Unconventional NDT methods based on elastic waves
At the Fraunhofer IKTS site in Dresden-Klotzsche our focus is on developing advanced non-destructive testing solutions for ceramics and many other materials. We are constantly working on new solutions. We would like to present some of these to you in our new NDT4INDUSTRY online seminar series.
Online seminar – Unconventional NDT methods based on elastic waves on November 24, 2021, 3:00 p.m. CET with Dr. Bernd Köhler (NDT lab)
Issues like (1) finding inclined cracks (2) material characterization by Rayleigh wave velocity measurements, (3) grain structure mapping or (4) finding defects in objects with a very uneven surface cannot not be solved with standard ultrasonic methods, where a transducer scans objects in direct contact with the surface or in a water bath.
Dr. Bernd Köhler talks about non-standard ultrasonic testing, that researchers at Fraunhofer IKTS found for such cases by replacing or modifying various parts of standard approaches. Examples are (1) replacing the transmitting transducer by a transducer focused on the sample surface for the mapping of inclined cracks, (2) using a goniometer arrangement for precise Rayleigh wave measurements and (3) replacing the receiver by a laser vibrometer for the grain structure mapping. Very strange might sound (4) usage of the immersion “frozen water” – that is ice! This approach named cryo-ultrasonics mitigates the sound diffraction which otherwise hinders finding all defects in parts with an uneven surface.
The aim of the seminar is not to present ready-made methods, but rather to engage conversation and to further develop the methods for concrete applications.