Microstructure and Bonding Strength of AZ91/Al Composite Fabricated by Brazing and Hot-Rolling

Abstract:

In order to achieve the composite of the AZ91 magnesium alloy and pure aluminum sheet, Zn-Sn-Al solder as compound agent, electric arc plating was employed to spray the brazing solder on the surface of AZ91 and pure Al sheets. The sheets were then subjected to heat treatment at 420 for 10min before rolling lamination at a reduction of 10%. The as-rolled sheets were annealed at 390 for 4hours. The microstructure, phase constitution and bonding strength of the composite interface were tested and analyzed by using SEM and energy dispersive scope (EDS), x-ray diffraction and tensile test. Experimental results showed that, under the atmospheric environment, AZ91/Al composite can be successfully fabricated with Zn-Sn-Al solder by brazing and hot-rolling, and the shearing strength can reach 22.46MPa. After annealing for 4 hours, a diffusion layer composed mainly of Al and Zn elements was formed near Al matrix, and the intermetallic phases were MgZn₂ and Mg₂Sn which was the same to the phases at the interface of AZ91/Al composite without annealing, but the amount was relatively higher. The interfacial fracture of composite was mainly due to the existence of intermetallic phases.

• Periodical: Materials Science Forum (Volumes 747-748)
• Pages: 264-269
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.747-748.264
• Online since: February 2013
• Authors: Lin Yang, De Wen Zhao, Zhong Li Zhang, Hong Liang Shan, Lin Yang, Zheng Liu
• Keywords: Bonding Strength, Brazing, Composite, Hot-Rolling, Magnesium Alloy

References

[1] X. Cao, M. Jahazi, Effect of welding speed on the quality of friction stir welded butt joints of a magnesium alloy, J. Mater Design. 30 (2009) 2033-(2042).

DOI: 10.1016/j.matdes.2008.08.040

[2] G. Padmanaban, V. Balasubramanian, Selection of FSW tool pin profile, shoulder diameter and material for joining AZ31B magnesium alloy–an experimental approach, J. Mater Design. 30 (2009) 2647-(2056).

DOI: 10.1016/j.matdes.2008.10.021

[3] L. Ma, D.Y. He, X.Y. Li, et al., Microstructure and mechanical properties of magnesium alloy AZ31B brazed joint using a Zn–Mg–Al filler metal, J. Mater Sci Technol. 26 (2010) 743-746.

DOI: 10.1016/s1005-0302(10)60117-x

[4] Z.L. Zhang, Y. Ding, X. Wang, et al., Improvement of surface corrosion resistance for magnesium alloy by combining thermal spray and cast-infiltration, J. Trans Nonferrous Met Soc China. 20 (2010) 992-996.

DOI: 10.1016/s1003-6326(09)60247-8

[5] X.H. Du, E.L. Zhang, Microstructure and mechanical behaviour of semi-solid die-casting AZ91D magnesium alloy, J. Mater Lett. 61 (2007) 2333-2337.

DOI: 10.1016/j.matlet.2006.09.007

[6] L.M. Liu, X.D. Qi, Z.H. Wu, Microstructural characteristics of lap joint between magnesium alloy and mild steel with and without the addition of Sn elemen, J t. Mater Lett. 64 (2011) 89-92.

DOI: 10.1016/j.matlet.2009.10.023

[7] B.Y. Huang, Situation anf development strategy of China non-ferrous materials, J. Chinese Journal of Nonferrous metals. 14 (2004) 122-127.

[8] L.M. Liu, J.H. Tan, X.J. Liu, Reactive brazing of Al alloy to Mg alloy using zine-based brazing alloy, J. Materials Letters. 61 (2007) 2373-2377.

DOI: 10.1016/j.matlet.2006.09.016

[9] H. Wang, L.M. Liu, X.J. Liu, Mg-Al dissimilar materials TIG welded joints diffusion behavior, J. Welding Technology. 26 (2005) 5-8.