Characterisation of ultrasonic welding of al-al with dry, methanol and acetone medium between the weldments

Abstract

The ultrasonic welding method is a solution to join alloys that have high thermal conductivity. In this study, the ultrasonic welding method was applied on Al 6061 T6 aluminium alloy and the effects of different lubricants at the interface were examined. A feasibility test was performed initially by varying parameters like pressure, amplitude, delay time, weld time, hold time, power, force, energy and stroke while keeping other parameters constant. The results of the test helped in setting up the actual parameters of the study. A comparative study amongst two different interface lubricants namely methanol and acetone was performed and compared with dry welding conditions. The lubricants were applied at the faying surface to better understand the effects of friction and relative motion between the foils. The highest tensile strength was observed in case of methanol (151.15 MPa), followed by acetone (145.26 MPa) and dry condition (98.05 MPa). In the case of methanol, lubrication increased the inter-metallic temperature leading to deformation at the surface allowing proper mixing of metals and thus, enhancing strength. Next, a microstructure analysis was performed indicating plastic deformation and grain refinement more in case of lubricants. Lastly, a fractographic image analysis was done to observe the various fractures visualized during tensile testing.