EVALUATION OF NONDESTRUCTIVE TESTING TECHNIQUES OF DIFFUSION COATINGS.
Final rept. Apr 66-Jul 67,
IIT RESEARCH INST CHICAGO IL
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Three novel nondestructive testing methods of diffusion coatings were compared with other methods and checked against microscopic examination by subsequent sectioning of suspected defects. Methods used consisted of a beta backscatter, X-ray fluorescence and a magnetic eddy current technique. The eddy current technique showed that variations in coating thickness and local defects can be readily observed. This method can be used to scan large areas. Scanning speed was limited by the mechanical system used for scanning purposes. The beta backscatter method yielded low sensitivity and a rather low scanning speed of about 0.5 square centimeter per minute. X-ray fluorescence was carried out only at a few spots. Scanning rates of the order of 1 square centimeter per hour were obtained. Improved geometry can increase this by an order of magnitude but even such improvement is not likely to be competitive. Author
- Manufacturing and Industrial Engineering and Control of Production Systems