中文摘要：

采用双丝PMIG协同式高效焊接方法对板厚为60 mm的5A06铝合金进行了焊接试验,获得了优良的焊接接头,并对焊接接头进行了金相组织和力学性能分析.结果表明,母材保持轧制态纤维状组织,焊缝组织细密均匀,主要为α（Al）,β（Mg2Al3）及部分Mg2Si杂质相.接头平均抗拉强度和断后伸长率分别为306.17 MPa和11.93%,达到母材的90.5%和61.5%.对比接头各层显微组织和力学性能发现,热输入影响焊接接头热影响区宽度和力学性能.在焊接热输入最小的正面盖面层,焊缝组织更细,热影响区宽度更窄,试样力学性能更好.

英文摘要：

The feasibility of using synergetic high-efficiency tandem PMIG welding of 60 mm thick 5A06 aluminum alloy plate was investigated and sound weld joints were obtained. The metallographic structure and mechanical properties of the weld joint has been analyzed. The results show that the base metal keeps its original fibrous structure along the rolling direction,and the microstructure of the weld is fine and homogeneous,which mainly consists of α（ Al）,β（ Mg2Al3） and Mg2 Si. The average tensile strength and elongation of the weld joints is306. 17 MPa and 11. 93%,which is 90. 5% and 61. 5% of the base metal,respectively. The contrast of the microstructure and mechanical properties of the samples consisting different layers of the weld joint indicate that,the welding heat input influences the microstructure and mechanical property of the weld joint. With the decrease of the welding heat input the HAZ becomes narrower,the mechanical properties are better. The sample which contains the front surface layer has the smallest HAZ width and the best mechanical properties due to its smallest welding heat input.