A Novel Non-Destructive Sensing Technology for On-Site Corrosion Failure Evaluation of Coatings

Abstract

The quality of coating and the resulting rate of corrosion of the underlying metal substrate can be measured by a variety of corrosion measurements (Tafel, electrochemical impedance spectroscopy) by using standard laboratory electrochemical cells. However, there is always a need of low cost, portable, and non-destructive electrochemical cells, which can be used on-site field for condition monitoring of large structures for example bridges and large infrastructures, complex operating systems as aircrafts, precision machines, petrochemical processes, automotive, and locomotives. This research has developed state of the art cells fabricated by using a special magnetic aluminum compound (AlnXn), which is highly electrically conductive and corrosion resistive. The research has commissioned for deploying this novel sensing technology for micro-defects detection, corrosion rate measurement, and condition assessment of the defected coatings. Tafel measurement facilitated by these non-destructive cells is used to detect micro-defects and corrosion rate measurement while electrochemical impedance spectroscopy measurement is facilitated to measure the coating condition. This technology has been successfully tested and commissioned on automotive, hazardous compartments with polymeric coatings and bridges to assess their coating condition in terms of their structural integrity. Post design testing involved the installation of these cells, running diagnostics, data acquisition, and macrographs to predict structural defects and the resulting corrosion rate. This technology enables the design process to incorporate operational conditions and fully realize more durable and reliable solutions to be applied to high-value large structures and complex interacting systems. Current developments in corrosion condition monitoring especially cost effective and non-destructive techniques to assess structural integrity beneath nonconductive and polymeric coating were long awaited. This reported development will revolutionize durability and reliability assessment techniques to enhance safety and mitigate catastrophic failures for cost savings and avoiding fatal accidents.