8. New Technology Roots
Standard samples containing defects of known size, shape, and· location are requirements for the evaluation and calibration of NDE test equipment. Here we review the methods developed f~r producing such samples from selected metallic alloys and ceramics. In the work with metallic alloys, the method of diffusion bonding Ti-6Al-4V is presented in some detail and is illustrated for a large number of samples containing a variety of defects ranging from spherical cavities and inclusions, to prolate and oblate spheroids, to thin discs and simulated cracks. In the work with ceramics, the method of hot pressing of glasses with cavities and inclusions is illustrated for a variety of defects. The presentation demonstrates how these samples may be applied in a procedure for calibrating ultrasonic systems by employing a recently proposed characteristic equation for the system and a figure-of-merit for the transducers in analogy to the gain of a radar antenna.
Tittmann, Bernard R. and Paton, N. E., "New Ultrasonic Standards" (1978). Proceedings of the ARPA/AFML Review of Progress in Quantitative NDE, September 1976–June 1977. 51.