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Title: Mechanical and structural characterizations of gamma- and alpha-alumina nanofibers

We investigate the applicability of alumina nanofibers as a potential reinforcement material in ceramic matrix compounds by comparing the mechanical properties of individual nanofibers before and after annealing at 1400 °C. Mechanical testing is performed inside a scanning electron microscope (SEM), which enables observation in real time of the deformation and fracture of the fibers under loading, thereby providing a close-up inspection of the freshly fractured area in vacuum. Improvement of both the Young's modulus and the breaking strength for annealed nanofibers is demonstrated. Mechanical testing is supplemented with the structural characterization of the fibers before and after annealing using SEM, transmission electron microscopy and X-ray diffraction methods. - Highlights: • Mechanical properties of individual alumina nanofibers were measured using in situ SEM cantilevered beam bending technique. • Improvement of mechanical properties of the alumina fibers after annealing at 1400 °C is demonstrated. • Formation of branched structures is demonstrated and their mechanical properties are studied. • XRD and electron microscopy were used for structural characterization of untreated and annealed nanofibers.
Authors:
;  [1] ;  [2] ;  [1] ;  [3] ; ; ;  [1] ;  [1] ;  [4] ;  [1]
  1. Institute of Physics, University of Tartu, Ravila 14c, 50412 Tartu (Estonia)
  2. Institute of Solid State Physics, University of Latvia, Kengaraga 8, LV-1063 Riga (Latvia)
  3. (Russian Federation)
  4. (Estonia)
Publication Date:
OSTI Identifier:
22476158
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 107; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; ALUMINIUM OXIDES; ANNEALING; CERAMICS; FIBERS; INSPECTION; MICROSTRUCTURE; NANOFIBERS; SCANNING ELECTRON MICROSCOPY; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION