Interfacial Bonding Mechanism and Fatigue Performance of Al/Steel Dissimilar Welds Fabricated via Friction Stir Brazing

doi:10.3901/JME.2024.22.130

Abstract

Abstract: Based on character of friction stir welding such as low temperature and severe plastic deformation, the tool only stir in the top Al alloy, which promotes thermodynamic couple, coupling with the interlayer of zinc coating on the steels to improve interfacial bonding and fatigue performance of Al/steel dissimilar welds. The investigation indicated that making use of thermodynamic couple mechanism, the zinc coating improved weldability of Al alloy and steel. As a brazing filler metal, the zinc coating layer avoides direct contact between Al alloy and steel, and thus avoides the formation of intermetallic compound. The zinc material gathered around the retreating side on the Al/steel interface, and typical eutectic structure of Al and Zn are formed on the advancing side at the Al/steel interface. The zinc material is squeezed outside of the stirring zone, where nano scaled Fe₃Al Fe₄Al₁₃ are identified, which are formed during the hot-dipping process. Lap shear strength of the friction stir brazed Al/steel dissimilar welds are stable, the maximum lap shear strength and elongation reached 333.8 N/mm and 11.33%, respectively. Under the fatigue load, three different failure modes are observed：interfacial failure under higher load, mixed failure under medium load, base metal failure and interfacial failure under lower load. The cycle can reach 2×10⁶ without failure under a load of 2.64 kN.

Key words: friction stir brazing, Al alloys, zinc coated steels, interfacial bonding mechanism, fatigue performance

CLC Number:

TG156

SHEN Zhikang, WANG Bo, YANG Yi, GUAN Yuehui, ZHOU Ping, HOU Wentao, PIAO Zhongyu, LIU Xiaochao, HUANG Guoqiang, YANG Xiawei, CHEN Haiyan, TIAN Yanhong, LI Wenya, LI Huijun. Interfacial Bonding Mechanism and Fatigue Performance of Al/Steel Dissimilar Welds Fabricated via Friction Stir Brazing[J]. Journal of Mechanical Engineering, 2024, 60(22): 130-138.

References

[1] 武传松，吕学奇，宿浩，等. 铝-镁异质合金搅拌摩擦焊接成形的研究进展[J]. 机械工程学报，2020，56(6)：4-17. WU Chuansong, LÜ Xueqi，SU Hao，et al. Research progress in dissimilar friction stir welding of aluminium/magnesium alloys[J]. Journal of Mechanical Engineering，2020，56(6)：4-17.
[2] 薛松柏，王博，张亮，等. 中国近十年绿色焊接技术研究进展[J]. 材料导报，2019，33(17)：2813-2830. XUE Songbai，WANG Bo，ZHANG Liang，et al. Development of green welding technology in China during the past decade[J]. Materials Reports，2019，33(17)：2813-2830.
[3] 李亚江，吴娜. 钢/铝异种金属焊接的研究现状[J]. 焊接，2010，8(3)：5-12，68. LI Yajiang，WU Na. Current research status of dissimilar materials welding between steel and aluminum-welding characteristic，brazing and press welding[J]. Welding & Joining，2010，8(3)：5-12，68.
[4] 冯吉才. 异种材料连接研究进展[J]. 航空学报，2022，43(2)：626413. FENG Jicai. Research progress on dissimilar materials joining[J]. Acta Aeronautica et Astronautica Sinica，2022，43(2)：626413.
[5] 王晓虹，谷晓燕，孙大千. 钢/铝异种金属激光焊接头界面特性的研究[J]. 机械工程学报，2017，53(4)：26-33. WANG Xiaohong，GU Xiaoyan，SUN Daqian. Research on interface characteristic of laser welding joints of steel/aluminum dissimilar materials[J]. Journal of Mechanical Engineering，2017，53(4)：26-33.
[6] 黄鹏飞，卢振洋，高文宁，等. 钢铝异种金属的低能量焊接法[J]. 机械工程学报，2009(11)：295-299. HUANG Pengfei，LU Zhenyang，GAO Wenning，et al. Low energy welding technology in bonding steel with aluminum[J]. Journal of Mechanical Engineering，2009(11)：295-299.
[7] 汤祖阳，王亚强，董红刚. 轻质异种材料搅拌摩擦点焊技术研究进展[J]. 机械工程学报，2020，56(6)：147-158. TANG Zuyang，WANG Yaqiang，DONG Honggang. Progress of the friction stir spot welding in lightweight dissimilar materials[J]. Journal of Mechanical Engineering，2020，56(6)：147-158.
[8] 秦国梁，耿培皓，陈永，等. 铝/钢异种金属MIG电弧熔-钎焊接界面应力演变数值分析[J]. 机械工程学报，2021，57(2)：87-96. QIN Guoliang，GENG Peihao，CHEN Yong，et al. Numerical analysis of stress evolution in MIG arc brazing-fusion welding of Al alloy to galvanized steel plate[J]. Journal of Mechanical Engineering，2021，57(2)：87-96.
[9] LIU X，LUO J，BAO W，et al. Improved mechanical properties of SUS304/AA5083 dissimilar joint by laser ablation pretreatment in vortex-friction stir lap welding[J]. Crystals，2023，13(9)：1336.
[10] SHEN Z，CHEN Y，HAGHSHENAS M，et al. Role of welding parameters on interfacial bonding in dissimilar steel/aluminum friction stir welds[J]. Engineering Science and Technology，an International Journal，2015，18(2)：270-277.
[11] CHEN Y，NAKATA K. Effect of the surface state of steel on the microstructure and mechanical properties of dissimilar metal lap joints of aluminum and steel by friction stir welding[J]. Metallurgical and Materials Transactions A，2008，39：1985-1992.
[12] SHEN Z，CHEN J，DING Y，et al. Role of interfacial reaction on the mechanical performance of Al/steel dissimilar refill friction stir spot welds[J]. Science and Technology of Welding and Joining，2018，23(6)：462-477.
[13] SHEN Z，DING Y，CHEN J，et al. Interfacial bonding mechanism in Al/coated steel dissimilar refill friction stir spot welds[J]. Journal of Materials Science & Technology，2019，35(6)：1027-1038.
[14] SHEN Z，DING Y，CHENJ，et al. Comparison of fatigue behavior in Mg/Mg similar and Mg/steel dissimilar refill friction stir spot welds[J]. International Journal of Fatigue，2016，92：78-86.
[15] ZHANG G，SU W，ZHANG J，et al. Friction stir brazing：A novel process for fabricating Al/steel layered composite and for dissimilar joining of Al to steel[J]. Metallurgical and Materials Transactions A，2011，42：2850-2861.
[16] ZHANG G，ZHANG K，GUO Y，et al. A comparative study of friction stir brazing and furnace brazing of dissimilar metal Al and Cu plates[J]. Metallography，Microstructure，and Analysis，2014，3：272-280.
[17] ZHANG T，HAO Z，WANG K，et al. Effect of Ni interlayer on interfacial microstructure and fatigue behavior of friction stir lap welded 6061 aluminum alloy and QP1180 steel[J]. International Journal of Fatigue，2024，180：108096.
[18] 王蕾. 铝/钢异种金属电阻点焊焊接性及接头疲劳行为的研究[D]. 长春：吉林大学，2022. WANG Lei. Study on weldability and joint fatigue behavior of al/steel dissimilar metals resistance spot welding[D]. Changchun：Jilin University，2022.
[19] 李微，肖国源，陈辉涛，等. 渗铝复合激光冲击对321不锈钢腐蚀疲劳性能的影响[J]. 中国表面工程，2022，34(2)：140-151. LI Wei，XIAO Guoyuan，CHEN Huitao，et al. Effect of aluminizing and laser shock peening on corrosion fatigue properties of 321 stainless steel[J]. China Surface Engineering，2022，34(2)：140-151.
[20] MARDER A R. The metallurgy of zinc-coated steel[J]. Progress in Materials Science，2000，45(3)：191-271.
[21] CHEN Y，CHEN J，AMIRKHIZ S，et al. Microstructures and properties of Mg alloy/DP600 steel dissimilar refill friction stir spot welds[J]. Science and Technology of Welding and Joining，2015，20(6)：494-501.