Time-of-Flight Diffraction Technique
The time-of-flight diffraction method is an ultrasonic tandem technique for precisely determining the vertical extent of internal flaws in weld samples. It measures time-of-flight differences of diffracted waves at crack tips.
Physical-Chemical Mechanism of Action
Time-of-Flight Diffraction (ToF-D) uses ultrasonic waves that are emitted by a transmitter and picked up by a receiver. The waves are diffracted at crack tips, resulting in different travel times. These differences are measured and processed to determine the depth and extent of internal defects.
Metallurgical Relevance & Risks in Welding
ToF-D is particularly useful for inspecting weld samples with dense cracks or internal defects because it allows high resolution and precision. Incorrect interpretation of the measurement data can lead to misdiagnosed defects, which poses risks to the safety of the component.
Workshop Practice & Action Instructions
To use the ToF-D procedure correctly, the following steps must be observed:
1. Set up the device: Make sure the ultrasonic transmitter and receiver are correctly aligned.
2. Prepare the sample: The samples must be clean and free of surface defects to achieve accurate results.
3. Perform the measurement: Send ultrasonic waves into the sample and record the travel times of the waves diffracted at crack tips.
4. Analyze the data: Use specialized software to process the measurement data and determine the depth and extent of internal defects.