Nondestructive Evaluation Techniques for Silicon Carbide Heat-Exchanger Tubing

The adequacy of various nondestructive evaluation (NDE) techniques for inspecting silicon carbide heat-exchanger tubing is discussed. These methods include conventional ultrasonics, acoustic microscopy, conventional and dye-enhanced radiography, holographic interferometry and infrared scanning techniques. On the basis of current test results and an examination of the discussions in available literature, these techniques were compared with respect to (a) effectiveness in detecting cracks, pitting, inclusions, and voids, (b) effectiveness in characterizing detected flaws, (c) adaptability to tube geometry, (d) adaptability to in-service inspection, (e) reliability, and (f) extent of development required for commercialization