Cathodic delamination of modelled sea cable connector assemblies

摘要

Cathodic delamination failure is believed to be caused by the production of OH- at the polymer/metal interface via oxygen reduction reactions. In cable connector assemblies, the use of manufacturing processes and materials that are resistant to cathodic delamination failures is highly desirable. Also, there is a need for an accelerated testing regime for assessing the resistance of polymer-to-metal composites to cathodic delamination failures.Cable connector assemblies are employed in marine environments for structural terminations and circuit interconnection of electrical power and signal cabling systems. They are found on offshore sea beds, ROV’s, vessels and submarines and are prone to cathodic delamination related failures particularly when the cable assemblies are coupled to dissimilar metal appurtenances in seawater, e.g., zinc anodes.The resistance to cathodic delamination failures of selected metal substrates and polymeric materials used in the manufacture and sealing of cable connector assemblies have been investigated. Materials and methods of surface preparation by grit blasting to enhance polymer-to-metal adhesion, thus increasing the service life-time expectation of cable connector assemblies have been elucidated. Methods of accelerated testing of polymer/metal bond durability using salt spray test and the validation of the results in seawater immersion tests and potentiostatic experiments have been described. Also, a novel accelerated test chamber for cathodic delamination tests was designed and manufactured.Applied potential was observed to be the factor that had the most negative effect on test samples while silicon carbide grit was found to produce the most effective surface cleanliness and roughness combination required for durable polymer-to-metal bonds.