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The influence of heat treatment on the structure and tensile properties of thin-section A356 aluminum alloy casts refined by Ti, B and Zr

Published online by Cambridge University Press:  29 May 2017

Masoud Emamy
Affiliation:
School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran 1417614418, Iran
Mehdi Malekan*
Affiliation:
School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran 1417614418, Iran
Amir Hosein Pourmonshi
Affiliation:
Department of Materials Engineering, Islamic Azad University, South Tehran Branch, Tehran 1777613651, Iran
Kourosh Tavighi
Affiliation:
School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran 1417614418, Iran
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

The aim of this study is to investigate the effects of different master alloys containing Ti, B, and Zr on the structure and tensile properties of thin-section A356 aluminum alloy in as-cast and T6-treated conditions. Microstructural examinations were performed using light optical and scanning electron microscopy. The results showed that the addition of 0.1 wt% Ti, 0.05 wt% B, and 0.1 wt% Zr decreases the average grain size of the cast alloy from 840 μm to 387 μm, 236 μm, and 363 μm, respectively. This structural refinement results in the variation of the α-Al primary phase distribution mode from dendritic to rosettelike. It has been found that 0.6 wt% Al–8B master alloy (0.05 wt% B) is the strongest to refine the structural parameters. This leads to the enhancement of both ultimate tensile strength and elongation values from 208 MPa and 6.2% in as-cast to 290 MPa and 12.5% in B-refined alloy at T6-treated conditions. In addition, the presence of more fine dimples on the fracture surfaces of the T6-treated specimens revealed that T6-treatment encourages ductile mode of fracture.

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Articles
Copyright
Copyright © Materials Research Society 2017 

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Footnotes

Contributing Editor: Jürgen Eckert

References

REFERENCES

Liu, L. and Samuel, F.H.: Effect of inclusions on the tensile properties of Al–7% Si–0.35% Mg (A356.2) aluminium casting alloy. J. Mater. Sci. 33, 2269 (1998).CrossRefGoogle Scholar
Conley, J.G., Huang, J., Asada, J., and Akiba, K.: Modeling the effects of cooling rate, hydrogen content, grain refiner and modifier on microporosity formation in Al A356 alloys. Mater. Sci. Eng., A 285, 49 (2000).CrossRefGoogle Scholar
Dahle, A.K., Nogita, K., McDonald, S.D., Dinnis, C., and Lu, L.: Eutectic modification and microstructure development in Al–Si Alloys. Mater. Sci. Eng., A 413–414, 243 (2005).Google Scholar
Khan, K.B., Kutty, T.R.G., and Surappa, M.K.: Hot hardness and indentation creep study on Al–5% Mg alloy matrix–B4C particle reinforced composites. Mater. Sci. Eng., A 427, 76 (2006).Google Scholar
Murty, B.S., Kori, S.A., and Chakraborty, M.: Grain refinement of aluminium and its alloys by heterogeneous nucleation and alloying. Int. Mater. Rev. 47, 3 (2002).Google Scholar
Dahle, A.K.: Nucleation and grain refinement. Mater. Sci. Forum 649, 287 (2010).Google Scholar
StJohn, D.H., Qian, M., Easton, M.A., and Cao, P.: The interdependence theory: The relationship between grain formation and nucleant selection. Acta Mater. 59, 4907 (2011).Google Scholar
Birol, Y.: Effect of the salt addition practice on the grain refining efficiency of Al–Ti–B master alloys. J. Alloys Compd. 420, 207 (2006).Google Scholar
Faraji, M., Wright, J.P., and Katgerman, L.: In situ observation of the nucleation kinetics and the mechanism of grain refinement in Al–Si alloys (Part I). Mater. Lett. 64, 1016 (2010).Google Scholar
Cibula, A.: The mechanism of grain refinement of sand castings in aluminium alloys. J. Inst. Met. 76, 321 (1949).Google Scholar
Pacz, A.: Alloy. U.S. Patent No. 1387900, 1921.Google Scholar
Fan, Z., Wang, Y., Zhang, Y., Qin, T., Zhou, X.R., Thompson, G.E., Pennycook, T., and Hashimoto, T.: Grain refining mechanism in the Al/Al–Ti–B system. Acta Mater. 84, 292 (2015).Google Scholar
Cibula, A.: The grain refinement of aluminum alloy castings by additions of titanium and boron. J. Inst. Met. 80, 1 (1951–1952).Google Scholar
Mohanty, P.S. and Gruzleski, J.E.: Mechanism of grain refinement in aluminium. Acta Mater. 43, 2001 (1995).Google Scholar
Liu, Y., Ding, C., and Li, Y.X.: Grain refining mechanism of Al–3B master alloy on hypoeutectic Al–Si alloys. Trans. Nonferrous Met. Soc. China 21, 1435 (2011).Google Scholar
Birol, Y.: AlB3 master alloy to grain refine AlSi10Mg and AlSi12Cu aluminium foundry alloys. J. Alloys Compd. 513, 150 (2012).Google Scholar
Seyed Ebrahimi, S.H. and Emamy, M.: Effects of Al–5Ti–1B and Al–5Zr master alloys on the structure, hardness and tensile properties of a highly alloyed aluminum alloy. Mater. Des. 31, 200 (2010).CrossRefGoogle Scholar
Baradarani, B. and Raiszadeh, R.: Precipitation hardening of cast Zr-containing A356 aluminium alloy. Mater. Des. 32, 935 (2011).Google Scholar
Mahmudi, R., Sepehrband, P., and Ghasemi, H.M.: Improved properties of A319 aluminum casting alloy modified with Zr. Mater. Lett. 60, 2606 (2006).Google Scholar
Sepehrband, P., Mahmudi, R., and Khomamizadeh, F.: Effect of Zr addition on the aging behavior of A319 aluminum cast alloy. Scr. Mater. 52, 253 (2005).Google Scholar
Ji-hua, P., Xiao-long, T., Jian-ting, H., and De-ying, X.: Effect of heat treatment on microstructure and tensile properties of A356 alloys. Trans. Nonferrous Met. Soc. China 21, 1950 (2011).Google Scholar
Abdulwahab, M., Madugu, I.A., Yaro, S.A., Hassan, S.B., and Popoola, A.P.I.: Effects of multiple-step thermal ageing treatment on the hardness characteristics of A356.0-type Al–Si–Mg alloy. Mater. Des. 32, 1159 (2011).Google Scholar
Zhu, M., Jian, Z., Yang, G., and Zhou, Y.: Effects of T6 heat treatment on the microstructure, tensile properties, and fracture behavior of the modified A356 alloys. Mater. Des. 36, 243 (2012).Google Scholar
Shabestari, S.G. and Shahri, F.: Influence of modification, solidification conditions and heat treatment on the microstructure and mechanical properties of A356 aluminum alloy. J. Mater. Sci. 39, 2023 (2004).Google Scholar
Emamy, M., Nemati, N., and Heidarzadeh, A.: The influence of Cu rich intermetallic phases on the microstructure, hardness and tensile properties of Al–15% Mg2Si composite. Mater. Sci. Eng., A 527, 2998 (2010).Google Scholar
ASM International: Metals Handbook, Properties and Selection: Nonferrous Alloys and Special Purpose Materials, 10th ed. (ASM International, Materials Park, 1990).Google Scholar
Quested, T.E. and Greer, A.L.: The effect of the size distribution of inoculant particles on as-cast grain size in aluminium alloys. Acta Mater. 52, 3859 (2004).CrossRefGoogle Scholar
Rokhlin, L.L., Dobatkina, T.V., Bochvar, N.R., and Lysova, E.V.: Investigation of phase equilibria in alloys of the Al–Zn–Mg–Cu–Zr–Sc system. J. Alloys Compd. 367, 10 (2004).Google Scholar
Jones, G.P. and Pearson, J.: Factors affecting the grain-refinement of aluminum using titanium and boron additives. Metall. Trans. B 7, 223 (1976).CrossRefGoogle Scholar
Senkov, O.N., Bhat, R.B., Senkova, S.V., and Schloz, J.D.: Microstructure and properties of cast ingots of Al–Zn–Mg–Cu alloys modified with Sc and Zr. Metall. Mater. Trans. A 36, 2115 (2005).Google Scholar
Nadella, R., Eskin, D.G., Du, Q., and Katgerman, L.: Macrosegregation in direct-chill casting of aluminium alloys. Prog. Mater. Sci. 53, 421 (2008).Google Scholar
Birol, Y.: Effect of silicon content in grain refining hypoeutectic Al–Si foundry alloys with boron and titanium additions. Mater. Sci. Technol. 28, 385 (2012).CrossRefGoogle Scholar
Quested, T.E., Dinsdale, A.T., and Greer, A.L.: Thermodynamic modelling of growth-restriction effects in aluminium alloys. Acta Mater. 53, 1323 (2005).Google Scholar
Malekan, A., Emamy, M., Rassizadehghani, J., and Emami, A.R.: The effect of solution temperature on the microstructure and tensile properties of Al–15% Mg2Si composite. Mater. Des. 32, 2701 (2011).Google Scholar
Wang, E.R., Hui, X.D., Wang, S.S., Zhao, Y.F., and Chen, G.L.: Improved mechanical properties in cast Al–Si alloys by combined alloying of Fe and Cu. Mater. Sci. Eng., A 527, 7878 (2010).Google Scholar
ASM International: Metals Handbook: Fractography, 2nd ed., Vol. 12 (ASM international, Materials Park, 1998).Google Scholar