scholarly journals Grain Growth Behavior of 0.95(Na0.5Bi0.5)TiO3–0.05BaTiO3 Controlled by Grain Shape and Second Phase

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1344 ◽  
Author(s):  
Sang-Chae Jeon ◽  
John G. Fisher ◽  
Suk-Joong L. Kang ◽  
Kyoung-Seok Moon
Keyword(s):  
Liquid Phase ◽  
Grain Growth ◽  
Growth Mechanism ◽  
Driving Force ◽  
Grain Shape ◽  
Growth Behavior ◽  
Second Phase ◽  
Two Dimensional ◽  
Grain Growth Behavior ◽  
Powder Compacts

The grain growth behavior of 0.95(Na0.5Bi0.5)TiO3 –0.05BaTiO3 (mole fraction, NBT–5BT) grains was investigated with excess Bi2O3 addition. The powder compacts of NBT–5BT were sintered at 1200 °C for various sintering times and with various amounts of Bi2O3 (0.1, 1.5, 4.0 and 10.0 mol%). When Bi2O3 was added to round-edged cubic NBT–5BT, the grain shape changed to a more faceted cube and the amount of liquid phase increased during sintering. A more faceted cubic grain shape indicates an increase in the critical driving force for appreciable growth of grains. However, obvious abnormal grain growth did not appear in any of the NBT–5BT samples with excess Bi2O3. The amount of liquid phase increased as the amount of Bi2O3 increased. Therefore, the rate of grain growth could be decreased by the increasing the distance for the diffusion of atoms. These observations allowed us to conclude that the growth of Bi2O3-excess NBT–5BT grains is governed by the growth of facet planes via the two-dimensional nucleation grain growth mechanism during changing grain shape and amount of liquid.

Boundary Structure-Dependent Grain Growth Behavior in Polycrystals: Model and Principle

2013 ◽  
Vol 753 ◽  
pp. 377-382 ◽  
Author(s):  
Suk Joong L. Kang
Keyword(s):  
Grain Growth ◽  
Microstructural Evolution ◽  
Driving Force ◽  
Coupling Effect ◽  
Normal Growth ◽  
Growth Behavior ◽  
Boundary Structure ◽  
Mixed Control ◽  
Grain Boundary Structure ◽  
Grain Growth Behavior

This paper reviews our recent investigations on grain growth in ceramics. Grain growth behavior has been found to be governed by the grain boundary structure: normal growth with a stationary relative grain size distribution for rough boundaries and non-normal (nonstationary) growth for faceted boundaries. Based on the concept of nonlinear migration of faceted boundaries, the mixed control model of grain growth is introduced and the principle of microstructural evolution is deduced. This principle states that various types of grain growth behavior are predicted as a result of the coupling effect between the maximum driving force for growth and the critical driving force for appreciable migration of the boundary. A wealth of experimental results supports the theoretical predictions of grain growth behavior, showing the generality of the suggested principle of microstructural evolution. Application of this principle is also demonstrated for the fabrication of single crystals as well as polycrystals with desired microstructures.

Effect of Grain Orientation on the Abnormal Grain Growth with Magetoplumbite Crystal Structure

2007 ◽  
Vol 558-559 ◽  
pp. 1265-1270 ◽  
Author(s):  
Sang Yeup Park ◽  
Jun Ho Song ◽  
Young Jin Cho
Keyword(s):  
Crystal Structure ◽  
Liquid Phase ◽  
Grain Growth ◽  
Grain Orientation ◽  
Grain Shape ◽  
Nucleation And Growth ◽  
Growth Behavior ◽  
Abnormal Grain Growth ◽  
Particle Orientation ◽  
Anisotropic Crystal

The nucleation and growth behavior of magentoplombite has been observed during the abnormal grain growth in the presence of liquid phase. Abnormal grain growth was explained in terms of grain orientation due to liquid phase. It has been observed that the nuclei formation for abnormal grain growth was driven by the capillary force due to the liquid phase. Because magnetoplumbite crystal structure has an anisotropic crystal nature, abnormal grain growth with faceted grain shape was observed depending on its chemical composition. The formation of nuclei and particle orientation was important for the occurrence of abnormal grain growth.

scholarly journals Effect of Wettability of Grains by a Liquid Phase on Grain Growth Behavior of La-Doped SrTiO3 Ceramics

1996 ◽  
Vol 104 (1213) ◽  
pp. 900-903 ◽  
Author(s):  
Yukiko FURUKAWA ◽  
Osamu SAKURAI ◽  
Kazuo SHINOZAKI ◽  
Nobuyasu MIZUTANI
Keyword(s):  
Liquid Phase ◽  
Grain Growth ◽  
Growth Behavior ◽  
Grain Growth Behavior ◽  
Srtio3 Ceramics ◽  
La Doped

Grain Growth Behavior of La0.6Sr0.4CoO3-δ Film Dispersed with a Second Phase

2019 ◽  
Vol 16 (44) ◽  
pp. 199-204 ◽  
Author(s):  
Takeyuki Sawada ◽  
Takaya Akashi
Keyword(s):  
Grain Growth ◽  
Growth Behavior ◽  
Second Phase ◽  
Grain Growth Behavior

Step Free Energy Change and Microstructural Development in BaTiO3-SiO2

2007 ◽  
Vol 352 ◽  
pp. 25-30 ◽  
Author(s):  
Jaem Yung Chang ◽  
Suk Joong L. Kang
Keyword(s):  
Free Energy ◽  
Grain Growth ◽  
Driving Force ◽  
Growth Behavior ◽  
Abnormal Grain Growth ◽  
Free Energy Change ◽  
Energy Change ◽  
Microstructural Development ◽  
Two Phase ◽  
Grain Growth Behavior

The effect of step free energy on the grain growth behavior in a liquid matrix is studied in a model system BaTiO3-SiO2. BaTiO3-10SiO2 (mole %) powder compacts were sintered at 1280°C under various oxygen partial pressures (PO2), 0.2, ~ 10-17 and ~ 10-24 atm. As the step free energy decreases with the reduction of PO2, it was possible to observe the change in growth behavior with the reduction of the step free energy. At PO2 = 0.2 atm, essentially no grain growth (stagnant grain growth) occurred during sintering up to 50 h. At PO2 ≈ 10-17 atm, abnormal grain growth followed stagnant grain growth during extended sintering (incubation of abnormal grain growth). At PO2 ≈ 10-24 atm, normal grain growth occurred. These changes in growth behavior with PO2 and the step free energy reduction are explained in terms of the change in the critical driving force for appreciable growth relative to the maximum driving force for grain growth. The present experimental results provide an example of microstructure control in solid-liquid two- phase systems via step free energy change.

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