Air Coupled Ultrasonic Guided Waves for Non-Contact Cure Monitoring

A diagnostic tool for evaluating relative cure state in adhesives, coatings, and sealant systems would help increase production efficiency by avoiding unnecessary delays between applications while ensuring proper performance based on complete cure of the material system. Luna’s approach leverages ongoing developments of air-coupled ultrasonics and nonlinear acoustics to provide a solution with the potential for low-cost, high inspection efficiency, and ease of operation. The approach is based on monitoring guided wave velocity and attenuation whose equilibrium indicates complete cure. Luna’s line-based measurement approach provides greater flexibility based on inspection time and necessary spatial resolution compared with more common point-based measurements. The anticipated results of the Phase I effort include the development of a numerical model for optimizing sensitivity, proof-of-concept measurements on pertinent material systems deposited on Al 2024-T3 substrates in the based period and extended to composite substrates in the option. The transition to Phase II will include initial electronic design of a prototype device.