Influence of shielding gas on the mechanical and metallurgical properties of DP-GMA-welded 5083-H321 aluminum alloy

• Published in: International journal of minerals, metallurgy and materials Vol. 23; no. 12; pp. 1416 - 1426
• Main Authors: Koushki, Amin Reza, Goodarzi, Massoud, Paidar, Moslem
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.12.2016; Springer Nature B.V; Department of Metalurgy and Materials Engineering, Iran University of Science and technology, Tehran, Iran%Department of Materials Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
• Subjects: Aluminum; Aluminum alloys; Aluminum base alloys; Argon; Bend strength; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Corrosion and Coatings; Gas composition; Gas metal arc welding; Glass; GMA; Intermetallic compounds; Materials Science; Metallic Materials; Natural Materials; Nitrogen; Oxide coatings; Oxygen; Shielding; Surfaces and Interfaces; Tensile strength; Thin Films; Tribology; Weld metal; Welded joints; X-ray spectroscopy; X射线光谱分析; 保护气体; 焊接性能; 表面氧化膜; 金属间化合物; 铝合金; metallurgical properties; gas metal arc welding; shielding gas; aluminum alloys; mechanical properties; aluminumalloys
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-016-1365-2

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.