Evaluation of Aluminum Corrosion and Composite Heat Damage Using Magnetic Resonance NDE

Abstract

INTRODUCTIONMagnetic resonance nondestructive evaluation (NDE) methods are being used successfully in the medical, biological and petroleum industries due to their sensitivity to human tissue and other fluid materials. Application to NDE of solid materials, such as those utilized in the aerospace industry, has been limited due to the lower resolution and increased bandwidth of the measurements. With the recent development of measurement techniques and instrumentation appropriate for the NDE of solids, the sensitivity of NMR applied to solid materials has improved; as a result, increasing attention is now being given to the technique's ability to evaluate aerospace materials and structures. During this program [1], magnetic resonance techniques were found to be useful for evaluation of corrosion in aluminum and heat damage in composite materials. In a previous study [2], corrosion and heat damage were shown to be detectable using nuclear magnetic resonance (NMR). In this program, these phenomena were evaluated in greater detail using additional NMR parameters and the electron spin resonance (ESR) technique. BACKGROUND