不同激光焊方法对5A06铝合金中厚板组织及性能的影响

Effects of different laser welding methods on microstructure and properties of 5A06 aluminum alloy medium thickness plate

采用单激光焊和激光填丝焊研究了6 mm厚5A06铝合金中厚板的焊接性,分析了焊缝的形貌、力学性能和显微组织。结果表明:2种激光焊方法的焊缝形貌存在一定差异,激光填丝焊的焊缝鱼鳞纹更加均匀,单激光焊时的飞溅较多,焊缝熔宽更小且有咬边的现象;焊接接头的抗拉强度和显微硬度均低于母材的抗拉强度和显微硬度,激光填丝焊的抗拉强度能达到母材的80%以上,且其抗拉强度、伸长率和显微硬度均值均优于单激光焊的;焊缝区组织、熔合区和热影响区组织均分别为等轴枝晶、柱状晶和纤维状组织,熔合区与热影响区的界限明显,激光填丝焊焊缝区的等轴枝晶晶粒更细,熔合区的柱状晶数量占比更小。

The welding characteristics of 6 mm 5A06 aluminum alloy medium thickness plate were studied by single laser welding and laser filler wire welding,and the morphology,mechanical properties and microstructure of the weld were analyzed.The results showed that there was a certain difference in the weld morphology of the two laser welding methods.The fish scale pattern of laser wire filling weld was more uniform,the weld of single laser welding had more splash,the weld width was narrower and there were undercut phenomenon.The tensile strength and microhardness of welded joints were lower than those of the base metal,the tensile strength of laser wire filler welding could reach more than 80%of the base metal,and its tensile strength,elongation and microhardness were better than that of single laser welding.The microstructure of the weld zone,fusion zone and heat-affected zone were equiaxed dendrites,columnar crystals and fibrous structures respectively.There was a clear boundary between fusion zone and heat affected zone.The equiaxed dendrite grain of weld zone of laser wire filling welding was finer,and the proportion of columnar grain in fusion zone was smaller.