Interfacial Microstructure of Magnetic Pressure Seam Welded Al-Fe, Al-Ni and Al-Cu Lap Joints
Interfacial Microstructure of Magnetic Pressure Seam Welded Al-Fe, Al-Ni and Al-Cu Lap Joints
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DOI：
10.4028/www.scientific.net/msf.519-521.1145
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发表时间：
2006-07
期刊：
影响因子：
--
通讯作者：
Mitsuhiro Watanabe;S. Kumai;T. Aizawa
中科院分区：
文献类型：
--
作者：
Mitsuhiro Watanabe;S. Kumai;T. Aizawa
采用一种新的焊接方法--磁力压力缝焊对铝-铁、铝-镍、铝-铜异种金属进行搭接连接。磁压缝焊电路由电容器、放电间隙开关和板式线圈组成。将重叠的金属板放置在线圈上。当来自储能电容器组的冲击电流通过线圈时，线圈周围突然产生高密度磁通。产生的高密度磁通线穿过重叠板的端部。涡电流主要在Al板内部感应，因为其具有高导电性。在板中产生的焦耳热和从Al侧施加的磁压力都促进了搭接板的连接。焊接通常在10 μs内完成。这导致除了焊接界面周围的区域之外，母板中的微观结构变化非常小。对于每种金属组合，获得了强搭接接头，并且在焊接区域没有发生拉伸断裂。在焊缝界面处观察到特征性的波状形态。在焊缝界面处还观察到一个中间相层。TEM观察表明，中间层由细小的Al晶粒和分散在Al晶粒之间的金属间化合物颗粒组成。为了阐明该方法的焊接机理，对界面波的生长方向、波长和振幅与焊接条件的关系进行了深入的研究。
A new welding method, magnetic pressure seam welding, was used to lap join dissimilar metals (Al-Fe, Al-Ni and Al-Cu). The circuit for magnetic pressure seam welding consists of a capacitor, an electric discharge gap switch, and a plate-type coil. The overlapped metal plates are placed over the coil. When an impulse current from an energy-storage capacitor bank passes through the coil, a high-density magnetic flux is suddenly generated around the coil. The generated high-density magnetic flux lines cross the end of the overlapped plates. Eddy currents are induced mainly inside the Al plate because it has a high electrical conductivity. Both the Joule heat generated in the plates and the magnetic pressure applied from the Al side promote the joining of the lapped plates. The welding is normally achieved within 10 μs. This results in very little microstructural change in the parent plates aside from the area around the weld interface. Strong lap joints were obtained for every metal combination and no tensile fracture took place in the weld region. A characteristic wavy morphology was observed at the weld interface. An intermediate phase layer was also observed at the weld interface. TEM observation revealed that the intermediate layer consisted of fine Al grains and intermetallic compound particles dispersed among the Al grains. The growth direction of the wave, the welding condition dependency of the wavelength and the amplitude of the interfacial wave were intensively investigated in order to clarify the welding mechanism of this method.