Heating rate dependence of anatase to rutile transformation
Commercial titania powders were calcined in order to investigate the influence of the heating history on the thermally stable phase (rutile). Temperatures from 620 to 700 °C and heating rates from 50 to 300 °C/h were used in order to evaluate their influence on the kinetics of transformation and mic...
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University of Novi Sad
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doaj-431986f2af1e4109b94a0e6bd085ffac2020-11-24T22:49:56ZengUniversity of Novi SadProcessing and Application of Ceramics1820-61312406-10342016-12-0110423524110.2298/PAC1604235GHeating rate dependence of anatase to rutile transformationPietro Galizia0Giovanni Maizza1Carmen Galassi2CNR-ISTEC National Research Council of Italy - Institute of Science and Technology for Ceramics, Faenza (RA), 48018 Italy; Polytechnic of Turin, Department of Applied Science and Technology, Torino (TO), 10129 ItalyPolytechnic of Turin, Department of Applied Science and Technology, Torino (TO), 10129 ItalyCNR-ISTEC National Research Council of Italy - Institute of Science and Technology for Ceramics, Faenza (RA), 48018 ItalyCommercial titania powders were calcined in order to investigate the influence of the heating history on the thermally stable phase (rutile). Temperatures from 620 to 700 °C and heating rates from 50 to 300 °C/h were used in order to evaluate their influence on the kinetics of transformation and microstructure evolution. The quantitative analysis of anatase-rutile mixtures based on X-ray diffraction intensities was performed. The results were plotted as cumulative transformation rate vs. cumulative coarsening rate in order to address the heating history of the anatase to rutile transformation. As the main result it was found that the amount of anatase transformed into rutile increases with increasing heating rate at fixed soaking time and temperature of calcination. Through linear extrapolation of experimental data obtained from the calcined commercial titania Degussa P25, it was found that 83 nm for the rutile crystallite size is the lowest limit needed for getting 100% of rutile powders. A substantial improvement in the anatase to rutile kinetic transformation was achieved after pressing the starting powders in order to exploit the interface nucleation.http://www.tf.uns.ac.rs/publikacije/PAC/pdf/PAC%2034%2005.pdftitaniacalcinationX-ray diffractionpolymorphic phase transformation kinetic |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Pietro Galizia Giovanni Maizza Carmen Galassi |
spellingShingle |
Pietro Galizia Giovanni Maizza Carmen Galassi Heating rate dependence of anatase to rutile transformation Processing and Application of Ceramics titania calcination X-ray diffraction polymorphic phase transformation kinetic |
author_facet |
Pietro Galizia Giovanni Maizza Carmen Galassi |
author_sort |
Pietro Galizia |
title |
Heating rate dependence of anatase to rutile transformation |
title_short |
Heating rate dependence of anatase to rutile transformation |
title_full |
Heating rate dependence of anatase to rutile transformation |
title_fullStr |
Heating rate dependence of anatase to rutile transformation |
title_full_unstemmed |
Heating rate dependence of anatase to rutile transformation |
title_sort |
heating rate dependence of anatase to rutile transformation |
publisher |
University of Novi Sad |
series |
Processing and Application of Ceramics |
issn |
1820-6131 2406-1034 |
publishDate |
2016-12-01 |
description |
Commercial titania powders were calcined in order to investigate the influence of the heating history on the thermally stable phase (rutile). Temperatures from 620 to 700 °C and heating rates from 50 to 300 °C/h were used in order to evaluate their influence on the kinetics of transformation and microstructure evolution. The quantitative analysis of anatase-rutile mixtures based on X-ray diffraction intensities was performed. The results were plotted as cumulative transformation rate vs. cumulative coarsening rate in order to address the heating history of the anatase to rutile transformation. As the main result it was found that the amount of anatase transformed into rutile increases with increasing heating rate at fixed soaking time and temperature of calcination. Through linear extrapolation of experimental data obtained from the calcined commercial titania Degussa P25, it was found that 83 nm for the rutile crystallite size is the lowest limit needed for getting 100% of rutile powders. A substantial improvement in the anatase to rutile kinetic transformation was achieved after pressing the starting powders in order to exploit the interface nucleation. |
topic |
titania calcination X-ray diffraction polymorphic phase transformation kinetic |
url |
http://www.tf.uns.ac.rs/publikacije/PAC/pdf/PAC%2034%2005.pdf |
work_keys_str_mv |
AT pietrogalizia heatingratedependenceofanatasetorutiletransformation AT giovannimaizza heatingratedependenceofanatasetorutiletransformation AT carmengalassi heatingratedependenceofanatasetorutiletransformation |
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1725674315374919680 |