Comparison of V groove design on mechanical performance and fracture behaviour in TIG welding of 5754-H111 aluminium alloy

Abstract

The aim of this study is to enhance the performance and effectiveness of welding 5mm thick plates with different groove designs and investigate their post-effects on material properties. Specifically, the study compares single V and double V butt joints of 5mm thick AA5754-H111 strain-hardened aluminium alloy using Tungsten Inert Gas (TIG) welding with ER5356 (Al-Mg) filler rod. Two types of weld grooves, single V groove and double V groove were utilized to examine the microstructure and character of the weld and to study the effect of heat distribution. The average Vickers hardness values were observed to be 78.2HV in the double V groove of weld zone compared to the 76.6HV in single V groove weld zone. The tensile strength of single V and double V groove were 210 and 207 MPA respectively. The results showed that the failure location of all weld samples was in the fusion zone (FZ) and exhibited brittle fracture. The microstructure of the weld fusion zone revealed the presence of porosity in various sizes, which was also observed in the fractography images of tensile failed samples. Moreover, the microstructure studies exhibited clear variations in the fusion, intersection, and heat-affected zones. The formation of particles was found to differ in the weld fusion zone at various locations due to changes in the V groove welding method.