Cracks, laminations, shrinkage cavities, bursts, flakes, pores, disbands, and other discontinuities that produce reflective interfaces are good candidates for Ultrasonic Inspection. Inclusions and other inhomogeneities can also be detected by causing partial reflection or scattering of the ultrasonic waves or by producing some other detectable effect on the ultrasonic waves.
Ultrasonic inspection is one of the most widely used methods of nondestructive inspection. Its primary application in the inspection of metals is the detection and characterization of internal / external flaws, define bond characteristics, and measure the thickness and extent of corrosion.
Some notable properties of Ultrasonic Inspection:
- Manual operation requires careful attention by experienced technicians
- Extensive technical knowledge is required for development of procedures
- Parts that are rough, irregular in shape, very small, or thin are difficult to inspect.
- Discontinuities that are present in a shallow layer beneath the surface are difficult to inspect.
- Reference standards are needed for both calibrating the instrument and for characterizing flaws