Investigation of Connection Performance and Failure Mechanisms of Sealed Crimp Connectors for Copper-Clad Aluminum Wires

This study investigates the sealing performance and reliability of sealed crimp connectors for copper-clad aluminum (CCA) wires, a promising lightweight solution for aerospace applications. Finite element analysis was used to simulate the crimping process, revealing critical stress concentrations at key indentation sites of the silver casing. Two groups of samples, differentiated by optimal and insufficient crimping depths, were subjected to accelerated environmental and mechanical tests. Comprehensive evaluations, including tensile strength measurements, contact resistance assessments, and advanced microstructural characterizations using SEM and FIB imaging, demonstrated distinct performance differences between the groups. The optimally crimped samples exhibited robust sealing at critical interfaces and maintained stable electrical performance, whereas the insufficiently crimped samples showed localized leakage, interfacial corrosion, and gap formation at the sealing region. Furthermore, prolonged environmental exposure induced significant microstructural changes at the copper–aluminum interface and within the silver casing, contributing to increased contact resistance and compromised sealing integrity. These findings underscore the importance of precise crimping process control to mitigate degradation mechanisms and enhance the long-term reliability of CCA connectors in harsh aerospace environments.