A Handheld Sensor for Amorphous Coating Integrity Evaluation

Under the DARPA sponsored Naval Advanced Amorphous Coating (NAAC) program, a novel, thermal sprayed amorphous metal coating has been developed. Such a coating has demonstrated superior mechanical and corrosion resistance properties. Although the coating is designed to be life-of-ship, the application and operational conditions may compromise the integrity of the coating. For example, the application parameters may not be appropriate to produce a fully amorphous structure. Overspray/unmelted particles can leave embedded oxide or particles within the coating, which will lead to coating surface corrosion. Even if the amorphous coating is successfully applied, the coating microstructure and the interconnect porosity may lead to a degraded coating/substrate interface, affecting the coating integrity. In this proposal, AlphaSense, Inc. (AI) and the Pennsylvania State University (PSU) detail the development of a novel noninvasive microwave sensor to evaluate the integrity of amorphous metal coating in real time. With our approach, the merits of the proposed sensor and its advantages over other techniques include: a) Rugged, handheld and low cost, b) Sensitive for defect detection, c) Capable of detecting defects in different forms, d) Noninvasive, e) Real- time analysis capability, and f) Easy and safe to the operators.