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.

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 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.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

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