ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
TiO2/(O′+β′)-Sialon multiphase ceramics with different phase composition of TiO2 wereprepared by pressureless sintering under high-purity N2 atmosphere with (O′+β′)-Sialon powder and nanoTiO2 (anatase) powder as raw materials, Yb2O3 or Tb2O3 as additive. For each sample, the weightpercentage of anatase in TiO2 was calculated from XRD data and the kinetics of anatase-rutiletransformation was investigated, wherein the emphasis was placed on the influence of Yb2O3 and Tb2O3.The results indicate that the added Tb2O3 and Yb2O3 serve the significant function of inhibition andpromotion on the phase transformation, and the effects are enhanced and attenuated with increasingadditive content, respectively. For the sample without additive, the transformation process followsapparent first-order kinetic model. The addition of Yb2O3 or Tb2O3 results in completely differenttransformation kinetic law. For the samples with Yb2O3 added, the transformation is an apparentsecond-order reaction, whereas a unique kinetic model, CA=kt1/2+C, is valid for the samples containingTb2O3. In the two cases, the effect of the additive content on the transformation can be perfectly reflectedby the apparent rate constant
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/53/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.336-338.2318.pdf
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