Each user knows about the existence of a medical device that allows you to safely conduct studies of human internal organs using ultrasound. It is especially widely used to monitor the development of the fetus in pregnant women. But that ultrasonic testing is used for flaw detection of welded seams of metals, not everyone knows.
How it works
The principle of devices for carrying out flaw detection of metals using ultrasound is based on the possibility of sound vibrations with a frequency of more than 20 KHz to propagate without problems in elastic (solid) media. Directly for research of seams, the frequency is from 0.5 to 10 MHz. At the same time, several diagnostic methods are distinguished, here are the main ones:
- Echo-impulse - the sound wave is directed to the weld with its further registration of the reflection from the existing defect.
- Shadow - special sound transducers are installed on the inside and outside of the seam. One of them directs sound vibrations, and the other, after they pass through the metal, catches. The absence (distortion) of the signal is a sign of a poor connection.
- Mirror-shadow - signal converters are installed on one side of the investigated seam. Loss of signal is a sign of a defect.
The most common and frequently used method in practice is the pulse echo variant. The flaw detectors used for the inspections and the ultrasonic wave transducers included in their set, produced by the leading companies in this field, are available in a special laboratory. It provides a full range of services for any research of metals and alloys using this equipment on fairly favorable terms.
