Crystallization Mechanism of Amorphous Mullite and the Al 2 O 3 -SiO 2 Phase Diagram

  • PDF / 519,122 Bytes
  • 7 Pages / 612 x 792 pts (letter) Page_size
  • 110 Downloads / 257 Views

DOWNLOAD

REPORT


Crystallization Mechanism of Amorphous Mullite and the Al2O3-SiO2 Phase Diagram Waltraud M. Kriven Dept. of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801, U.S.A. ABSTRACT Recent progress in the crystallization of amorphous mullite (3Al2O3•2SiO2) and yttrium aluminate (Y3Al5O12, 5Al2O3•3Y2O3 or “YAG”) beads and fibers is reviewed. Studies were made by differential thermal analyses, (DTA, DSC), synchrotron X-ray diffraction and Rietveld profile fitting, HREM, EDS and SEM. Crystallization kinetics, activation energies and microstructures were determined, leading to temperature-time-transformation (T-T-T) curves. The crystallization of mullite from the solid state proceeds by formation of large-grained, pseudo-tetragonal mullite of composition 70 mol% Al2O3, which is highly strained and which contains

Data Loading...