The response of heat-treatable filler on non-heat-treatable aluminum alloy substrate against age hardening cycle for intelligent development of surface welded joints using TIG welding process

A more realistic approach is handpicked to scrutinize the weld strength of surface joints using tungsten inert gas welding for repair work. Due to the increased application of non-heat-treatable aluminum alloy (AA5182) in automobile structures, tensile weld strength is tested against heat-treatable filler (AA6061) at three age hardening temperatures (i.e., 170 °C, 200 °C, 230 °C) and times (i.e., 4, 5, 6 h). A convincing increase in peak load value is spotted by increasing the temperature and time, the highest value of 14.06 kN is witnessed at 170 °C and 6 h along with 30.42% improvement in joint strength in contrast to without age hardening state. Comparable high peak load (i.e., 13.89 kN and 13.87 kN) values were also obtained for 200 °C and 230 °C at 4 h but afterward depicted a declining trend at 5 and 6 h. An important macrocharacteristic examination of an inside fused region has represented an area of 42.71% which has comparatively shown a negligible difference of percentage with other specimens. From the regional microstructure perspective, two evidential mechanisms were involved in the strengthening, which includes the adjusted network of grain boundary morphology and the precipitation of Mg2Si which upsurge the growth during age hardening. In addition, the apprehension behind the declining behavior at high temperature is explicatively exemplified from scanning electron microscope micrographs which clinch the coalescence of small voids and the evaporation of Mg from surface as an ultimate reason.