MICRORADIOGRAPHIC DETECTION OF CORROSION PITTING

A microradiographic characterization of corrosion pitting in 2024-T3 a luminum alloy is reported. Using projection magnification the radiogra phic parameters were optimized to reduce system unsharpness. Contrast sensitivity of less than 2 percent and pit size detection of less than 10 mu m (0.0004 in.) were achieved using the microradiographic system developed. Reduction of scattered radiation and improvement of signal -to-noise ratio and contrast are additional advantages of the use of p rojection magnification in microradiography. The microradiographic ima ges of corrosion were further optically magnified to enhance detectabi lity. Comparison of images taken by micro and conventional radiography shows significant advantages in the microradiographic method. Using s amples with artificial pits calibration curves were established for co rrosion-pitting depth determination in aluminum.