This Small Business Innovation Research Phase II project is to develop an improved non-destructive evaluation (NDE) system based on an ultrasensitive room-temperature magnetic sensor. The research is for a magnetoresistive eddy current instrument which will have unique capabilities including (1) low-frequency inspection through thick layers of aluminum or steel, (2) broad-band measurements from zero to several megahertz, and (3) large-area scanning-array imaging with high scan rates and high spatial resolution. During Phase I, the research instrument detected a small cavity on the back surface of an aluminum plate 4.9mm thick. The signal-to-noise ratio indicated that a crack roughly 1mm in diameter could be detected through 10mm of aluminum. During Phase II, research will be conducted to further enhance the instrument by establishing its sensitivity for detecting cracks and thickness loss, and by applying it to NDE problems to illustrate the potential applications in both aviation and maintenance of industrial infrastructure. This project activities will combine the firm's expertise in sensitive magnetic measurements with Kodak's improved sensor technology. In addition, Boeing and South West Research Institute will contribute to NDE experiments and the design of a practical NDE system. If successful, the improved NDE technology will reduce the cost and increase the effectiveness of inspecting aircraft and aging infrastructure. Representative applications include (1) detecting cracks and corrosion in thick and multilayer aircraft structures, (2) inspection of steel tubes in power-plant heat exchangers, (3) detecting corrosion under insulation, and (4) inspecting a reactor pressure vessel through its stainless-steel cladding.
