变形镁合金AM60焊接接头的组织与性能

Microstructure and Properties of Welded Joints for Wrought Magnesium Alloy AM60

以AM60变形镁合金薄板为研究对象,分别采用TIG焊和CO2激光焊两种方法进行焊接,探讨在不同工艺条件下材料的焊接特点,并从宏观成形、微观组织、力学性能等方面对焊接质量进行评价。试验结果表明:在工艺参数合适的条件下,加焊丝TIG焊和激光焊均能获得成形较好的焊接接头;TIG焊接头热影响区较宽,焊缝深宽比小,而激光焊时热影响区不明显,焊缝深宽比大;两种焊接方法所获得的焊缝区组织均为均匀的等轴晶,但激光焊时焊缝组织更细,从而使接头抗拉强度大幅度提高,达到母材的94%左右。

The experiment of tungsten inert gas （TIG） welding and laser beam welding to wrought magnesium alloy AM60 plates was conducted. The suitability of the different processes was analyzed by observing the weld appearance, studying the microstructure and measuring the mechanical properties of the joint. The results show that a favorable weld can be obtained under the suitable parameters by laser beam welding or tungsten inert gas （T/G） welding with filler metal. The TIG welded joint has a wider HAZ, and the laser welded joint has a narrower one. The aspect ratio of TIG weld is much lower than that of laser weld. The microstructure is uniform equiaxed grain in weld zone. The ultimate tensile strength of laser welded joint increases due to the finer grains in weld zone, which is up to 94% of the base metal.