Tensile properties and hot tearing susceptibility of cast Al-Cu alloys containing excess Fe and Si

Abstract

This study was undertaken to investigate the tensile properties and hot tearing susceptibility of cast Al-Cu alloys containing excess Fe (up to 1.5wt%) and Si (up to 2.5wt%). According to the results, the optimum tensile properties and hot tearing resistance were achieved at Fe/Si mass ratio of 1, where the α-Fe phase was the dominant Fe compound. Increasing the Fe/Si mass ratio above unity increased the amounts of detrimental β-CuFe platelets in the microstructure, deteriorating the tensile properties and hot tearing resistance. Decreasing the mass ratio below unity increased the size and fraction of Si needles and micropores in the microstructure, also impairing the tensile properties and hot tearing resistance. The investigation of hot-torn surfaces revealed that the β-CuFe platelets disrupted the tear healing phenomenon by blocking interdendritic feeding channels, while the a-Fe intermetallics improved the hot tearing resistivity due to their compact morphology and high melting point.

Keywords

aluminum-copper alloys / castability / fluidity / hot tearing susceptibility

References

[1] Lemieux A, Langlais J, Bouchard D, Chen XG. Effect of Si, Cu and Fe on mechanical properties of cast semi-solid 206 alloys. Trans. Nonferrous Met. Soc. China, 2010, 20(9): 1555.

[2] Tiryakioğlu M, Campbell J, Alexopoulos ND. On the ductility potential of cast Al-Cu-Mg (206) alloys. Mater. Sci. Eng. A, 2009, 506(1–2): 23.

[3] Sheykh-jaberi F, Cockcroft SL, Maijer DM, Phillion AB. Comparison of the semi-solid constitutive behaviour of A356 and B206 aluminum foundry alloys. J. Mater. Process. Technol., 2019, 266, 37.

[4] Elgallad EM, Chen XG. On the microstructure and solution treatment of hot tearing resistant semi-solid 206 alloy. Mater. Sci. Eng. A, 2012, 556, 783.

[5] Esfahani MRN, Niroumand B. Study of hot tearing of A206 aluminum alloy using instrumented constrained T-shaped casting method. Mater. Charact., 2010, 61(3): 318.

[6] Zhao YL, Zhang WW, Yang C, Zhang DT, Wang Z. Effect of Si on Fe-rich intermetallic formation and mechanical properties of heat-treated Al-Cu-Mn-Fe alloys. J. Mater. Res., 2018, 33(8): 898.

[7] Belov NA, Aksenov AA, Eskin DG. Iron in Aluminnium Alloys: Impurity and Alloying Elements, 2002, New York, CRC Press

[8] Liu K, Cao X, Chen XG. Solidification of iron-rich inter-metallic phases in AF-4.5Cu-0.3Fe cast alloy. Metall. Mater. Trans. A, 2011, 42(7): 2004.

[9] Kamga HK, Larouche D, Bournane M, Rahem A. Mechanical properties of aluminium-copper B206 alloys with iron and silicon additions. Int. J. Cast Met. Res., 2012, 25(1): 15.

[10] Zhang WW, Zhao YL, Zhang DT, Luo ZQ, Yang C, Li YY. Effect of Si addition and applied pressure on microstructure and tensile properties of as-cast Al-5.0Cu-0.6Mn-1.2Fe alloys. Trans. Nonferrous Met. Soc. China, 2018, 28(6): 1061.

[11] Liu K, Cao X, Chen XG. Effect of Mn, Si, and cooling rate on the formation of iron-rich intermetallics in 206 Al-Cu cast alloys. Metall. Mater. Trans. B, 2012, 43(5): 1231.

[12] Liu K, Cao X, Chen XG. Tensile properties of Al-Cu 206 cast alloys with various iron contents. Metall. Mater. Trans. A, 2014, 45(5): 2498.

[13] Taghaddos E, Hejazi MM, Taghiabadi R, Shabestari SG. Effect of iron-intermetallics on the fluidity of 413 aluminum alloy. J. Alloys Compd., 2009, 468(1–2): 539.

[14] Mbuya TO, Odera BO, Ng’ang’a SP. Influence of iron on castability and properties of aluminium silicon alloys: Literature review. Int. J. Cast Met. Res., 2003, 16(5): 451.

[15] Kamga HK, Larouche D, Bournane M, Rahem A. Hot tearing of aluminum-copper B206 alloys with iron and silicon additions. Mater. Sci. Eng. A, 2010, 527(27–28): 7413.

[16] Bolouri A, Liu K, Chen XG. Effects of iron-rich inter-metallics and grain structure on semisolid tensile properties of Al-Cu 206 cast alloys near solidus temperature. Metall. Mater. Trans. A, 2016, 47(12): 6466.

[17] D’Elia F, Ravindran C, Sediako D, Kainer KU, Hort N. Hot tearing mechanisms of B206 aluminum-copper alloy. Mater. Des., 2014, 64, 44.

[18] Bishop HF, Ackerlind CG, Pellini WS. Metallurgy and mechanics of hot tearing. AFS Trans., 1952, 60, 818.

[19] Liu K, Cao X, Bolouri A, Chen X-G. Tiryakioğlu M, Griffiths W, Jolly M. Effect of Fe-rich intermetallics on tensile behavior of Al-Cu 206 cast alloys at solid and near-solid states. Shape Casting, 2019, Cham, Springer, 85.

[20] Han N, Bian XF, Li ZK, Mao T, Wang CD. Effect of Si on the microstructure and mechanical properties of the Al-4.5%Cu alloys. Acta Metall. Sinica, 2006, 19(6): 405.

[21] Kaufman JG. Introduction to Aluminum Alloys and Tempers, 2000, Materials Park, OH, ASM International, 15.

[22] Lin S. A Study of Hot Tearing in Wrought Aluminum Alloys, 1999, Chicoutimi, PQ, University of Québec in Chicoutimi Dissertation]

[23] Lin S, Aliravci C, Pekguleryuz MO. Hot-tear susceptibility of aluminum wrought alloys and the effect of grain refining. Metall. Mater. Trans. A, 2007, 38(5): 1056.

[24] Taghiabadi R, Fayegh A, Pakbin A, Nazari M, Ghoncheh MH. Quality index and hot tearing susceptibility of Al-7Si-0.35Mg-xCu alloys. Trans. Nonferrous Met. Soc. China, 2018, 28(7): 1275.

[25] Bai SG, Perevoshchikova N, Sha Y, Wu XH. The effects of selective laser melting process parameters on relative density of the AlSi10Mg parts and suitable procedures of the Archimedes method. Appl. Sci., 2019, 9(3): 583.

[26] Tenekedjiev N, Gruzleski JE. Hypereutectic aluminium-silicon casting alloys—A review. Cast Met., 1990, 3(2): 96.

[27] Jamaati R, Amirkhanlou S, Toroghinejad MR, Niroumand B. CAR process: A technique for significant enhancement of as-cast MMC properties. Mater. Charact., 2011, 62(12): 1228.

[28] Qian L, Toda H, Nishido S, Kobayashi T. Experimental and numerical investigations of the effects of the spatial distribution of a phase on fracture behavior in hypoeutectic Al-Si alloys. Acta Mater., 2006, 54(18): 4881.

[29] Gupta M, Ling S. Microstructure and mechanical properties of hypo/hyper-eutectic Al-Si alloys synthesized using a near-net shape forming technique. J. Alloys Compd., 1999, 287(1–2): 284.

[30] Průša F, Bláhová M, Vojtěch D, Kučera V, Bernatiková A, Kubatík TF, Michalcová A. High-strength ultra-finegrained hypereutectic Al-Si-Fe-X (X = Cr, Mn) alloys prepared by short-term mechanical alloying and spark plasma sintering. Materials, 2016, 9(12): 973.

[31] Prach O, Trudonoshyn O, Randelzhofer P, Körner C, Durst K. Effect of Zr, Cr and Sc on the Al-Mg-Si-Mn high-pressure die casting alloys. Mater. Sci. Eng. A, 2019, 759, 603.

[32] Cáceres CH, Djurdjevic MB, Stockwell TJ, Sokolowski JH. The effect of Cu content on the level of microporosity in Al-Si-Cu-Mg casting alloys. Scripta Mater., 1999, 40(5): 631.

[33] Di Sabatino M. On fluidity of aluminium alloys. Metall. Ital., 2008, 100(3): 17.

[34] Magnusson T, Arnberg L. Density and solidification shrinkage of hypoeutectic aluminum-silicon alloys. Metall. Mater. Trans. A, 2001, 32(10): 2605.

[35] Razaz G, Carlberg T. Hot tearing susceptibility of AA3000 aluminum alloy containing Cu, Ti, and Zr. Metall. Mater. Trans. A, 2019, 50(8): 3842.

[36] M. Rappaz, I. Farup, and J.-M. Drezet, Study and modeling of hot tearing formation, [in] Proceedings of the Merton C. Flemings Symposium on Solidification and Materials Processing, Cambridge, Massachusetts, 2000, p. 213.

[37] Flemings MC, Niyama E, Taylor HF. Fluidity of aluminium alloys: An experimental and quantitative evaluation. AFS Trans., 1961, 69, 625.