Investigation on Double Wire Metal Inert Gas Welding of A7N01-T4 Aluminum Alloy in High-Speed Welding

Four-millimeter thick A7N01-T4 aluminum alloy plates were welded by double wire metal inert gas welding (DWMW) in high welding speeds, ranging from 1100 to 1250 mm/min. The results show that a sound joint could be obtained at a high speed of 1200 mm/min using DWMW. The weld zone (WZ) in the joint sh...

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Bibliographic Details
Main Authors: Wei Zhicheng, Xu Rongzheng, Li Hui, Hou Yanxi, Guo Xuming
Format: Article
Language:English
Published: De Gruyter 2019-02-01
Series:High Temperature Materials and Processes
Subjects:
Online Access:https://doi.org/10.1515/htmp-2018-0073
Description
Summary:Four-millimeter thick A7N01-T4 aluminum alloy plates were welded by double wire metal inert gas welding (DWMW) in high welding speeds, ranging from 1100 to 1250 mm/min. The results show that a sound joint could be obtained at a high speed of 1200 mm/min using DWMW. The weld zone (WZ) in the joint showed a dendritic structure of equiaxed grains, and in the fusion zone (FZ), the microstructure existed as a fine equiaxed crystal structure about 100 µm in thickness. In the WZ adjacent to the FZ, elongated columnar crystal structure distributed along to the interface, and coarse microstructure in the heat affected zone (HAZ) were found, showing a typical rolling texture. The main precipitates in the WZ were assumed to be Fe-enriched phases, and Mg- and Zn-enriched phases. Tensile fracture generally occurred in the WZ adjacent to the FZ with a decrease in ductility, and it was consistent with the results of the microstructure analysis and hardness profile. The mean ultimate tensile strength and elongation of specimens were 302 MPa and 4.5 %, respectively.
ISSN:0334-6455
2191-0324