5A06铝合金激光填丝焊接头组织性能分析

Microstructure and Mechanical Properties of Laser Welding 5A06 Aluminum with Filling Wire

对1.2mm厚5A06铝合金薄板激光填丝焊接接头组织与性能进行了研究。结果表明,激光焊接过程中填丝使接头显微组织相对粗大和硬度略有降低;同时,填丝淡化焊缝中心柱状晶相对生长所产生的结晶交界面,改善咬边、焊塌等成型不良缺陷,显著提高激光焊接头的拉伸性能,使接头抗拉强度提高10%左右,延伸率提高10%～30%;拉伸断口呈韧性断裂。同时推出填丝可以增加材料对激光的吸收率。

The microstructure of laser welding joint with filling wire of 5A06 aluminum alloy sheet with 1.2mm thickness was observed. The mechanical properties, such as the microhardness and the tensile properties at the room temperature were also tested, meanwhile the fraetography was observed. The result indicates that the microstructure is a little coarser and the microhardness is slightly lower than the joint without filling wire. Meanwhile, the crystallized interface of opposite columnar grains growing in weld centre is weakened and the welding defects （such as undercut, slump and so on） are improved, so the joint with filling wire has better tensile property than joint without filling wire, which includes that the tensile strength can be increased of nearly 10% and the elongation is improved about 10%-30%. Besides, the tensile fractography of joint with filling wire is presented by ductile rupture. In addition, the laser absorptivity of materials can be increased by filling wire during the laser welding course.