Joining of Aluminum and Steel using AlSi12 Brazing Filler in a Protective Atmosphere Furnace: Microstructure and Mechanical Properties
Yijun Man （ Singapore Institute of Manufacturing Technology, 73 Nanyang Drive, Singapore 637662 ）
Dayou Pan （ Singapore Institute of Manufacturing Technology, 73 Nanyang Drive, Singapore 637662 ）
Shibo Liu （ Singapore Institute of Manufacturing Technology, 73 Nanyang Drive, Singapore 637662 ）https://doi.org/10.37155/2717-526X-0302-2
Brazing of pure aluminum (Al) to steel using an Al-12 wt. %Si (AlSi12) filler metal and an Al brazing flux was performed in furnace filled with protective atmosphere. Microstructure characterizations of the full/fractured joints, tensile shear strength and micro-hardness tests were performed on the samples with holding time from 5-30 min at brazing temperature of 600 °C and additional thermal exposure of 30 min at temperature of 480 °C. It is found that the joint seam for all samples features roughly into four layers, among them, the layer adjacent to steel is an IMC layer and dominantly distributed with h phase. The tensile shear strength of joints is inversely proportional to the thickness of h phase layer and particularly governed by a specific zone which is located in the h phase layer, directly adjacent to the interface between h phase layer and steel and scattered with a lot of visible pores and cracks. Micro-hardness tests show the hardness of the h phase layer remains the highest for each holding time and increases with the increase of holding time. The higher hardness leads to the limited plasticity of the η phase and more fragile of this layer. Furthermore, great differences of hardness exist between the η phase layer and steel may also generate great stresses that induce the crack initiation in the specific zone and finally result in the failure of brazed joints.
KeywordsFurnace brazing; Dissimilar material; Pure aluminum; Steel; Al-12 wt. %Si filler metal; Flux; Intermetallic compounds (IMCs); Tensile shear strength; Microstructure; Micro-hardness
.Liu, S.; Suzumura, A.; Ikeshoji, T.-T.; Yamazaki, T. Brazing of Stainless Steel to Various Aluminum Alloys in Air. JSME Int. J., Ser. A 2005, 48 (4), 420–425. https://doi.org/10.1299/jsmea.48.420.
.Winiowski, A. Structural and Mechanical Propertoes of Brazed Joints of Stainless Steel and Aluminum. Archives of metallurgy and materials 2009, 54 (2), 11.
.Springer, H.; Kostka, A.; Payton, E. J.; Raabe, D.; Kaysser-Pyzalla, A.; Eggeler, G. On the Formation and Growth of Intermetallic Phases during Interdiffusion between Low-Carbon Steel and Aluminum Alloys. Acta Materialia 2011, 59 (4), 1586–1600. https://doi.org/10.1016/j.actamat.2010.11.023.
.Springer, H.; Kostka, A.; dos Santos, J. F.; Raabe, D. Influence of Intermetallic Phases and Kirkendall-Porosity on the Mechanical Properties of Joints between Steel and Aluminum Alloys. Materials Science and Engineering: A 2011, 528 (13–14), 4630–4642. https://doi.org/10.1016/j.msea.2011.02.057.
.Fedorov, V.; Weis, S.; Wagner, G. Mechanical and Microstructural Behavior of Brazed Aluminum / Stainless Steel Mixed Joints. IOP Conf. Ser.: Mater. Sci. Eng. 2016, 118, 012003. https://doi.org/10.1088/1757-899X/118/1/012003.
.Fedorov, V.; Elßner, M.; Uhlig, T.; Wagner, G. Interfacial Microstructure and Mechanical Properties of Brazed Aluminum / Stainless Steel - Joints. IOP Conf. Ser.: Mater. Sci. Eng. 2017, 181, 012009. https://doi.org/10.1088/1757-899X/181/1/012009.
.Abood, A.; Mohammed, M. Furnace Brazing of AA5086 Aluminum Alloy with AISI 316L Stainless Steel by ER4047 and ER4043 Fillers. Journal of King Abdulaziz University-Engineering Sciences 2018, 29 (1). https://doi.org/10.4197/Eng.29-1.3.
.Yu, G.; Zou, T.; Chen, S.; Huang, J.; Yang, J.; Zhao, Z. Effect Mechanism of Ni Coating Layer on the Characteristics of Al/Steel Dissimilar Metal Brazing. Materials Characterization 2020, 167, 110518. https://doi.org/10.1016/j.matchar.2020.110518.
.Fedorov, V.; Uhlig, T.; Wagner, G. Influence of the Thickness of the Reaction Zone in Aluminum/Stainless Steel Brazed Joints on the Mechanical Properties. Metals 2021, 11 (2), 217. https://doi.org/10.3390/met11020217.
.Chao, R. M.; Yang, J. M., Lay, S. R. Interfacial Toughness for the Shipboard Aluminum/Steel Structural Transition Joint. Marine Structure 1997, 10 (5), 353–362. https://doi.org/10.1016/S0951-8339(96)00018-4.
.Meco, S.; Pardal, G.; Ganguly, S.; Williams, S.; McPherson, N. Application of Laser in Seam Welding of Dissimilar Steel to Aluminum Joints for Thick Structural Components. Optics and Lasers in Engineering 2015, 67, 22–30. https://doi.org/10.1016/j.optlaseng.2014.10.006.
.Basariya, M. I. R.; Mukhopadhyay, N. K. Structural and Mechanical Behaviour of Al-Fe Intermetallics. In Intermetallic Compounds - Formation and Applications; Aliofkhazraei, M., Ed.; InTech, 2018. https://doi.org/10.5772/intechopen.73944.
Copyright © 2021 Yijun Man, Dayou Pan, Shibo Liu Publishing time:2021-12-25
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