| 摘要: |
| 利用激光-电弧(TIG)复合热源的能量密度梯度分布特征,通过添加镍箔夹层,开展了AZ31B镁合金与Q235钢对接熔化焊研究.采用电子万能拉伸试验机、扫描电镜、X射线衍射仪等手段分析了焊接接头的组织特征以及力学性能.结果表明,采用该方法能够实现镁/钢异质金属对接焊接成形,界面结合良好,接头钢侧形成了由Fe,Ni,Al元素构成的明显过渡区,焊缝主要由α-Mg和大量弥散分布的白色AlNi相颗粒组成.焊接接头断裂在钢侧界面附近,断口形貌呈现准解理断裂特征,接头平均抗拉强度为232 MPa,可达镁合金母材的90%. |
| 关键词: 激光-电弧复合热源 对接焊 镁合金 钢 镍夹层 |
| DOI： |
| 分类号: |
| 基金项目:国家科技重大专项资助项目(2012zx04008031) |
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| Study on butt fusion welding characteristics of AZ31B magnesium alloy to steel by hybrid laser-TIG welding with Ni interlayer |
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SONG Gang1, HU Guanglong1, REN Daxin2, LIU Liming1
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1.Key Laboratory of Liaoning Advanced Welding and Joining Technology, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;2.Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams(Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China
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| Abstract: |
| Investigations on butt fusion welding characteristics of AZ31B magnesium alloy to steel with Ni interlayer were carried out by utilizing the gradient energy density characteristic of laser-TIG heat source. The tensile strength and microstructure of the joint were examined by electronic tension machine, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results indicated that magnesium alloy can be butt joined to steel by hybrid laser-TIG welding with good Mg/Fe interface by using Ni foil as the interlayer. At the same time, tests showed that a distinct transition zone consisting of Fe, Ni and Al elements forms at the steel side nearby the interface; the microstructure of the joint is mainly composed of α-Mg and a large number of small white particles which are mainly composed of AlNi phase and dispersively distributed. The joint fractures nearby the Mg/Fe interface and the fracture surface shows a typical quasi-cleavage crack. The average of the joint tensile strength is 232 MPa, which is about 90% of the magnesium base metal. |
| Key words: hybrid laser-TIG heat source butt joint magnesium alloy steel Ni interlayer |
