Advanced techniques for aerospace materials testing

Three non-destructive tests are described for the characterization of large thick sheets of substrate materials, such as Shuttle tile. The tests are real-time X-ray imaging, automated millimeter-wave testing, and high-temperature testing using a high-power CO/sub 2/ laser. These methods allow substrate evaluation before use in the manufacture of electronic or electrooptic components. Besides defining the electrical properties, the tests detect perturbations in the substrate smaller than 0.03 in. The electrical performance can be measured at temperatures exceeding 3000 degrees F. >