Pulse-Echo Ultrasonic Testing
The pulse-echo ultrasonic method uses high-frequency sound waves to detect internal and external flaws in metals. It measures the travel times and amplitudes of reflected echoes for precise defect localization.
Physical-Chemical Mechanism of Action
High-frequency sound waves are introduced into the material. These waves hit interfaces within the material and are reflected. The time it takes for the waves to return to the receiver (travel time) and their strength (amplitude) are measured.
Metallurgical Relevance & Risks in Welding
This method allows precise detection of volume flaws such as cracks, inclusions, or corrosion spots, as well as surface flaws like damage or coatings. Incorrect settings can lead to inaccurate results and may overlook critical flaws.
Workshop Practice & Action Instructions
Use a high-quality ultrasonic device with high frequency (e.g., 5 MHz for thin metals, 1 MHz for thick metals). Ensure that the couplant provides good sound transmission and that the specimen is clean. Measure travel times and amplitudes carefully and compare results with reference values. If defects are suspected, repeat the test at different locations.