Characteristics and Formation Mechanism of the Interface of Mg/Al Bimetallic Composites Prepared by Lost Foam Casting

Abstract:

In the present work, the Mg/Al bimetallic composites were successfully prepared by the lost foam casting (LFC) process, and the characteristics and formation mechanism of the interface of the Mg/Al bimetallic composites were investigated. The results show that a uniform and compact metallurgical interface with an average thickness of about 1400 μm was formed between magnesium alloy and aluminum alloy. The interface layer of the Mg/Al bimetallic composites was composed of three different reaction layers, namely the Al₁₂Mg₁₇+δ(Mg) eutectic layer adjacent to the magnesium matrix, the Al₁₂Mg₁₇+Mg₂Si interlayer and the Al₃Mg₂+Mg₂Si layer close to the aluminum matrix. The microhardnesses of the interface layer were remarkably higher than those of the magnesium and aluminum matrixes. The stress strength of the Mg/Al bimetallic composites was up to 47.67 MPa. The fractograph of the push out sample mainly showed a brittle fracture nature. The formation of the interface of the Mg/Al bimetallic composites was attributed to the fusion and diffusion bonding. With the variations of the concentrations of the different elements at the interface, the Al₃Mg₂ intermetallic phase first formed near to the aluminum matrix, and then the Al₁₂Mg₁₇ and Mg₂Si successively generated toward the magnesium matrix, finally obtaining the interface layer of the Mg/Al bimetallic composites.

• Periodical: Materials Science Forum (Volume 941)
• Pages: 2054-2059
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.941.2054
• Online since: December 2018
• Authors: Wen Ming Jiang*, Zi Tian Fan, Guang Yu Li
• Keywords: Aluminium Alloy, Bimetallic Composites, Formation Mechanism, Interface Characteristic, Lost Foam Casting, Magnesium Alloy

References

[1] W.J. Joost, P.E. Krajewski, Towards magnesium alloys for high-volume automotive applications, Scr. Mater. 128 (2017) 107–112.

DOI: 10.1016/j.scriptamat.2016.07.035

[2] J. Shin, T. Kim, D.E. Kim, D. Kim, K. Kim, Castability and mechanical properties of new 7xxx aluminum alloys for automotive chassis/body applications, J. Alloys Compd. 698 (2017) 577–590.

DOI: 10.1016/j.jallcom.2016.12.269

[3] W.M. Jiang, X, Chen, B.J. Wang, Z.T. Fan, H.B. Wu, Effects of vibration frequency on microstructure, mechanical properties, and fracture behavior of A356 aluminum alloy obtained by expendable pattern shell casting, Int. J. Adv. Manuf. Technol. 83 (2016) 167-175.

DOI: 10.1007/s00170-015-7586-0

[4] J. Hirsch, T. Al-Samman, Superior light metals by texture engineering: Optimized aluminum and magnesium alloys for automotive applications, Acta Mater. 61 (2013) 818–843.

DOI: 10.1016/j.actamat.2012.10.044

[5] T.M. Wang, C.H. Liang, Z.N. Chen, Y.P. Zheng, H.J. Kang, W. Wang, Development of an 8090/3003 bimetal slab using a modified, J. Mater. Process. Technol. 214 (2014) 1806-1811.

DOI: 10.1016/j.jmatprotec.2014.03.029

[6] B. Feng, Y. Xin, F. Guo, H. Yu, Y. Wu, Q. Liu, Compressive mechanical behavior of Al/Mg composite rods with different types of Al sleeve, Acta Mater. 120 (2016) 379–390.

DOI: 10.1016/j.actamat.2016.08.079

[7] J.S. Kim, K.S. Lee, Y.N. Kwon, B.J. Lee, Y.W. Chang, S. Lee, Improvement of interfacial bonding strength in roll-bonded Mg/Al clad sheets through annealing and secondary rolling process, Mater. Sci. Eng. A. 628 (2015) 1–10.

DOI: 10.1016/j.msea.2015.01.035

[8] M. Windmann, A. Röttger, H. Kügler, W. Theisen, Microstructure and mechanical properties of the heat-affected zone in laser-welded/brazed steel 22MnB5–AA6016 aluminum/AZ31 magnesium alloy, J. Mater. Process. Technol. 247 (2017) 11–18.

DOI: 10.1016/j.jmatprotec.2017.04.008

[9] Y. Gao, Y. Morisada, H. Fujii, J. Liao, Dissimilar friction stir lap welding of magnesium to aluminum using plasma electrolytic oxidation interlayer, Mater. Sci. Eng. A. 711 (2018) 109–118.

DOI: 10.1016/j.msea.2017.11.034

[10] G. Xu, A.A. Luo, Y. Chen, A.K. Sachdev, Interfacial phenomena in magnesium/aluminum bi-metallic castings, Mater. Sci. Eng. A. 595 (2014) 154–158.

DOI: 10.1016/j.msea.2013.11.093

[11] E. Hajjari, M. Divandari, S.H. Razavi, T. Homma, S. Kamado, Microstructure characteristics and mechanical properties of Al 413/Mg joint in compound casting process, Metall. Mater. Trans. A 43 (2012) 4667–4677.

DOI: 10.1007/s11661-012-1296-0

[12] W. Jiang, G. Li, Z. Fan, L. Wang, F. Liu, Investigation on the interface characteristics of Al/Mg bimetallic castings processed by lost foam casting, Metall. Mater. Trans. A 47 (2016) 2462–2470.

DOI: 10.1007/s11661-016-3395-9

[13] W.D. Griffiths, M.J. Ainsworth, Instability of the liquid metal-pattern interface in the lost foam casting of aluminum alloys, Metall. Mater. Trans. A 47 (2016) 3137-3149.

DOI: 10.1007/s11661-016-3461-3

[14] W.M. Jiang, Z.T. Fan, D.J. Liu, D.F. Liao, Z. Zhao, X.P. Dong, H.B. Wu, Influence of process parameters on filling ability of A356 aluminium alloy in expendable pattern shell casting with vacuum and low pressure, Int. J. Cast Metal. Res. 25 (2012) 47-52.

DOI: 10.1179/1743133611y.0000000014

[15] W. Jiang, Z. Fan, G. Li, L. Yang, X. Liu, Effects of melt-to-solid insert volume ratio on the microstructures and mechanical properties of Al/Mg bimetallic castings produced by lost foam casting, Metall. Mater. Trans. A 47 (2016) 6487–6497.

DOI: 10.1007/s11661-016-3788-9

[16] S.M. Emami, M. Divandari, E. Hajjari, H. Arabi, Comparison between conventional and lost foam compound casting of Al/Mg light metals, Int. J. Cast Metal. Res. 26 (2013) 43-50.

DOI: 10.1179/1743133612y.0000000037

[17] K.A. Guler, A. Kisasoz, A. Karaaslan, Fabrication of Al/Mg bimetal compound casting by lost foam technique and liquid-solid process, Mater. Test. 56 (2014) 700-702.

DOI: 10.3139/120.110624