Time-Of-Flight Diffraction Method
Ultrasonic time-of-flight diffraction (TOFD) is a precise testing method that diffracts waves at cracks and determines flaw height. It is suitable for detailed volumetric weld inspections.
Physico-chemical mechanism of action
Time-of-flight diffraction (TOFD) uses high-frequency ultrasonic waves that diffract at the tips of cracks or flaws. The diffracted waves are captured by a receiver and analyzed.
Metallurgical relevance & risks in welding
This technique allows accurate determination of flaw height and depth in weld areas. It helps detect microstructural defects and hidden cracks that other inspection methods might overlook. Incorrect interpretation or technical issues can lead to inaccurate results.
Workshop practice & action instructions
Use TOFD for detailed weld inspection, especially in complex components. Make sure the ultrasonic equipment is properly calibrated and the wave direction is optimally set. Inspection time should be at least 10 seconds per cm of weld to achieve accurate results.