铝/镀镍钢异种材料摆动激光熔钎焊接头组织性能  

Microstructure and Properties of Rotating Laser Welded⁃Brazed Aluminum/Nickel⁃Plated Steel Dissimilar Joint

作　　者：刘永洪 蔡创 谢佳 张冰冰 余杰 黄嘉森 Liu Yonghong;Cai Chuang;Xie Jia;Zhang Bingbing;Yu Jie;Huang Jiasen(Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China)

机构地区：[1]西南交通大学材料科学与工程学院材料先进技术教育部重点实验室,四川成都610031

出　　处：《中国激光》2024年第12期41-49,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(52375386,51805456);先进焊接与连接国家重点实验室开放课题研究基金(AWJ-23M18)。

摘　　要：界面金属间化合物的厚度和种类是影响铝/钢异种材料激光熔钎焊接头性能的关键。研究了不同摆动参数下接头金属间化合物(IMCs)的厚度和种类,并进一步分析了不同摆动参数下接头的拉伸性能及断口形貌。结果表明,摆动激光可以改善铝/钢异种材料激光熔钎焊接头界面金属间化合物的厚度和相组成。未加摆动激光时,在界面形成了厚度约为8.45μm的两层IMCs,焊缝侧IMCs为τ_(5)-(Fe,Ni)_(1.8)Al_(7.2)Si,钢侧IMCs为θ-(Fe,Ni)(Al,Si)_(3)。当激光摆动直径为2 mm、频率为30 Hz时,IMCs的分布更加连续均匀,厚度约为2.21μm,界面层组织为τ_(5)-(Fe,Ni)_(1.8)Al_(7.2)Si,最优接头线载荷为289.1 N/mm,比未加摆动激光时的接头线载荷提高了约33.9%。Objective The use of low-density lightweight materials,such as aluminum alloys,instead of traditional steel,titanium,and other materials to form a dissimilar material composite structure is an important way to achieve a light weight.Because of the different physical and chemical properties of aluminum alloys and steel,it is difficult to join aluminum and steel by laser welding-brazing.Brittle intermetallic compounds(IMCs)in the interface layer are easily produced owing to the small solid solubility between iron and aluminum.In this research,a rotating laser is applied to improve the temperature distribution and optimize the interface reaction.Based on the analysis of the morphology,type,and thickness of the interface layer of the aluminum/steel laser welding-brazing joint under different rotating parameters,the mechanical properties of the aluminum/steel welded joint are studied by a tensile test,and the fracture morphology and fracture mode of the joint are also investigated.Methods The test materials are a 304 stainless-steel plate with a size of 100.0 mm×80.0 mm×0.9 mm and a 6061-T6 aluminum alloy sheet with a size of 100.0 mm×80.0 mm×1.2 mm.AlSi12 is used as filler wire.A fiber laser is used as the heat source.High-purity argon(volume fraction of 99.99%)with a gas flow rate of 25 L/min is used as the protective gas.After welding,the cross-sectional morphology of the weld is observed by using a metallographic microscope.A scanning electron microscope(SEM)is used to analyze the morphology and thickness of the IMC layer.The chemical composition of the interface layer is detected using an energy-dispersive X-ray spectroscope(EDS)system integrated with the SEM.The mechanical performance of the joint is represented by the line load.The fracture morphology is observed using the secondary electron detector of the SEM.Results and Discussions After the addition of the rotating laser,the thickness of IMCs composed of θ-(Fe,Ni)(Al,Si)_(3) and τ_(5)-(Fe,Ni)_(1.8)Al_(7.2)Si is significantly reduced,and the uniformity

关 键 词：激光技术 铝/钢激光熔钎焊 摆动激光 金属间化合物 力学性能 

分 类 号：TG457.1[金属学及工艺—焊接]