Microstructure and mechanical properties of aluminum 5083 weldments by gas tungsten arc and gas metal arc welding

The mechanical properties and microstructural features of aluminum 5083 (Al5083) weldments processed by gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) are investigated. Weldments processed by both methods are mechanically softer than the parent material Al5083, and could be potential sites for plastic localization. It is revealed that Al5083 weldments processed by GTAW are mechanical more reliable than those by GMAW. The former bears higher strength, more ductility, and no apparent microstructure defects. Perceivable porosity in weldments by GMAW is found, which could account for the distinct mechanical properties between weldments processed by GTAW and GMAW. It is suggested that caution should be exercised when using GMAW for Al5083 in the high-speed-train industry where such light weight metal is broadly used.