Non-microscopical methods for characterization of microstructures and properties of UFG metals

Michael J. Zehetbauer, Erhard Schafler, T. Ungár

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1 Citation (Scopus)

Abstract

The paper reports on non-microscopical methods which allow for close investigation of ultrafine-grained metals especially of those processed by different techniques of Severe Plastic Deformation. These are as follows: (i) X-ray Bragg profile analysis, (ii) electrical residual resistivity, (iii) annealing calorimetry, and (iv) positron annihilation spectro-scopy. The advantage of these methods lies in their integration/averaging over a certain sample volume so that they are often much closer to macroscopic physical properties than methods of microscopy; furthermore, the values of quantities obtained are more reliable because of strictly objective rules of determination. Typical quantities being relevant for ultra-fine grained materials are (a) grain size and grain size distribution, (b) long range internal stresses, (c) dislocation densities, and (d) concentration of vacancies and/or vacancy agglomerates. While quantities (a) and (b) are important for all classes of ultra-fine grained materials, those of (c) and (d) particularly occur with nanomaterials processed by severe plastic deformation also being responsible for their specific features such as ductility and the presence of non-equilibrium phases.

Original languageEnglish
Pages (from-to)290-298
Number of pages9
JournalZeitschrift fuer Metallkunde/Materials Research and Advanced Techniques
Volume98
Issue number4
Publication statusPublished - Apr 1 2007

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Keywords

  • Calorimetry
  • Re-sistometry
  • Severe Plastic Deformation
  • Ultra-fine-grained
  • X-ray diffraction

ASJC Scopus subject areas

  • Metals and Alloys

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