| 摘要: |
| 为了改善镁合金焊接性差的特点,在对AZ31镁合金进行TIG焊接过程中加入纵向直流磁场,系统分析了不同励磁电流对焊接接头各部分的影响规律。结果发现,与不加磁场的情况相比,引入磁场后接头组织发生明显变化,焊缝组织得到细化,析出第二相的数量明显增多,并且大部分以球状颗粒的形式析出于枝晶界上;热影响区组织粗大的现象得到了很好的控制;从焊缝经熔合区向热影响区过渡时出现的共晶相数量有逐渐减少的趋势。通过X射线衍射结果可知,焊缝主要由α-Mg和β-Al12Mg17两相组成。在适当的焊接工艺参数条件下,当磁场电流为4A时,焊接接头的抗拉强度和硬度均显著提高,从而提高了AZ31镁合金焊接接头的综合力学性能。 |
| 关键词: 镁合金 纵向磁场 焊接接头 力学性能 |
| DOI： |
| 分类号: |
| 基金项目:辽宁省教育厅基金资助项目(05L298) |
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| Influence of longitudinal direct-current magnetic field on microstructure and property of AZ31 magnesium alloy TIG welded joint |
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LUO Jun, LIU Zhengjun, SU Yunhai, TIAN Yu
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Department of Material Science and Engineering, Shenyang University of Technology, Shenyang 110023, China
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| Abstract: |
| Longitudinal direct-current magnetic field is used in TIG (tungsten inert-gas)welding of AZ31 magnesium alloy to improve the welding property of magnesium alloy, the influence of different magnetic current on welded joint is analyzed.It is found that the joint is texture varied apparently after magnetic field is added. The microstructure in weld is refined.Lots of sphere-like second phase particles appear on the grain boundary and the quantity increases apparently, the microstructure in HAZ (heat-affected zone) is also refined.The quantity of second-phase is decreased from weld to HAZ.It is revealed that weld consists of α-Mg and β-Al12Mg17 by X-ray diffraction.With proper processing parameter, when the magnetic current is 4 A, the tensile strength and hardness of welded joint are increased apparently, thus the mechanical properties of welded joint of AZ31 magnesium alloy are increased. |
| Key words: magnesium alloy longitudinal magnetic field welded joint mechanical properties |
