Effect of sintering temperature and P2O5 concentration on the grain shape and grain growth behavior in the ZnO–P2O5 system

2014 ◽  
Vol 40 (7) ◽  
pp. 10143-10147
Author(s):  
Im-Sic Choi ◽  
Joon-Hyung Lee ◽  
Young-Woo Heo ◽  
Jeong-Joo Kim
Keyword(s):  
Grain Growth ◽  
Grain Shape ◽  
Sintering Temperature ◽  
Growth Behavior ◽  
Grain Growth Behavior ◽  
P2o5 System

Grain Growth Behavior of Al2O3-ZrO2 with a Small Amount of Zirconia

2007 ◽  
Vol 561-565 ◽  
pp. 535-538 ◽  
Author(s):  
M. Nagashima ◽  
Motozo Hayakawa
Keyword(s):  
Growth Inhibition ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Sintering Temperature ◽  
Growth Behavior ◽  
Pinning Effect ◽  
Grain Growth Behavior ◽  
Good Agreement ◽  
Zirconia Content

Grain growth behavior in Al2O3 with a small amount of ZrO2 (< 5 vol%) was examined. Grain growth of Al2O3 was retarded by zirconia particles, despite the small amount of added zirconia. The fraction of the zirconia particles embedded within alumina grains (intragranular zirconia particles) increased with decreasing zirconia content and increasing sintering temperature. Grain growth inhibition of alumina in the Al2O3-ZrO2 showed good agreement with the prediction of modified Zener’s pinning effect by the zirconia particles on grain boundaries.

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 Microstructure and Magnetic Properties of La-Ca-Co Substituted M-Type Sr-Hexaferrites with Controlled Si Diffusion

2020 ◽  
Vol 10 (21) ◽  
pp. 7570
Author(s):  
Kyoung-Seok Moon ◽  
Pyeong-yeol Yu ◽  
Young-Min Kang
Keyword(s):  
Grain Growth ◽  
Sintering Temperature ◽  
Material Design ◽  
Bimodal Distribution ◽  
Growth Behavior ◽  
Diffusion Behavior ◽  
Grain Growth Behavior ◽  
Type Lattice ◽  
Cell Volumes ◽  
Microstructure And Magnetic Properties

La-Ca-Co substituted M-type Sr-hexaferrites (Sr0.3Ca0.4La0.3Fe9.8Co0.2O19-δ) were prepared by a solid-state reaction using two different procedures, where the SiO2 additive was mixed either before calcination (pre-Si) or after calcination (post-Si). At the same sintering temperature, smaller cell volumes and reduced saturation magnetization (Ms) values were obtained for samples processed with the pre-Si method than those with the post-Si method. This implied that the pre-Si method resulted in a greater degree of Si substitution into the M-type lattice and increased Fe extrusion out of the lattice. The grain growth behavior was controlled by the SiO2 amount and sintering temperature. It was found that abnormal grains occur with a bimodal distribution in the 0.5 wt% SiO2 samples sintered at 1240 °C, due to the increased critical driving force for growth caused by an increased amount of SiO2 addition. The Ms and coercivity values were altered with the control of Si diffusion and abnormal grain growth. The control of the additive diffusion behavior is one of the important keys in the material design under same materials compositions.

Grain Growth Behavior and Characteristics of Multiphase Ceramic Composites Fabricated by Organic-Inorganic Solution Technique

2007 ◽  
Vol 558-559 ◽  
pp. 1249-1253
Author(s):  
Sang Jin Lee
Keyword(s):  
Polyethylene Glycol ◽  
Flexural Strength ◽  
Grain Growth ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
Milling Process ◽  
Growth Behavior ◽  
Solution Technique ◽  
Polymeric Carrier ◽  
Grain Growth Behavior

Multi-component ceramic composites consisting of two, three and four phases, based on duplex microstructures of zirconia and alumina, were fabricated by a polymer complexation route employing polyethylene glycol (PEG) as a polymeric carrier. The polymer complexation route provided porous and soft powders and they were sintered after a simple ball milling process. In this study, the microstructures and flexural strengths of the multi-component (Al2O3-ZrO2-Y2O3-SrO) ceramic composites were examined on the processing variations of mole ratio and sintering temperature. The composites showed various grain morphologies according to the sintering temperature, and flexural strength of 410 MPa was obtained in the Al2O3·ZrO2·0.5Y2O3·0.4SrO composite sintered at 1600 °C for 1 h. In particular, needle-shape grains were observed in the four-component composites sintered at 1500 °C.

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