Investigating the Effect of Explosive Welding Variables on the Corrosion Behavior of Copper–Aluminum–Copper in the Salt Environment

Abstract

In this study, the corrosion behavior and microstructural transformations of 1000 series aluminum and copper tubes after an explosive welding process were investigated. Welding was performed with a fixed stand-off distance and various explosion thicknesses. Explosive welding was carried out using a consistent stand-off distance of 2 mm while varying the thickness of the explosive material of 60 mm (sample 1) and 80 mm (sample 2). The explosion velocity employed during the process was measured at 2504 m/s. Optical and electron microscopy images revealed that the thickness of the melting layer at the interface increases proportionally with the thickness of the explosive charge. Specifically, as the explosive thickness increased from 60 to 80 mm, the thickness of the melting layer increased as well. Also, the resuls of the potentiodynamic polarization test indicated a decrease in the corrosion potential from –670 mV (sample 1) to –665 mV (sample 2) as the explosive material thicknesses increased. At the same time, the corrosion current density rose from 52.34 µA/cm² (sample 1) to 78.32 μA/cm² (sample 2). An analysis of the Nyquist diagram for explosive welding samples revealed that the curve radius of sample 2 exceeded that of sample 1, suggesting a higher corrosion resistance in sample 1 compared to that in sample 2.