This Small Business Innovation Research Phase I project will demonstrate a new, advanced, rapid nondestructive inspection technique for use on composite materials during manufacturing and in-service inspection. Composite materials are rapidly becoming strong, lightweight substitutes for a great variety of traditional metallic structural components. However, composites are often difficult to inspect for discontinuities or impact damage due to their high electrical resistivity and/or high ultrasonic attenuation. It is proposed that composites be tagged during manufacturing with trace quantities of magnetic powders in the binding matrix and/or with ferromagnetic or electrically conducting wire screens among the fiber layers - such screens are already commonly employed in existing aerospace composites for deicing heaters and lightning protection. It is further proposed that an electrically noncontacting magneto-optic/eddy current imaging system, the MOI, then be used to form rapidly scanned, real-time images of voids and impact damage deliberately introduced into these materials. With an appropriate choice of tagging materials, composite samples and controlled experiments involving the MOI and SQUID magnetometers, Physical Research, Inc., will demonstrate the feasibility of rapidly imaging and detecting otherwise hidden discontinuities and impact damage.
