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 80A, 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.
MA Guohong1* (马国红), SHEN Xu1 (沈旭), PING Qiwen1 (平齐文),NIE Jun1 (聂军), YE Jia2 (叶佳)
. Microscopic Structure and Property of Double-Electrode Gas Metal Arc Welding of AZ31B Magnesium Alloy[J]. Journal of Shanghai Jiaotong University(Science), 2017
, 22(3)
: 286
-290
.
DOI: 10.1007/s12204-017-1834-4
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