Sintering behavior of BaCe0.7Zr0.1Y0.2O3-δ electrolyte at 1150 °C with the utilization of CuO and Bi2O3 as sintering aids and its electrical performance

2021 ◽  
Author(s):  
Zaheer Ud Din Babar ◽  
Muhammad Bilal Hanif ◽  
Jiu-Tao Gao ◽  
Chang-Jiu Li ◽  
Cheng-Xin Li
Keyword(s):  
Electrical Performance ◽  
Sintering Behavior ◽  
Sintering Aids

Effect of the Rare Earth Oxides on Sintering Behavior and Microstructure of ZrB2-SiC Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1740-1742 ◽  
Author(s):  
Xue Ying Li ◽  
Jie Cai Han ◽  
Xing Hong Zhang ◽  
Xiao Guang Luo
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Rare Earth ◽  
Grain Growth ◽  
Rare Earth Oxides ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Sic Ceramics ◽  
Sic Composites ◽  
And Control

In this study, two rare earth oxides, Y2O3 and La2O3, are used as the additives in the sintering of ZrB2-SiC composites to improve the sinterability and control development of microstructure during densification. The results show that the use of rare earth oxides (5vol.%) improves the powder sinterability, hindered excessive growth of matrix particles and increase fracture toughness of ZrB2-SiC composites, in comparison to ZrB2-SiC with additions free. Nearly full dense materials are obtained by hot pressing at 1900°C. XRD analyses indicate that lanthanum-containing phases were formed in the composite with La2O3. Microstructure observations by SEM reveal that the grain size of ZrB2-SiC with Y2O3 and La2O3 composites are less than the sample without additives, which indicates Y2O3 and La2O3 may restrain the grain growth and increase the fracture toughness. The fracture toughness of ZrB2-SiC composites with Y2O3 and La2O3 reached 5.0MPa·m1/2 and 5.5MPa·m1/2 respectively. Therefore, the additive Y2O3 and La2O3 are very effective as sintering aids for the ZrB2-SiC composite.

Preparation of Bauxite-Based Homogenized Mullite Grogs with Bauxite and Coal Gangue

2011 ◽  
Vol 199-200 ◽  
pp. 1940-1944 ◽  
Author(s):  
Zhong Zheng Yang ◽  
Zhen Xian Xing ◽  
Zhan Fang Gai ◽  
Huan Qiang Liu
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Bulk Density ◽  
Sintering Temperature ◽  
Apparent Porosity ◽  
Heat Processing ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Homogenization Process ◽  
Three Stages

The sintering behavior, physical properties and heat processing changes of bauxite-based homogenized grogs prepared by homogenization process and high temperature sintering using bauxite as starting material were investigated. Results show that the bauxite-based mullite can be synthesized by the method, sintering temperature with and without MgO/CeO2sintering aids are 1600°C and 1700°C separately, the mullite with apparent porosity of＜1.0% and 2.5%, bulk density of ≥2.87g•cm-3and 2.75g•cm-3, Refracteriness-Under-Load(RUL) 1600°C and 1620С; changes in the heat processing is divided into three stages: dehydration stage(400°С~900°С ), primary mullitization stage(1000°С ~1200°С) and secondary mullitization stage(>1200°С).

scholarly journals Sintering Behavior of BST Nanoparticles at Low Temperature and Electrical Properties of their Ceramics

2020 ◽  
Author(s):  
Jianquan Qi ◽  
Yan Li ◽  
Mengyin Li ◽  
Jiahui Xie ◽  
Tianchi Yu ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Dielectric Constant ◽  
Alkaline Earth ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Bst Ceramics ◽  
Related Compounds ◽  
Alkaline Earth Cations

Abstract The powders of the Ba0.75Sr0.25TiO3 (BST) nanoparticles were directly synthesized by milling of Ba(OH)2·8H2O, Sr(OH)2·8H2O and Ti(BuO)4 in ethanol at room temperature. They have homogenous grains of ~15 nm and the high sintering activity. The dense ceramics with the density >90% can be obtained at a sintering temperature of ≤950 oC by them with adding 3 wt% sintering aids of Bi2O3 and Li2CO3. The sintering behavior of the BST nanoparticles by adding the aids of Bi2O3 and Li2CO3 is studied carefully. Several Bi-related compounds are involved in the sintering procedure at a different temperature. They enhance the mass transfer and promote the sintering densification. These compounds such as Ba2BiO4 and SrBiO4 appear at 800 oC, LiBa4Bi3O11 and Sr1.2Bi0.8O3 appear over 830 oC, and Bi8.11Ba0.89O13.05 appears at 950 oC. The cation Bi in the ceramics has mixture valences of 3+ and 5+. It makes the ceramics as semiconducting state with the dark gray color and decreases the ceramics resistivities. With the sintering temperature increase, especially at 950 oC, the cation Bi tends back to single valence of +3 in the ceramics. The most of alkaline earth cations in Bi-related compounds will release and resorb into the lattice of BST and drive the densification of the nanoparticles. The BST ceramics can have a peak dielectric constant >6500 at 53 oC, loss <0.025, and resistivity >1012 W·cm when sintered at a temperature of ≥900 oC with 3 wt% sintering aids. They have a potential application for multiple layer ceramic capacitors (MLCC) with silver inner-electrodes.

Liquid Phase Sintering of α-Si3N4 by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 1062-1064 ◽  
Author(s):  
Fa Qiang Yan ◽  
Fei Chen ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Liquid Phase ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Factors Influencing ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Si3n4 Ceramics

In this study, spark plasma sintering (SPS) was applied to prepare α-Si3N4 ceramics of different densities with magnesia, silicon dioxide, alumina as the sintering aids. The sintering behavior and liquid phase sintering (LPS) mechanism were discussed and the factors influencing the density of the prepared samples were analyzed. Microstructures of sintered samples were observed and the phase compositions were analyzed. The results showed that α-Si3N4 ceramics can be sintered by SPS based on the reaction among α-Si3N4 and sintering additives which lead to the liquid phase and the density can be well controlled from 2.48 to 3.09 g/cm3 while the content of the sintering aids changes from 10% to 28.5% and sintering temperature from 1400°C to 1500°C.

Pressureless Sintering of Boron Carbide with Al2O3 and SiC as Sintering Aids

2014 ◽  
Vol 602-603 ◽  
pp. 202-207
Author(s):  
Xiao Guang Li ◽  
Dong Liang Jiang ◽  
Jing Xian Zhang ◽  
Qing Ling Lin ◽  
Zhong Ming Chen ◽  
...  
Keyword(s):  
Boron Carbide ◽  
Microstructure Evolution ◽  
Bending Strength ◽  
Linear Shrinkage ◽  
Shrinkage Rate ◽  
Sintering Behavior ◽  
Pressureless Sintering ◽  
Sintering Aids ◽  
Sintering Additives

The effect of Al2O3 and SiC as the sintering additives for pressureless sintering boron carbide (B4C) was investigated. The aids were 10 wt% Al2O3 (10A), 10 wt% Al2O3 and 15 wt% SiC (10A15S), 10 wt% Al2O3 and 30 wt% SiC (10A30S), and 30 wt% SiC (30S) (all based on B4C). The sintering behavior, microstructure evolution and phase compositions of the samples were studied. 10A15S and 10A30S can effectively enhance the densification of B4C, comparing with 10A and 30S. The linear shrinkage rate of 14% for the 10A15S and 10A30S samples can be reached. The bending strength approaching 400MPa for the 10A30S sample sintered at 2170°C can be obtained.

Sintering Behavior of High Purity Nano-Yttria (Y2O3) Powder Without Sintering Aids

2018 ◽  
Vol 10 (1) ◽  
pp. 95-98
Author(s):  
Mircea Cristian Pantilimon ◽  
Tea Sung Kang ◽  
Sang-Jin Lee
Keyword(s):  
High Purity ◽  
Sintering Behavior ◽  
Sintering Aids

Liquid Phase Sintering of Aluminum Nitride

2007 ◽  
Vol 554 ◽  
pp. 181-188 ◽  
Author(s):  
Katsutoshi Komeya ◽  
Junichi Tatami
Keyword(s):  
Liquid Phase ◽  
Aluminum Nitride ◽  
Dihedral Angle ◽  
Lattice Constant ◽  
Sintered Density ◽  
Liquid Phase Sintering ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Powder Compacts ◽  
Oxygen Impurities

Liquid-phase sintering of aluminum nitride (AlN) with additives was reviewed. The most important innovation was the discovery of critical sintering aids for AlN densification, specifically rare-earth compounds and alkali-earth compounds. These additives are extremely valuable for increasing thermal conductivity by trapping and removing oxygen in the AlN lattice during firing. Consequently, thermal conductivities in AlN ceramics of 100 to 260W/mK were developed. We also studied the effects of parameters such as raw powder, additives, composition, and firing condition in liquid-phase sintering with AlN-sintering aids, focusing on oxygen impurities in the system. The sintering behavior of powder compacts was investigated by evaluating the densification, the lattice constant c for AlN, and the dihedral angle of the interface between the AlN grains and the grain boundary liquid-phase. In our results, the change in densification was closely related to changes in the lattice constant c and the dihedral angle. That is, the sintered density increased with an increase in the oxygen dissolved in the AlN grains and with the improvement in wettability between the solid and liquid phase.

Sintering studies on ultrafine ZrB2 powder produced by a self-propagating high-temperature synthesis process

2000 ◽  
Vol 15 (11) ◽  
pp. 2499-2504 ◽  
Author(s):  
S. K. Mishra (Pathak) ◽  
S. Das ◽  
S. K. Das ◽  
P. Ramachandrarao
Keyword(s):  
High Temperature ◽  
Boron Oxide ◽  
Zirconium Dioxide ◽  
Fine Powder ◽  
Surface Oxidation ◽  
Synthesis Process ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

A detailed study on the sintering behavior of zirconium diboride powder produced by the self-propagating high-temperature synthesis (SHS) process was carried out in the temperature range of 1500–1800 °C. The fine powder prepared by the SHS process exhibited excellent sinterability and could be sintered at 1800 °C for 1 h to approximately 94% of the theoretical density. The apparent activation energy of densification in the range of 1500–1800 °C was estimated to be 248 ± 4 kJ mol−1. A zirconium dioxide layer formed on the surface of the sintered body and was attributed to boron oxide formation during sintering and concurrent surface oxidation by the oxygen generated from the reduction of boron oxide in the carbonaceous atmosphere. Sintering aids like Fe and Cr appeared to help in densification of ZrB2 powder.

Microstructure of dense MgO penetrated by a silicate liquid

1993 ◽  
Vol 51 ◽  
pp. 948-949
Author(s):  
Sundar Ramamurthy ◽  
Michael P. Mallamaci ◽  
C. Barry Carter ◽  
Peler R. Duncombe ◽  
Thomas M. Shaw
Keyword(s):  
Grain Boundaries ◽  
Ceramic Materials ◽  
Liquid Phase Sintering ◽  
Sintering Behavior ◽  
Triple Junctions ◽  
Sintering Aids ◽  
Liquid Phases ◽  
Polycrystalline Ceramic ◽  
The Subject ◽  
Sintered Product

Grain boundaries control most of the critical properties of ceramic materials and devices. The presence of an intergranular amorphous phase in many polycrystalline ceramic compacts has been reported. Grain boundaries may also involve regions of ordered structure and amorphous (glassy) phase. Dense polycrystalline compacts are processed by liquid-phase sintering routes. The addition of sintering aids such as CaO, MgO and SiO2 influence the densification process substantially. During sintering the grain boundaries are wet by liquid phases, and amorphous films are often found at the grain boundaries and triple junctions in the sintered product. The presence of such films not only influences the sintering behavior but it also affects the final properties in the sintered product. These films have therefore been the subject of intense investigation. Silicate-based compositions are the typical glass phases observed in these materials.In the present study, polycrystalline, dense MgO cubes have been penetrated by liquid monlicellite (CaMgSiO4) at 1700°C.

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