Inoculation and Fading of Sr-Modified A356.2 Aluminum Alloy in Squeeze Casting

Abstract:

The inoculation and fading behavior of Sr-modified aluminum alloy A356. 2 were studied for air bag bracket produced by squeeze casting. The effects of Sr, P, B contents and casting temperature on the microstructure and eutectic silicon morphology in different periods of inoculation were investigated by SEM and direct-reading Spectrometer. The influence of inoculation fading rate and addition of Sr on the casting mechanical properties and hydrogen absorption was studied. The experimental results showed that the inoculation process was completed in 1 h, and the eutectic silicon morphology can be maintained in almost subsequent 40 h after the addition of Sr. The fading rate decreased appreciably with the increase of casing temperature, P and B contents. The deleterious effect of the inoculation fading of Sr on the casting mechanical property can be compensated by the squeeze casting.

• Periodical: Materials Science Forum (Volume 850)
• Pages: 671-678
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.850.671
• Online since: March 2016
• Authors: Jian Wei Niu, Lie Jun Li, Hai Jun Liu, Ji Xiang Gao, Chuan Dong Ren
• Keywords: A356.2 Aluminum Alloy, Inoculation Fading, Squeeze Casting, Sr-Modifier

References

[1] O. Elsebaie, A. M. Samuel, F. H. Samuel. Effects of Sr-modification, iron-based intermetallics and aging treatment on the impact toughness of 356 Al-Si-Mg alloy. J Mater Sci 46(2011) 3027-3045.

DOI: 10.1007/s10853-010-5181-1

[2] M. Timpel, N. Wanderka, G. S. Vinod Kumar, J. B. Anhart, Microstructural investigation of Sr modified Al-15 wt. %Si alloys in the range from micrometer to atomic scale. Ultramicroscopy 111 (2011) 695-700.

DOI: 10.1016/j.ultramic.2010.12.023

[3] A. K. Prasad Raoa, K. D. as, B.S. Murty, et al. On the modification and segregation behavior of Sb in Al–7Si during solidification[J]. Materials Letters, 62(2008) 2013-(2016).

DOI: 10.1016/j.matlet.2007.11.005

[4] H. C. Liao , G. X. Sun. Mutual poisoning effect between Sr and B in Al-Si casting alloys[J]. Scripta Materialia, 48(2003) 1035-1039.

DOI: 10.1016/s1359-6462(02)00648-6

[5] J. Campbell, L. M. Tiryakio. Review of effect of P and Sr on modification and porosity development in Al-Si alloys[J]. Materials Science and Technology, 26(2010) 262-268.

DOI: 10.1179/174328409x425227

[6] S. G. Shabestari, S.M. Miresmaeili, S.M.A. Boutorabi. Effects of Sr-modification and melt cleanliness on melt hydrogen absorption of 319 aluminium alloy. Journal of materials science. 38 (2003) 1901-(1907).

[7] F. Zupanic, S. Spaic, A. Krizman. Contribution to the ternary system Al-TiB. Part2-Study of alloys in Al-AlB 2 -TiB 2 triangle. Mater Sci Technol . 14(1998)1203.

DOI: 10.1179/mst.1998.14.12.1203

[8] D. G. Mallapur, S. A. Kori, Udupa, K. Rajendra. Influence of Ti, B and Sr on the microstructure and mechanical properties of A356 alloy[J] Mater Sci. 46 (2011) 1622-1627.

DOI: 10.1007/s10853-010-4977-3

[9] H. Li, T. Sritharan, Y.M. Lam. Effects of processing parameters on the performance of Al grain refinement master alloys Al-Ti and Al-B in small ingots. J Mater Process Technol 66(1997) 153-257.

DOI: 10.1016/s0924-0136(96)02536-8

[10] J. H. Kim; J.W. Choi; J.P. Choi. A study on the variation of solidification contraction of A356 aluminum alloy with Sr addition. Journal of materials science letters. 1 9(2000)1395-1398.

[11] S. S. LI, J.L. Tang, D.B. Zeng. Inoculation and Fading of Sr Modification in Hypoeutectic Al-Si Alloys[J]. Foundry. 54(4)(2005)344-347.

[12] A. M. Samuel, H.W. Doty, S. Valtierra, F.H. Samuel. Effect of grain refining and Sr modification interactions on the impact toughness of Al–Si–Mg cast alloys. Materials and Design 56 (2014) 264-273.

DOI: 10.1016/j.matdes.2013.10.029

[13] R. Fuoco, H. Goldenstein. Effect of modification treatment on microporousily formation in A356 Al alloy, part 2: dendrite morphology[J]. AFS Transactions. 91(1997)883-889.

[14] S. Z. Lu, A. Hellawell. The mechanisms of silicon in Al-Si alloys crystal growth. 73(1985)316-328.

DOI: 10.1016/0022-0248(85)90308-2

[15] L. Liu, A. M. Samuel, F. H. Samuel. Characteristics of a-dendritic and eutectic structures in Sr-treated Al-Si casting alloys. Journal of materials science. 39(2004)215-224.

DOI: 10.1023/b:jmsc.0000007747.43275.34

[16] M. Marzouk, M. Jain, S. Shankar. Effect of Sr-modification on the bendability of cast aluminum alloyA356 using digital image correlation method. Materials Science & Engineering. A598 (2014) 277-287.

DOI: 10.1016/j.msea.2014.01.011