Effect of Zn Coating and Al–Zn Coating on Al/Steel Joints by Vacuum Electron Beam Welding
Effect of Zn Coating and Al–Zn Coating on Al/Steel Joints by Vacuum Electron Beam Welding
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DOI：
10.1007/s12666-019-01691-3
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发表时间：
2019-09
影响因子：
1.6
通讯作者：
R. Xu;Z. C. Wei;F. S. Li
中科院分区：
文献类型：
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作者：
R. Xu;Z. C. Wei;F. S. Li
采用真空电子束焊接方法，成功地将厚度为2 mm的6061铝合金板材与镀锌和镀锌的Q235钢板进行了真空电子束焊接，并在界面形成了Fe-Al金属间化合物(IMCs)层。与Al/非涂层钢接头相比，Al/涂层钢接头具有更好的搭接剪切拉伸值，分别提高了约37%和29%，从1.83提高到2.51kN(铝/锌涂层钢接头)，提高到2.36kN(铝/铝锌涂层接头)。这主要是由于铝液在钢表面具有更好的润湿性和铺展性，从而延长了有效结合长度。在所有情况下，失效都发生在沿Fe2Al5层的Al/钢界面。结果表明，由涂层组成的锌元素对改善金属间化合物的润湿性和断裂载荷有积极的作用，其主要影响因素是助熔剂、改变气氛和抑制金属间化合物的生长。另一方面，铝锌涂层中锌元素含量越少，其润湿性越差。然而，含铝锌涂层在减少真空下锌涂层的汽化方面取得了较好的效果。
Two-mm-thick 6061 Al alloy plate to non-coated and coated Q235 steel plates, which were covered with Zn coating and Al–Zn coating, respectively, were successfully vacuum electron beam-welded, and a Fe–Al intermetallic compounds (IMCs) layer was formed at the interface. Compared with the Al/non-coated steel joint, Al/coated steel joints offered better lap shear tensile values, which were increased by around 37% and 29% from 1.83 to 2.51 kN (Al/Zn-coated steel joint), and to 2.36 kN (Al/Al–Zn-coated joint). The increase was mainly attributed to a longer effective bonding length through a better wettability and spreadability of liquid Al on steel surface. In all the cases, failure occurred at the Al/steel interface along the Fe2Al5layer. It can be concluded that Zn element, consisting of coatings, has a positive influence on the improvement of wettability and fracture load value, and the main factors are acting as flux, changing atmosphere and reducing IMCs growth. On the other hand, Al–Zn coating, containing less Zn element, leads to a relatively worse wettability. However, Al-containing Zn coating can receive a productive result in reducing the vaporization of Zn coating in vacuum.