Zerstörungsfreie Ermittlung des Werkstoffzustandes

Materials properties depend upon the structure of materials. Several groups of properties can be correlated to typical structure dimensions. For example mechanical properties can be correlated to the microstructure of the material and to the crystal lattice defects for instance. Non-destructive methods normally do not detect the material properties directly. For example mechanical properties are defined in destructive experiments. Most of NDT-methods are sensitive to material structure. Methods are available for instance for structure dimensions of the order micrometers and millimeters. There is a need for methods which are able to give an information about crystal lattice defects. This job can be done either by magnetic or acoustic methods (for example the absorption of ultra-sound). On the other hand methods from solid state physics, for example positron annihilation, are now qualified for an application in NDT. A brief review of methods available is given in the paper.