Effects of the Number of Welding Passes on Microstructure and Properties of 2219-C10S Aluminum Alloy TIG-Welded Joints

Effects of the number of welding passes on microstructure and properties of 2219-C10S aluminum alloy tungsten inert gas (TIG) welded joints were analyzed in detail. The first capping weld had a solid solution effect on the backing weld. The second capping weld had a solid solution effect on the backing weld close to the capping weld and had an aging effect on the backing weld away from the capping weld. The sizes and quantities of the second phases in partially melted zone (PMZ) and over-aged zone (OAZ) increased slightly with the number of welding passes increased. The hardness of OAZ decreased slightly and its width increased slightly. The larger strain distribution range before tensile fractured of the joints was narrower and the range of plastic deformation of the joints was not significantly improved. The eutectic structure and theta phase at weld toes were not conducive to the tensile properties of joints. The tensile properties of double-pass welded joints were relatively ideal.

Automated summary

The number of welding passes has an impact on the microstructure and properties of 2219-C10S aluminum alloy tungsten inert gas (TIG) welded joints. Increased welding passes lead to slightly larger sizes and quantities of second phases, while also causing a slight decrease in hardness and increase in width of certain zones. However, double-pass welded joints generally exhibit relatively ideal tensile properties.