Effect of input current modes on intermetallic layer and mechanical property of aluminum-steel lap joint obtained by gas metal arc welding
Effect of input current modes on intermetallic layer and mechanical property of aluminum-steel lap joint obtained by gas metal arc welding
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DOI：
10.1016/j.msea.2013.04.097
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发表时间：
2013-08-20
期刊：
影响因子：
6.4
通讯作者：
Wu, Yixiong
中科院分区：
文献类型：
--
作者：
Su, Yongchao;Hua, Xueming;Wu, Yixiong
研究了铝-钢直流脉冲熔化极气体保护焊（DPG）和交流双脉冲熔化极气体保护焊（ADG）搭接接头。被焊接的基底金属是1 mm厚的5052铝合金板和1 mm厚的镀锌低碳钢板，填充金属是1.2mm 4047。通过对钢/铝界面相和力学强度的表征，研究了不同焊接工艺对接头性能的影响。结果表明，焊接热输入量决定了由Fe_2Al_5、FeAl（3）和Fe_3Al组成的金属间化合物层的厚度以及Fe元素从钢中向焊缝的扩散。采用ADG工艺制备的铝-铁搭接剪切试样断裂于铝母材或焊缝处，平均抗拉强度为201 MPa。另一方面，由DPG工艺产生的接头的所有搭接剪切试样均沿着Fe 2Al 5亚层与钢板之间的界面断裂，平均UTS为115 MPa。与DPG工艺相比，ADG工艺由于减少了热输入而使金属间化合物层变薄，从而提高了接头强度，说明循环极性切换和二次低频电流脉冲可以有效地减少Fe-Al异种材料的热输入，这意味着ADG工艺更适合于制备坚固的Fe-Al搭接接头。(C)2013爱思唯尔有限公司版权所有。
This paper studies Al-steel lap joints resulted from direct-current pulsed gas metal arc welding (DPG) and alternate-current double-pulse gas metal arc welding (ADG). Base metals being welded are 1 mm thick 5052 Al alloy sheet and 1 mm thick galvanized mild steel sheet with filler metal being 1.2 mm 4047. Effect of the different welding processes on joint properties is studied through characterization of the steel/Al interphases and mechanical strength. It is found that the thickness of intermetallic compound layer composed of Fe2Al5, FeAl(3)and Fe3Al, and the diffusion of Fe element from steel to weld seam are dependent on the amount of welding heat input. Lap shear samples of Al-Fe joints resulted from the ADG process fractured at Al base metal or weld seam with average ultimate tensile strength (UTS) of 201 MPa. On the other hand, all lap shear samples of the joints resulted from DPG process fractured along the interphase between the Fe2Al5 sub-layer and the steel sheet with average UTS of 115 MPa. ADG process offers higher joint strength than that offered by DPG process due to thinner intermetallic compounds layer caused by the reduced heat input, illustrating that cyclic polarity switching and a secondary low frequency current pulse can effectively reduce the heat input in joining Fe-Al dissimilar materials, which means the ADG process is much more feasible for making robust Fe-Al lap joints. (C) 2013 Elsevier B.V. All rights reserved.