sr modified alloy is characterized by a significant volume fraction of fine, fibrous AlSi-eutectic. The porosity in the modified alloy slightly decreased. Mechanical properties of the alloy increased after Sr modification.

• Periodical: Key Engineering Materials (Volume 682)
• Pages: 69-76
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.682.69
• Online since: February 2016
• Authors: Łukasz Poloczek*, Bartłomiej Dybowski, Andrzej Kiełbus, Michał Łuszczak
• Keywords: AlSi9Cu(Fe) Alloy, High Pressure Die Casting, Microstructure, Modification, Tensile Properties

References

[1] JR. Davis, ASM handbook. ASM, Metals Park, OH. (1990) 123–151, 166–168.

[2] J. Cais, V. Weiss, J. Svobodova , Relation between Porosity and Mechanical Properties of Al-Si Alloys Produced by Low- Pressure Casting, Archives of Foundry Engineering, V14 - SI1 20. (2014).

[3] M. Conserva, F. Bonollo, G. Donzelli, Alluminio, manuale degli impieghi, Edimet, Brescia, Italy, (2004).

[4] M.A. Alam Najafabadi, A. Ourdjini, R. Elliot, Impurity modification of aluminum silicon eutectic alloys. Cast Metals, vol. 8, No 1, 43-50.

DOI: 10.1080/09534962.1995.11819192

[5] M.A. Alam Najafabadi, S. Khant, A. Ourdjini, R. Elliot, The flake-fibre transition in aluminum-silicon eutectic alloys. Cast Metals, vol. 8, No 1, 35-42.

DOI: 10.1080/09534962.1995.11819191

[6] L. Liu, A.M. Samuel, F. H Samuel, Role of strontium oxide on porosity formation in Al-Si casting alloys. AFS Transactions vol. 139. (2002), 1-14.

[7] R. Fuoco, E. R Correa, H. Goldenstein, Effect of modification treatment on microporosity formation in A356 alloy. Part I: Interdendritic feeding evaluation. AFS Transactions, vol. 9104. (1996), 1151-1157.

[8] F. Sanna, A. Fabrizi, S. Ferraro, G. Timelli, P. Ferro, F. Bonollo, Multiscale characterisation of AlSi9Cu3(Fe) die casting alloys after Cu, Mg, Zn and Sr addition, La Metallurgia Italiana 4. (2013) 13-24.

DOI: 10.1016/j.matchar.2013.08.012

[9] S.G. Shabestari, The effect of iron and manganese on the formation of intermetallic compounds in aluminum–silicon alloys, Materials Science and Engineering A 383. (2004) 289–298.

DOI: 10.1016/s0921-5093(04)00832-9

[10] G. Timelli, F. Bonollo, The influence of Cr content on the microstructure and mechanical properties of AlSi9Cu3(Fe) die-casting alloys Materials Science and Engineering A 528. (2010) 273–282.

DOI: 10.1016/j.msea.2010.08.079

[11] . S. Ferraro, A. Fabrizi, G. Timelli, Evolution of sludge particles in secondary die-cast aluminum alloys as function of Fe, Mn and Cr contents, Materials Chemistry and Physics 153. (2015) 168-179.

DOI: 10.1016/j.matchemphys.2014.12.050

[12] A. Fabrizi, S. Ferraro, G. Timelli, The influence of Sr, Mg and Cu addition on the microstructural properties of a secondary AlSi9Cu3(Fe) die casting alloy, Materials Characterization 85. (2013) 13-25.

DOI: 10.1016/j.matchar.2013.08.012

[13] J. Shouxun, W. Douglas, W. Yun, M. White, Z. Fan, Effect of Ti Addition on Mechanical Properties of High Pressure Die Cast Al-Mg-Si Alloys, Materials Science Forum 765. (2013) 23-27.

DOI: 10.4028/www.scientific.net/msf.765.23

[14] L. Wang, S. Shivkumar, Strontium modification of aluminium alloy castings in the expendable pattern casting process, Journal of Materials Science 30 (1995).

DOI: 10.1007/bf00375269

[15] R. Gautam Krishnan, E. M. Somasekharan Nair, Study of strontium modification in aluminium alloy, International Journal of Emerging Technology and Advanced Engineering Volume 3, Issue 10. (2013) 753-760.