铜/镍中间层对铝/钢激光-MIG搭接焊界面的影响

Influence of Cu/Ni Interlayer on Interface of Laser-MIG Lap Welding of Al/Fe

针对铝/钢激光-MIG搭接焊接头存在硬度高而脆性过高的问题,采用激光-MIG搭接焊方法,对不锈钢304和铝合金5052进行焊接,研究铜/镍中间层对焊接接头界面的作用。分别利用SEM/EDS方法和显微硬度计得到焊接接头界面的金属间化合物分布和硬度分布情况,分析添加铜/镍中间层后焊接接头界面的变化情况。研究结果表明,Al-Cu金属间化合物和Al-Ni金属间化合物的产生减少了金属间化合物的厚度,铝/钢接头界面处存在较厚的硬化层。添加铜/镍后,接头界面的硬化层厚度分别降低75.00%和87.50%,平均显微硬度分别降低9.60%和4.60%。最后,添加铜/镍中间层,有利于降低接头的脆硬性。

Aiming at the problem of the high brittleness and hardness of the aluminum/steel laser-MIG lap joint,the laser MIG lap welding method was used to weld stainless steel 304 and aluminum alloy 5052,and the effect of Cu/Ni interlayer on the interface of the welded joint was studied.The distribution of intermetallic compound and hardness at the interface of welded joint were obtained by SEM/EDS and microhardness tester respectively,and the change of interface after adding Cu/Ni interlayer was analyzed.The results show that the production of Al-Cu-IMCs and Al-Ni-IMCs reduces the thickness of the compound.There is a thick hardening layer at the interface of Al/steel joint.After adding Cu/Ni,the thickness of the hardened layer of the joint interface reduces by 75.00%and 87.50%respectively,the average microhardness reduces by 9.60%and 4.60%respectively.Finally,the addition of Cu/Ni interlayer is beneficial to reducing the brittleness and hardness of the joint.