Mechanical Behavior of Ultrasonic Spot Welded Aluminum to Cupro-Nickel Sheets for Battery Tabs

Abstract

Ultrasonic metal welding process has received noticeable attention throughout the last few years because of their proper application in comparison to the conventional fusion welding process. Fusion welding of dissimilar metals like copper and nickel, copper and aluminum alloy is always a difficult task due to the different physical, chemical, thermal properties, poor control of grain size and it has a deleterious effect on mechanical properties. Automotive industries have been widely accepted the ultrasonic metal welding process for assembling lithium-ion battery tabs. The aim of this current work is to investigate the weldability of two dissimilar metals namely aluminum (AA1060) and cupronickel (UNS C71500) sheets at various levels of welding time, vibration amplitudes and welding pressures with a fixed ultrasonic frequency of 20 kHz. The highest ultimate tensile shear strength test of joint achieved at highest vibration amplitude with moderate welding pressure and weld time. Weld quality determining characterization is introduced for the weld region to establish a relationship between physical attributes with the microstructural phenomenon.