What type of defects can ultrasonic testing typically detect?

Ultrasonic testing (UT) is a nondestructive testing method that is particularly effective for detecting subsurface defects, voids, and inclusions. The fundamental principle behind ultrasonic testing involves sending high-frequency sound waves into the material being tested; when these waves encounter a discontinuity such as a defect, they are reflected back to the transducer. This ability allows ultrasonic testing to identify flaws that are not visible on the surface, making it suitable for detecting internal issues within a variety of materials.

Subsurface defects may include cracks, cavities, or inclusions that might not be accessible through visual inspection or other testing methods. The capability to assess these hidden imperfections is one of the key advantages of ultrasonic testing, especially in applications where material integrity is crucial, such as in weld inspections, aerospace components, and pressure vessels.

In contrast, while ultrasonic testing can indicate corrosion, particularly if it leads to volumetric loss, its primary strength lies in identifying subsurface discontinuities. Therefore, the choice stating that UT can detect subsurface defects, voids, and inclusions accurately describes one of the main applications of this testing method.