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

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.

scholarly journals Effect of Cold-Deformation on Austenite Grain Growth Behavior in Solution-Treated Low Alloy Steel

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1004 ◽  
Author(s):  
Xianguang Zhang ◽  
Kiyotaka Matsuura ◽  
Munekazu Ohno
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Grain Growth ◽  
Cold Deformation ◽  
Growth Behavior ◽  
Low Alloy Steel ◽  
Solution Treated ◽  
Austenite Grain ◽  
Grain Growth Behavior ◽  
Austenite Grain Growth

The occurrence of abnormal grain growth (AGG) of austenite during annealing is a serious problem in steels with carbide and/or nitride particles, which should be avoided from a viewpoint of mechanical properties. The effects of cold deformation prior to annealing on the occurrence of AGG have been investigated. It was found that the temperature range of the occurrence of AGG is shifted toward a low temperature region by cold deformation, and that the shift increases with the increase of the reduction ratio. The lowered AGG occurrence temperature is attributed to the fine and near-equilibrium AlN particles that are precipitated in the cold-deformed steel, which is readily dissolved during annealing. In contrast, coarse and non-equilibrium AlN particles precipitated in the undeformed steel, which is resistant to dissolution during annealing.

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