Evaluation of joint strength and interfacial characterization of aluminum 6061 alloy fabricated by electromagnetic joining technique

The present work aims to evaluate the strength of weldment of AA6061 alloys (similar metals) joined by electromagnetic joining technique (EMJ). The geometry of the flyer tube and target rods are analytically designed so that the welded samples should fail at the parent materials (base metals) or the joint interface in the pull-out test. Three failure zones are identified where joint samples might fail, and the samples are designed. These samples are joined using the energy level with three capacitor (3B) and four capacitor (4B) banks. Three case studies (case-1: target rod failure, case-2: flyer tube failure, and case-3: joint interface failure) are analyzed and experimentally validated. The interfacial strength was found to be depend on stand-off distance (SODs). The highest load bearing capacity of 24. 83 kN was observed at 1.5 mm SOD as compared to 1 mm and 2.5 mm SODs at 24.3 kJ energy. Non-measureable process parameters are evaluated by numerical simulation method using LS-DYNA software. Microstructural analysis confirms formation of a wavy pattern, localized melting and compositional homogeneity along the interface of 10–80 µm. No intermetallic phase was observed at the interface. The excellent interfacial bonding strength was attributed to the absence of transition zone. Hardness measurement confirms the presence of finer grains along the interface formed by the severe plastic deformation.