Ultrasonic testing using electromagnetic acoustic transducers
Ultrasonic testing with electromagnetically excited ultrasonic waves uses magnetostriction to generate waves directly in the metal. This eliminates the need for a coupling medium.
Physicochemical Mechanism of Action
Electromagnetic excitation of ultrasonic waves is based on magnetostriction, where magnetic fields influence the mechanical properties of the metal. This generates the ultrasonic waves directly in the material.
Metallurgical Relevance & Welding Risks
This method allows precise, non-contact testing of components, especially in complex or hard-to-reach areas. It can find the smallest shrinkage cavities or cracks that conventional methods would miss. Risk: wrong settings can falsify the results and cause errors.
Workshop Practice & Instructions
For a successful ultrasonic test, these steps matter:
1. Set up the device: Match the magnetostriction frequency and amplitude to the metal being tested.
2. Prepare the part: No couplant needed – the electromagnetic field generates the waves directly.
3. Run the test: Move the ultrasonic device over the part and evaluate the reflections from cavities or cracks.
4. Evaluate the results: Check the data for quality and interpret it to detect defects.