Instrumented Test Coupons and Monitoring System for Improved Materials Performance Evaluations

ABSTRACT: The annual cost of corrosion for Air Force aircraft and missiles is estimated to $5.4 billion with corrosion accounting for 32.2% of the maintenance budget. Military performance requirements for materials qualification often rely on pass/fail measurements of flat panels exposed in continuous salt fog tests. It is well know that corrosion protection systems and alloys may fail due to other corrosion processes associated with localized corrosion, galvanic couples, and mechanical loading which may not be evaluated using current practices. Although advances have been made in the development of more representative accelerated corrosion tests, similar advancements in the test coupon design and instrumentation have not been realized. Luna is developing a smart test coupon (STC) that incorporates multimodal measurements using affordable, advanced sensors, and monitoring techniques to improve materials evaluation in accelerated laboratory corrosion and service environment testing. The STC system continuously monitors environmental parameters, corrosion, coating performance, and material residual strength throughout a corrosion test. The STC system will support coating and materials technology assessment and demonstration. BENEFIT: The smart test coupon (STC) technology offers a unique capability that presently does not exist. The STC technology enhances existing coupon test methods by adding existing and novel corrosion sensing technologies to achieve a powerful investigative tool. The ability to assess the impact of coatings and inhibitors on the kinetics and cumulative damage of a wide array of corrosion processes will improve both development and qualification activities. This will be important to researchers and users of industrial finishes for aerospace, automotive, marine, and infrastructure applications. Significant societal benefits will be realized through more rapid and safe adoption of environmentally compliant coating systems. The primary market for the system will be research organizations and test laboratories that perform materials development and qualification testing. The system will also be useful for development of accelerated test methods, surveying usage environments, and validating sensor technologies for in-service monitoring.