Experimental investigation on ultrasonic spot welding of aluminum-cupronickel sheets under different parametric conditions.

Ultrasonic spot welding (USW) is a solid-state joining process which is preferably adopted in the joining of lithium-ion battery tabs for hybrid electric vehicles. It has several benefits over traditional fusion welding techniques like shorter weld time, no formation of the heat-affected zone (HAZ), less energy consumption and lower operating cost. The present research work explores the effect of various welding factors like weld time, weld pressure and vibration amplitude on the tensile shear strength for joining aluminum (AA1060) with cupronickel (UNS C71500) sheets. The results indicated that tensile shear load raised with grow in weld time and achieved the peak value of 809 N. The various types of weld qualities were also identified such as 'under weld', 'good weld' and 'over weld' based upon the nature of bond formation at several weld parametric conditions. The detailed microstructural investigation on the welding region revealed the bonding mechanism with the mechanical interlocking feature and the correlation between the weld strength and the bond density was also established. [ABSTRACT FROM AUTHOR]