不同工作模式下7075铝合金/镀锌钢冷金属过渡熔钎焊接头组织及性能研究
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摘要
采用Fronius TPS5000i系列CMT焊机的CMT-ADV、CMT和CMT-P三种工作模式对7075高强铝合金/镀锌钢进行熔钎焊试验。通过光学显微镜、扫描电镜、能谱分析和拉伸试验研究不同工作模式对接头组织及性能的影响。试验结果表明:三种模式均可获得成形良好的焊缝,在焊接速度和送丝速度相同的条件下,CMT-ADV模式接头高度最高;CMT-P模式接头宽度最大。接头均可分为富锌区、界面区、焊缝区和热影响区,焊缝区组织为树枝晶。CMT-ADV和CMT模式接头界面区厚度分别为2μm和4μm,组织为FeAl_3;CMT-P模式接头界面区厚度达到10μm,由铝侧的FeAl_3和钢侧的Fe_2Al_5组成。CMT-P模式接头承受载荷最大,达到7668 N,断裂在焊接接头熔合区附近。
The welding-brazing tests of 7075 high strength aluminum alloy/galvanized steel were carried out by Fronius TPS5000 i series CMT welder under three working modes of CMT-ADV, CMT and CMT-P. The effects of different working modes on the microstructure and properties of the joint were studied by optical microscope, SEM, EDS and tensile test. The results show that well formed weld can be obtained under three modes. When the welding speed and wire feeding speed are the same, the joint height is the highest under the CMT-ADV mode, and the width of the joint is the largest under the CMT-P mode. The joint can be divided into zinc rich zone, interface zone, weld zone and HAZ, and the microstructure of the weld zone is dendrite. The thickness of joint interface under CMT-ADV and CMT modes is 2 μm and 4 μm respectively, and the microstructure is FeAl_3. The thickness of joint interface under CMT-P mode is 10 μm, the microstructure is composed of FeAl_3 at the aluminum side and Fe_2Al_5 at the steel side. Under the CMT-P mode, the load is maximum and reaches 7668 N, and it breaks near the fusion zone of the welded joint.
The welding-brazing tests of 7075 high strength aluminum alloy/galvanized steel were carried out by Fronius TPS5000 i series CMT welder under three working modes of CMT-ADV, CMT and CMT-P. The effects of different working modes on the microstructure and properties of the joint were studied by optical microscope, SEM, EDS and tensile test. The results show that well formed weld can be obtained under three modes. When the welding speed and wire feeding speed are the same, the joint height is the highest under the CMT-ADV mode, and the width of the joint is the largest under the CMT-P mode. The joint can be divided into zinc rich zone, interface zone, weld zone and HAZ, and the microstructure of the weld zone is dendrite. The thickness of joint interface under CMT-ADV and CMT modes is 2 μm and 4 μm respectively, and the microstructure is FeAl_3. The thickness of joint interface under CMT-P mode is 10 μm, the microstructure is composed of FeAl_3 at the aluminum side and Fe_2Al_5 at the steel side. Under the CMT-P mode, the load is maximum and reaches 7668 N, and it breaks near the fusion zone of the welded joint.
引文
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[2]Pang Jie,Hu Shengsun,Shen junqi,et al.Arc characteristics and metal transfer behavior of CMT+P welding process[J].Journal of Materials Processing Technology,2016,238:212-217.
[3]Cong Baoqiang,Ouyang Ruijie,Qi Baojin et al.Influence of cold metal transfer process and its heat input on weld bead geometry and porosity of aluminum-copper alloy welds[J].Rare Metal Materials and Engineering,2016,45(3):606-611.
[4]石常亮,何鹏,冯吉才,等.铝/镀锌钢板CMT熔钎焊界面区组织与接头性能[J].焊接学报,2006,27(12):61-64.
[5]从保强,欧阳瑞洁,乔柳平,等.不同CMT工艺2014-T6焊缝成形及气孔分析[J].焊接学报,2015,36(5):37-40.