Microscopic Structure and Property of Double-Electrode Gas Metal Arc Welding of AZ31B Magnesium Allo

• 作 者: MA Guohong SHEN Xu PING Qiwen NIE Jun YE Jia
• 机 构: School of Mechanical Engineering, Nanchang University, Nanchang 330031, China;Electronic Lens Center
• 出 处: 上海交通大学学报（英文版）
• 发表日期: 2017年3期
• 关键词: double-electrode gas metal arc welding (DE-GMAW) dendrite eutectic reaction AZ31

This paper focuses on the research on double-electrode gas metal arc welding (DE-GMAW) of AZ31B magnesium alloy sheet with 2mm thickness.During the welding process,stable hybrid arc of metal inert gas (MIG) and tungsten inert gas (TIG) is employed as welding heat source.Optical and electron microscopes are used to observe the microstructures of the weld joint.X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) are employed to identify the components in fusion zone.Microhardness is also tested.When the MIG current is 80 A,the perfect weld joint is obtained,though figures of fish scales are observed in all joints in the research.The fusion zone is formed by dendrites,where β-Mg17(Al,Zn)12 is dispersed.The hardness in fusion zone and heat affected zone (HAZ) is lower than that in base metal (BM).The average Vickers hardness of fusion zone and HAZ is about 58 and 56 respectively,while the Vickers hardness of BM is about 63.