scholarly journals Grain Growth Kinetics of 0.65Ca0.61La0.26TiO3-0.35Sm(Mg0.5Ti0.5)O3 Dielectric Ceramic

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3905
Author(s):  
Jin Liu ◽  
Bingliang Liang ◽  
Jianjun Zhang ◽  
Wen He ◽  
Sheng Ouyang ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Prediction Accuracy ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Dielectric Ceramic ◽  
Nonlinear Regression Method ◽  
Grain Growth Kinetics ◽  
Grain Growth Behavior ◽  
Kinetics Of

The 0.65Ca0.61La0.26TiO3-0.35Sm(Mg0.5Ti0.5)O3[0.65CLT-0.35SMT] ceramic was prepared by the solid-state reaction method. The effects of sintering process on its microstructure and grain growth behavior were investigated. The Hillert model and a simplified Sellars model were established by linear regression, and the Sellars-Anelli model with a time index was established by using a nonlinear regression method. The results show that the grain size gradually increases with the increase of sintering temperature and holding time. Meanwhile, the sintering temperature has a more significant effect on the grain growth. The grain sizes of 0.65CLT-0.35SMT ceramic were predicted by the three models and compared with the experimentally measured grain size. The results indicate that for the 0.65CLT-0.35SMT ceramic, the Hillert model has the lowest prediction accuracy and the Sellars-Anelli model, the highest prediction accuracy. In this work, the Sellars-Anelli model can effectively predict the grain growth process of 0.65CLT-0.35SMT ceramic.

Effects of Solubility Limit and the Presence of Ultra-Fine Al6Fe on the Kinetics of Grain Growth in Dilute Al-Fe Alloys

2007 ◽  
Vol 550 ◽  
pp. 339-344 ◽  
Author(s):  
Shigeo Saimoto ◽  
Hai Ou Jin
Keyword(s):  
Grain Size ◽  
Cold Rolling ◽  
Grain Growth ◽  
Solubility Limit ◽  
Rolled Sheet ◽  
Migration Rates ◽  
Cold Rolled ◽  
Fe Alloys ◽  
Grain Growth Kinetics ◽  
Kinetics Of

A nominally pure Al slab was thermo-mechanically treated to result in a near random texture of 90 m grain size. Subsequent cold rolling with intermediate anneals at 230, 275, and 300°C reduced the Fe solute to near equilibrium compositions below 0.5 ppm atomic. The final cold rolled sheet continuously recrystallized; grain growth of this structure is reported. A grain-growth kinetics mapping was generated, correlating the parameters of Fe-in-Al solubility limit, Fe diffusivities in the grain boundaries and the Al lattice and the activation energies for migration rates.

Grain Growth Kinetics of Cobalt-Doped SnO2 by Varying Nb2O5 Content

2007 ◽  
Vol 534-536 ◽  
pp. 529-532 ◽  
Author(s):  
Dong Gyu Chang ◽  
Joon Hyung Lee ◽  
Jeong Joo Kim
Keyword(s):  
Grain Growth ◽  
Boundary Segregation ◽  
Growth Behavior ◽  
Grain Boundary Segregation ◽  
Growth Exponent ◽  
Space Charges ◽  
Grain Growth Kinetics ◽  
Grain Growth Behavior ◽  
Kinetics Of ◽  
Co Doped

SnO2 ceramics were co-doped with the aliovalent ions of CoO and Nb2O5 and the grain growth behavior of the SnO2 was investigated. When only CoO was doped, the grain growth exponent of SnO2 was 3. As the amount of Nb2O5 increased, the exponent changed from 3 to 2 when 0.505 mol% of Nb2O5 was added. The further addition of Nb2O5 changed the exponent from 2 to 3. When Nb2O5 content was 0.505 mol%, of which the grain growth exponent was 2, it is believed that an iso-electric point is formed without grain boundary segregation, since the respective space charges, generated by Nb5+ and Co3+ might compensate each other.

Relaxation and Grain Growth Behavior of Nanocrystalline Iron

1992 ◽  
Vol 272 ◽  
Author(s):  
J. C. Holzer ◽  
R. Birringer ◽  
J. Eckert ◽  
C.E. Krill ◽  
W.L. Johnson
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Peak Broadening ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Nanocrystalline Iron ◽  
Grain Growth Behavior ◽  
Kinetics Of

ABSTRACTNanocrystalline Fe has been prepared by inert gas condensation and ball milling. The kinetics of relaxation and grain growth are investigated by differential scanning calorimetry. The development of the microstructure is monitored by x-ray powder diffraction and transmission electron microscopy. Emphasis is placed on the differences observed for samples prepared by the two different techniques. We find that the kinetics of relaxation and grain growth are very sensitive to the sample preparation method. Samples with the same initial average grain size, as determined by the peak broadening in x-ray diffraction, show very different recovery behavior. The differences are discussed in terms of the estimated grain boundary energies and the initial grain size distribution obtained by the two preparation techniques.

Grain Growth Kinetics of (NdPr)2Fe14B Magnets

2014 ◽  
Vol 802 ◽  
pp. 540-545 ◽  
Author(s):  
Kaio Sérgio Torres de Souza ◽  
Célio de Jesus Marcelo ◽  
Daniel Rodrigues ◽  
José Adilson de Castro ◽  
Marcos Flavio de Campos
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Energy Product ◽  
Heat Treated ◽  
Coarsening Kinetics ◽  
Grain Growth Kinetics ◽  
Kinetics Of

Two different effects need to be considered in the sintering: (i) The densification should be maximum, to optimize the energy product BHmax and the remanence, however, (ii) the .grain size should be small, in order to maximize the coercivity. Grain growth takes place during the sintering step of the magnets, usually performed at the range 1000-1100°C. In this study, the grain growth kinetics is investigated. Samples of NdPrFeB magnets (proportion 3 Nd : 1 Pr) were heat treated at the temperature of 1050 °C, for times between 1 to 12 hours. The knowledge of the grain growth and coarsening kinetics allows extrapolation to other temperatures, and this information is helpful to maximize coercivity and remanence at the same time.

The Effect of Deformation and Reinforcement Particles on the Grain Growth Behavior of MoSi2

1993 ◽  
Vol 322 ◽  
Author(s):  
Ajoy Basu ◽  
Amit Ghosh
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
High Growth ◽  
Growth Behavior ◽  
Dislocation Creep ◽  
Grain Boundary Mobility ◽  
Agglomeration Effects ◽  
Static Annealing ◽  
Grain Growth Kinetics ◽  
Grain Growth Behavior

AbstractThe grain growth behavior of polycrystalline MoSi2 and composites containing SiC particulates has been studied in the temperature range of 1200-1800°C during static annealing as well as under concurrent deformation conditions. Monolithic MoSi2, with ∼ 26 μm grain size appears to be extremely resistant to grain growth up to 1500°C. However, the grain growth rate above this temperature is quite rapid. When particulate reinforcements are used to reduce the grain size of MoSi2 to 4.4 μm, a stable microstructure is maintained up to 1500°C. Accelerated grain growth kinetics are observed at 1800°C under conditions of large plastic strain. This enhanced grain boundary mobility is associated with particle sweeping and particle agglomeration effects. At lower temperatures, where dislocation creep is the more dominant deformation mechanism these effects are absent. In the presence of a Si concentration gradient extremely high growth rates of columnar MoSi2 grains have been observed during reaction synthesis of MoSi2.

THERMAL STABILITY OF NANOCRYSTALLINE COPPER FILMS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3830-3835 ◽  
Author(s):  
PENG CAO ◽  
DELIANG ZHANG
Keyword(s):  
Activation Energy ◽  
Grain Size ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Phase Particle ◽  
Second Phase ◽  
Pinning Force ◽  
Nanocrystalline Copper ◽  
Grain Growth Kinetics ◽  
Kinetics Of

The grain growth kinetics of nanocrystalline copper thin film samples was investigated. The grain size of nanocrystalline copper samples was determined from the broadening of X-ray spectra. It was found that the grain size increased linearly with isothermal annealing time within the first 10 minutes, beyond which power-law growth kinetics is applied. The activation energy for grain growth was determined by constructing an Arrhenius plot, which shows an activation energy of about 21 – 30 kJ/mol. The low activation energy is attributed to the second phase particle drag and the porosity drag, which act as the pinning force for grain growth in nanocrystalline copper.

β Grain Growth Kinetics of a New Metastable β Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 844-849 ◽  
Author(s):  
Yue Fei ◽  
Xin Nan Wang ◽  
Zhi Shou Zhu ◽  
Jun Li ◽  
Guo Qiang Shang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Grain Growth ◽  
Kinetic Equations ◽  
Type Equation ◽  
Growth Exponent ◽  
Solution Treated ◽  
Growth Activation ◽  
Grain Growth Kinetics ◽  
Kinetics Of ◽  
Strength And Ductility

Ti-Mo-Nb-Cr-Al-Fe-Si alloy is a new metastable β titanium alloy with excellent combination of strength and ductility. The β grain-growth exponent and the activation energies for β grain growth for the investigated alloy at specified temperature were computed by the kinetic equations and the Arrhenius-type equation. The rate of β grain growth decreases with elongating solution treated time and increases with the increasing solution-treated temperature. The β grain-growth exponents, n, are 0.461, 0.464 and 0.469 at 1113, 1133 and 1153K, respectively. The β grain growth activation energy is determined to be 274 KJ/mol.

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