焊丝成分对铝-铜异种金属熔钎焊接头钎焊界面组织与接头力学性能的影响

摘要

采用脉冲旁路耦合电弧MIG熔钎焊方法对1060纯铝和T2紫铜进行了对接焊,选用ER1100、ER5356、ER4043和ER4047四种焊丝为填充材料,研究了焊丝成分对焊接接头微观组织、金属间化合物层的厚度以及力学性能的影响规律.结果表明:4种焊丝的焊接接头均由铝侧熔合区、焊缝区和铜侧钎焊区组成,其中铜侧钎焊区又可细分为金属间化合物层区和Al-Cu共晶区两部分.焊丝中Si元素的加入可以起到阻碍铝铜原子互扩散、抑制铝铜金属间化合物生长、提高焊缝显微硬度以及抗拉强度等作用;而加入Mg元素,其效果不明显.%Dissimilar metals of 1060 aluminum and T2 copper were joined with butt joint by pulsed double electrode gas metal arc welding-brazing.ER1100,ER5356,ER4043 and ER4047 filler wires were used as filler materials,respectively.The effects of composition of filler wires on the mechanical properties,the thickness of intermetallic compound layer and microstructure of joints were studied.The results show that the four welding joints are composed of fusion zone of the aluminum side,the weld zone,brazing zone of the copper side,and brazing zone was divided into two parts,namely,Al-Cu eutectic zone and Al-Cu intermetallic compounds layer zone.Si element in the filler wires is able to discourage the diffusion of Al and Cu atoms,which controls the growth of intermetallic compounds between Al and Cu as well as increase the microhardness and tensile strength of weld seam.While the addition of Mg has no obvious effect.