Influence of shielding gas on the mechanical and metallurgical properties of DP-GMA-welded 5083-H321 aluminum alloy
来源期刊：International Journal of Minerals Metallurgy and Materials2016年第12期
论文作者：Amin Reza Koushki Massoud Goodarzi Moslem Paidar
文章页码：1416 - 1426
摘 要：In the present research, 6-mm-thick 5083-H321 aluminum alloy was joined by the double-pulsed gas metal arc welding（DP-GMAW） process. The objective was to investigate the influence of the shielding gas composition on the microstructure and properties of GMA welds. A macrostructural study indicated that the addition of nitrogen and oxygen to the argon shielding gas resulted in better weld penetration. Furthermore, the tensile strength and bending strength of the welds were improved when oxygen and nitrogen（at concentrations as high as approximately 0.1vol%） were added to the shielding gas; however, these properties were adversely affected when the oxygen and nitrogen contents were increased further. This behavior was attributed to the formation of excessive brown and black oxide films on the bead surface, the formation of intermetallic compounds in the weld metal, and the formation of thicker oxide layers on the bead surface with increasing nitrogen and oxygen contents in the argon-based shielding gas. Analysis by energy-dispersive X-ray spectroscopy revealed that most of these compounds are nitrides or oxides.
Amin Reza Koushki1，Massoud Goodarzi1，Moslem Paidar2
1. Department of Metallurgy and Materials Engineering, Iran University of Science and technology2. Department of Materials Engineering, South Tehran Branch, Islamic Azad University
摘 要：In the present research, 6-mm-thick 5083-H321 aluminum alloy was joined by the double-pulsed gas metal arc welding（DP-GMAW） process. The objective was to investigate the influence of the shielding gas composition on the microstructure and properties of GMA welds. A macrostructural study indicated that the addition of nitrogen and oxygen to the argon shielding gas resulted in better weld penetration. Furthermore, the tensile strength and bending strength of the welds were improved when oxygen and nitrogen（at concentrations as high as approximately 0.1vol%） were added to the shielding gas; however, these properties were adversely affected when the oxygen and nitrogen contents were increased further. This behavior was attributed to the formation of excessive brown and black oxide films on the bead surface, the formation of intermetallic compounds in the weld metal, and the formation of thicker oxide layers on the bead surface with increasing nitrogen and oxygen contents in the argon-based shielding gas. Analysis by energy-dispersive X-ray spectroscopy revealed that most of these compounds are nitrides or oxides.
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