2. Materials and Methods In this study, commercially pure 1 mm thick sheets of aluminum alloy EN AW 1050 (Al) and copper alloy EN CW 008A (Cu) both in half-hard condition were used to simulate the joining of battery tabs and bus bars. The selected mechanical properties of the base materials are listed in Table 1. A Herrmann HiS VARIO B (Herrmann Ultraschalltechnik GmbH & Co. KG, Karlsbad, Germany) welding system with a working frequency of 20 kHz was employed for this study.
