Enhancement of Mechanical Properties of 6061/6082 Dissimilar Aluminium Alloys Through Ultrasonic-Assisted Cold Metal Transfer Welding

Nowadays, to enhance structural efficiency, ultrasonic vibrations are combined with other manufacturing processes such as welding. It gives considerable advantages in terms of improved mechanical properties, adequate surface strength, improved material flow and uniform grain growth, etc. Welding of 6061-T6 alloy with 6082-T6 aluminium alloys is carried out with dissimilar thickness. Ultrasonic-assisted cold metal transfer (U-CMT) welding is performed to fabricate the joints and improvements in mechanical properties and microstructural modifications are studied. The microstructural analysis is done with the assistance of an optical microscope (OM) and field emission scanning electron microscope (FESEM). The non-destructive technique (NDT) such as the radiography technique (RT) is used to test weld consistency. Results revealed that the weld bead dimensions are increased with the aid of ultrasonic vibrations for the same welding parameters. The tensile strength and microhardness are enhanced. Samples with ultrasonic vibration experience grain refining as compared to those without vibration samples. As compared with CMT, U-CMT is rich in Al-Si eutectic structure which is in globular form, reduces the porosity level.