Scanning Acoustic Microscopy in Materials Characterization

The scanning acoustic microscopy is a powerful tool for subsurface imaging and therefore fault detection in coated parts. In this paper several methods are established to reveal the imaging of hidden structures. First efforts were made to find out the information depth due to the various distances between lens and surface of the object. By means of a specially developed test specimen it was possible to estimate the penetration depth for monitoring structural details. The indepth analysis of layered composites is considered by the determination of the V(z)-characteristics. Furthermore the gain of image processing by means of Fourier transformed patterns and simultaneous filtering is shown by a typical example

Herausforderungen an FDM aus der Perspektive der qualitativen Sozialforschung

Nach einer kurzen Kontextbeschreibung durch die Forschungskoordinatorin des Instituts werden anhand zweier laufender Forschungsprojekte rechtliche, technische und fachwissenschaftliche Herausforderungen skizziert. Auf dieser Grundlage werden Ideen zu Vernetzungs-, Informations- und Schulungsbedarf formuliert

Qualifizierung von Pruefverfahren und Standards fuer die Duennschichttechnologie Abschlussbericht

Wear resistant coatings can be produced by different kind of PVD and CVD processes. User specified special requirements for different industrial applications ask for a stingent quality control. Therefore test methods must be standarized. In addition the quality of the tests must be guaranteed by standard samples. To analyse the test methods and for the development of standard samples steel samples were coated by PVD and CVD with hard coating (TiN_x, Ti_x(C_yN_z), (Ti_xAl_y)N_z). Chemical composition, hardness and adhesion were evaluated in round robins to verify the sample properties and examine the test methods. Well-known research institutes were involved to guarantee best valuation of the samples and the used analytical methods. As a result the comparability of methods for spectroscopical chemical analysis was improved by the standard samples. The composition of the standard samples could be evaluated by wet chemistry. So the calibration of the quantitative analysis was possible. Hardness measurements (Vickers method and load displacement indentation method) show a high hardness of the samples and small deviations in the round robins. Especially the load displacement indentation method is useful for hardness measurements at thin hard coatings, because systematic disturbances can be corrected to give best comparability. The scratch test for adhesion measurements is still far away from being standardized. In the round robins the measured critical loads were quite different. On the other hand for different coatings the tendency of the criticcal loads was comparable. The standard samples locate the remaining problems at the test machine and at the interpretation of coating damage. So they will give some impulses for the further development of the scratch test as an adhesion test method. (orig.)Available from TIB Hannover: F97B1747 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman