Microstructure and Mechanical Properties of Stainless Steel/Brass Joints Brazed by Sn-Electroplated Ag Brazing Filler Metals
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To develop a high-Sn-content AgCuZnSn brazing filler metal, the BAg50CuZn was used as the base filler metal and a Sn layer was electroplated upon it. Then, the 304 stainless steel and the H62 brass were induction-brazed with the Sn-plated brazing filler metals. The microstructures of the joints were examined with an optical microscope, a scanning electron microscope and an x-ray diffractometer. The corresponding mechanical properties were obtained with a universal tensile testing machine. The results indicated that the induction brazed joints consisted of the Ag phase, the Cu phase and the CuZn phase. When the content of Sn in the Sn-plated Ag brazing filler metal was 6.0 or 7.2 wt.%, the Cu5Zn8, the Cu41Sn11 and the Ag3Sn phases appeared in the brazed joint. The tensile strength of the joints brazed with the Sn-plated filler metal was higher compared to the joints with the base filler metal. When the content of Sn was 6.0 wt.%, the highest tensile strength of the joint reached to 395 MPa. The joint fractures presented a brittle mode, mixed with a low amount of ductile fracture, when the content of Sn exceeded 6.0 wt.%.
Keywordsdissimilar joint induction brazing microstructure silver-based filler metal Sn coating tensile strength
This research is supported by the National Natural Science Foundation of China (Grant No. 51705151), the Natural Science Foundation of Henan Province in China (Grant No. 162300410191), the Key Research Project of Higher Education in Henan Province in China (Grant No. 17A430021) and the Doctoral Fund of North China University of Water Resources and Electric Power (Grant No. 201704001).
- 3.P.C. Wingert and C.H. Leung, The Development of Silver-Based Cadmium-free Contact Materials, J. Alloys Compd., 2004, 72, p 148–157Google Scholar
- 4.P.M. Roberts, Recent Developments in Cadmium-Free Silver Brazing Alloys, Weld. J., 1978, 57, p 23–30Google Scholar
- 5.Z.Y. Lü, L.Y. Han, and T.L. Zhang, Study on the Quality of High Frequency Induction Brazing Joints of Stainless Steel and Brass, Weld. Technol., 2013, 42(3), p 48–50Google Scholar
- 6.P.F. Timmins, The Mechanism of Tough-pitch Copper Embitterment by Silver Brazing Alloys, Weld. J., 1990, 69(10), p 378s–419sGoogle Scholar
- 11.J. Ma, W.M. Long, P. He, P. Xue, and M.F. Wu, Effect of Gallium Addition on Microstructure and Properties of Ag-Cu-Zn-Sn Alloys, China Weld. (English Edition), 2015, 24(3), p 6–10Google Scholar
- 16.S. Daniel, W. Gunther, and S. Sebastian, Development of Ag-Cu-Zn-Sn Brazing Filler Metals with a 10weigh-% Reduction of Silver and Liquids Temperature, China Weld. (English Edition), 2014, 23(4), p 25–31Google Scholar
- 18.X.X. Wang, W.M. Long, J. Ma, and D.F. Lv, Effect of Electroplated Tin Coating on Properties of BAg50CuZn Brazing Filler Metal, Trans. China Weld. Inst., 2014, 35(9), p 61–64Google Scholar
- 19.X.X. Wang, Q.C. Li, W.M. Long, K.B. Nie, and M.Q. Tang, Effect of Heat Diffusion Process on the Interface Microstructure and Melting Characteristic of Brazing Filler Metals with Tin Coatings, Trans. China Weld. Inst., 2016, 37(5), p 89–92Google Scholar
- 20.X.X. Wang, G.X. Zhang, W.M. Long, Y.X. Shen, and Y.Y. Pei, Experimental Research of Tin Brush Electroplated on Ag45CuZn Brazing Filler Metal, Rare Met. Mater. Eng., 2013, 42(11), p 2394–2399Google Scholar
- 21.P. Villars, A. Prince, and H. Okamoto, Handbook of Ternary Alloy Phase Diagrams, ASM International, Russell Township, 1995Google Scholar
- 22.T.B. Massalski and H. Okamoto, Binary Alloy Phase Diagrams, ASM International, Russell Township, 1990Google Scholar