Study of Strength and Corrosion Behavior on Aluminum A1050 and Copper C1100 Joints by Mechanical Steel Bolt, Blind Steel Rivet, and Resistance Spot Weld

Abstract

A1050 and C1100 are normally used as terminal tabs, they are connected either by mechanical joining, e.g. mechanical bolt, or rivet, or by welding, e.g. resistance spot welding. This study aimed to compare the mechanical bolt, blind rivet, and resistance spot welding methods by measuring important joining properties to support the process selection for joining terminal tabs in pouch cell batteries. T-peel-shaped were created and immersed in a 3.5 wt% NaCl electrolyte solution over different durations. Tensile tests were conducted to ascertain the maximum load-bearing capacity of the various joints. Furthermore, the electrical resistivities of the joints were measured using the 4-point probe technique. The corrosion rates of various joints were calculated from the corrosion current density (Icorr) measured from the Tafel polarization technique. ANOVA and Tukey’s test were used for analyst data comparison of the three joining techniques. Based on the mechanical properties, the mechanical joints by either steel bolt or steel rivet exhibited higher shear peeling strength than the resistance spot welding. The mechanical joining processes were simple with ease of maintenance, however, the use of steel components correlated with heightened corrosion rates and higher resistivity. Spot welding joints tended to produce low joining strength due to the brittleness of the welding spot. Nonetheless, the spot weld joints demonstrated minimal changes in resistivity following corrosion exposure as opposed to the mechanical joining counterparts.