Resistance spot welding of 6061-T6 aluminum: Failure loads and deformation

Highlights: → Failure loads in 6061-T6 aluminum resistance spot welded joints were investigated. → Force, displacement, and time were captured prior complete failure. → Nugget and microstructure characteristics were quantified. → We used laser beam profilometry and electron back scatter diffraction techniques. → Process sensitivity was captured and optimal welding conditions were established. -- Abstract: This study offers a novel research approach to compare weld quality for different welding conditions in order to achieve optimal end-product results. Using electron back scatter diffraction (EBSD) scanning, tensile testing, and laser beam profilometry (LBP) measurements along with optical microscopy (OM) images, failure loads and deformation of 6061-T6 aluminum alloy, resistance spot welded (RSW) joints were experimentally investigated. Three welding conditions, nugget and microstructure characteristics were quantified according to predefined process parameters. Quasi-static tensile tests were used to characterize the failure loads in specimens based upon these same process parameters. Profilometer results showed that the larger the applied welding current, the deeper the weld imprints. In addition, good correlation was obtained between the EBSD scans and the welding conditions. A strong dependency was found between the grain size and orientation and the welding parameters.