Apparent Activation Energy in Low Temperature Aging of Y-TZP Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 100-103
Author(s):  
Qi Fei Xie ◽  
Cheng Wang ◽  
Qing Feng Zan ◽  
Li Min Dong
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Apparent Activation Energy ◽  
Coordinate Systems ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Temperature Aging ◽  
Diffraction Patterns ◽  
Straight Lines ◽  
Temperature Aging

Apparent activation energy in low temperature aging of two kinds of Y-TZP ceramic was studied in this paper. The ceramics were processed into small pieces, and aging in 100°C, 110°C, 120°C, 130°C and 140°C respectively. The content of monoclinic phase was calculated by X-ray diffraction patterns and the microstructure was scanned by SEM. According to MAJ law and Arrhenius formation, straight lines were fitted in coordinate systems of ln (ln (1/(1 − f )))-ln t and ln b-1/T, and the kinetic parameters of low temperature aging of Y-TZP ceramic were calculated according to these lines. The results revealed that grain size significantly affected apparent activation energy of Y-TZP ceramics.

Application of X-Ray Diffraction Methods to the Identification of Natural and Synthetic Rubbers

1951 ◽  
Vol 24 (2) ◽  
pp. 355-365 ◽  
Author(s):  
S. Goldspiel ◽  
F. Bernstein
Keyword(s):  
Low Temperature ◽  
Geiger Counter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Temperature Aging ◽  
Stock Types ◽  
Diffraction Patterns ◽  
Rubber Stock ◽  
Temperature Aging ◽  
Natural And Synthetic

Abstract In this paper, x-ray diffraction patterns and data for rubber compounding ingredients are presented and applied to the identification of major crystalline ingredients in several basic rubber stock types. Methods for the identification of natural and synthetic elastomers by low temperature aging and (or) stretching, using film techniques, are described. The extension of such methods to the Geiger counter x-ray spectrometer is presented and discussed.

X-ray diffraction study of low temperature aging in U–5.8 wt.%Nb

2015 ◽  
Vol 456 ◽  
pp. 41-45 ◽  
Author(s):  
Yanzhi Zhang ◽  
Xiaolin Wang ◽  
Qinying Xu ◽  
Yufei Li
Keyword(s):  
Low Temperature ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Temperature Aging ◽  
Temperature Aging

scholarly journals Kinetics of carbothermic reduction of synthetic chromite

2014 ◽  
Vol 50 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Y. Wang ◽  
L. Wang ◽  
J. Yu ◽  
K.C. Chou
Keyword(s):  
Activation Energy ◽  
Apparent Activation Energy ◽  
Reduction Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chromite Ore ◽  
Current Reduction ◽  
Increasing Temperature ◽  
Isothermal Mode ◽  
Kinetics Of

In order to optimize the current reduction process of chromite, a good knowledge of reduction mechanism involved is required. The basic component in chromite ore is FeCr2O4, thus, kinetic investigation of synthetic FeCr2O4 with different amount of carbon were carried out in the temperature range of 1473K to 1673K under both isothermal and non-isothermal mode. The iron can be easily reduced compared with chromium. And higher reduction degree of chromite can be achieved by increasing temperature and carbon content. With the supporting of X-ray Diffraction and Scanning Electron Microscope methods, the formation of metallic products followed the sequence: Fe-C alloy, (Fe,Cr)7C3and Fe-Cr-C alloy. Kinetics analysis showed that the first stage was controlled by nucleation with an apparent activation energy of 120kJ/mol, while the chromium reduction was controlled by crystallochemical transformation with an apparent activation energy of 288kJ/mol.

Low Temperature Preparation of y‐bA‐cU‐0 Films by Omcvd

1989 ◽  
Vol 169 ◽  
Author(s):  
Taiji Tsuruoka ◽  
Ryodo Kawasaki ◽  
Hitoshi Abe ◽  
Susumu Shibata
Keyword(s):  
Low Temperature ◽  
Deposition Rate ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
X Ray ◽  
Low Temperature Preparation ◽  
Zero Resistance ◽  
Diffraction Patterns ◽  
Temperature Preparation

AbstractBy using N2O for oxygen source, Y‐Ba‐Cu‐O films prepared at 650” C on the SrTiO3 substrates showed zero resistance at 79K. The deposition rate of Y‐Ba‐Cu‐0 films on MgO(l00) substrates by using N2O gas was nearly half of that using 02 gas. X‐ray diffraction patterns of Y‐Ba‐Cu‐0 films grown on SrTiO3(100) and MgO(l00) substrates indicate c‐axis orientation.

Preparation and Properties of Rectorite/Epoxy Nanocomposites

2014 ◽  
Vol 875-877 ◽  
pp. 145-149
Author(s):  
Ting Ting Zeng ◽  
Lai Chen ◽  
Da Peng Li ◽  
Jin Liang Sun ◽  
Ze Zhou ◽  
...  
Keyword(s):  
Activation Energy ◽  
Apparent Activation Energy ◽  
Organic Cation ◽  
Epoxy Composites ◽  
X Ray Diffraction ◽  
Epoxy Nanocomposites ◽  
X Ray ◽  
Working Temperature ◽  
Curing Agents ◽  
Exchange Agent

The Org-rectorite, which was used as a filler in the Rectorite/Epoxy nanocomposites, was prepared by the intercalation and exfoliation of rectorite with dodecyl-bis (2-hydroxyethyl)-methylazanium chloride as the organic cation exchange agent. The two curing agents methyl hexahydrophthalic anhydride (MHHPA) and m-phenylenediamine were employed at working temperature ranging from 70 °C to 190 °C. The samples were characterized by Fourier Transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and differential scanning calorimeter (DSC) analysis. The results show that the d001 (55.9 Å) of Rectorite/Epoxy composites cured with MHHPA at 70 °C was larger than the Org-rectorite (28.7 Å), and the Org-rectorite was exfoliated at 90 °C working temperature. While the d001 of Rectorite/Epoxy composites cured with m-phenylenediamine at 70 °C and 90 °C were 40.9 Å and 42.1 Å , and were exfoliated at 140 °C. The apparent activation energy (Ea) of Rectorite/Epoxy composites cured with MHHPA and m-phenylenediamine were obtained to be 74.85 and 59.15 KJ/mol, respectively. The higher apparent activation energy (Ea) of MHHPA systems may be responsible for the lower exfoliation temperature.

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