PREPARATION OF Bi2O3-DOPED NiO/YSZ ANODE MATERIALS FOR SOFCs

2017 ◽  
Vol 24 (07) ◽  
pp. 1750092 ◽  
Author(s):  
FEI LI ◽  
JINGDE ZHANG ◽  
JUNPENG LUAN ◽  
YALEI LIU ◽  
JIANXUN HAN
Keyword(s):  
Weight Loss ◽  
Open Porosity ◽  
Anode Materials ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Sintering Aids ◽  
Dry Pressing ◽  
Sintering Properties ◽  
Cubic Structure ◽  
The Cost

The NiO/YSZ anode materials of SOFCs with Bi2O3 as sintering aids were successfully prepared by dry-pressing process. The effects of Bi2O3 content on the sintering properties of NiO/YSZ anode materials were studied, including the effects on the density, open porosity, weight loss, phase composition, microstructure, mechanical strength and electrical conductivity. In particular, the weight loss, relative density and bending strength of the sintered NiO/YSZ ceramics increased with the increase of Bi2O3 content while the open porosity decreased gradually. The density of the NiO–YSZ ceramics with 6[Formula: see text]wt.% Bi2O3 sintered at 1250[Formula: see text]C could reach that of the ceramics without Bi2O3 sintered at 1400[Formula: see text]C. For Bi2O3 concentration higher than 6[Formula: see text]wt.%, phase transformation of zirconia from monoclinic to cubic structure occurs, causing volume change and microcracks in the anode materials. Therefore, the optimum adding amount of Bi2O3 is 6[Formula: see text]wt.%, which can reduce the sintering temperature to 1250[Formula: see text]C. The ceramics with 6[Formula: see text]wt.% Bi2O3 have relatively high bending strength and low sintering temperature. This is of great significance for improving the performance of the anode and cutting the cost.

Effect of Sintering Aids on the Densification of Andalusite Ceramics

2013 ◽  
Vol 842 ◽  
pp. 78-82
Author(s):  
Jian Feng Wu ◽  
Hao Cheng ◽  
Xiao Hong Xu ◽  
Teng Fei Deng
Keyword(s):  
Bulk Density ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Potassium Feldspar ◽  
Optimal Composition ◽  
Sintering Aids ◽  
Sintering Aid ◽  
Large Bulk ◽  
Dry Pressing

The ceramics with large bulk density and high bending strength were fabricated via semi-dry pressing and pressureless sintering in the air. Andalusite and calcined bauxite were used as the raw materials, sintering aids such as potassium feldspar, albite, talc, spodumene and borax were added to promote the densification and decrease the sintering temperature of the samples. The best physical properties were obtained on a sample of optimal composition (the addition of sintering aid was talc) sintered at 1500 °C for 3 h, i.e. a bending strength of 138.52 MPa and bulk density of 2.61gcm-3, the sintering temperature was lower than sample without addition of sintering aid.

Fabrication of Stainless Steel Foams Using Polymeric Sponge Impregnation Technology

2014 ◽  
Vol 1035 ◽  
pp. 219-224 ◽  
Author(s):  
Hui Wang ◽  
Xiang Yang Zhou ◽  
Bo Long
Keyword(s):  
Stainless Steel ◽  
Apparent Density ◽  
Open Porosity ◽  
316L Stainless Steel ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Foam Sample ◽  
Cell Network ◽  
Mass Fractions ◽  
Steel Foam

316L stainless steel foams (SSFs) are fabricated successfully by polymeric sponge impregnation technology. The effects of mass fractions of PVA and powder on LOAD in impregnated sponge samples are investigated, and the effects of sintering temperature on apparent density, open porosity and bending strength of SSFs samples are also discussed. The experimental results show that the impregnated sponge samples may hold excellent 3D open-cell network structure and uniform muscles when the mass fractions of PVA and powder in slurry are kept in 9-13 % and 52-75% respectively; with rising the sintering temperature, the apparent density and bending strength of SSFs gradually increases, the open porosity reduces. After the temperature exceeds 1260°C, the bending strength reduces oppositely. A stainless steel foam sample with open porosity of 81.4% and bending strength of about 56.8 Mpa can be obtained after sintering at 1260 °Cfor 30min.

Effects of Adding Form of Additives on the Structure and Properties of High-Purity Alumina Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1130-1132
Author(s):  
Qiang Ren ◽  
Xiu Lan Wu ◽  
Xuan Meng He
Keyword(s):  
High Purity ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Normal Pressure ◽  
The Body ◽  
Raw Material ◽  
Sintering Process ◽  
Alumina Ceramics ◽  
Dry Pressing ◽  
Α Al2o3

High-purity alumina ceramics was prepared using high-purity α-Al2O3 powder as raw material, nitrates or oxides of magnesium, chromium and copper as additives by a wet ball milling with a later dry pressing forming and normal pressure sintering process. The influence of additives on the sintering temperature, microstructure and bending strength of the prepared alumina ceramics was studies. The results showed that the additive doped with nitrate can be dispersed uniformly in the body with molecule scale, and the oxides obtained by decomposing of nitrates have the higher reactivity. Thus, the nitrate additives have better capacity than oxide additives in reducing the sintering temperature and inhibiting the abnormal grain growth, and the alumina ceramics prepared by adding of nitrate additives have higher density and bending strength.

Fabrication Processes and Properties of Highly Pure MgAlON Materials

2007 ◽  
Vol 561-565 ◽  
pp. 543-546 ◽  
Author(s):  
Qing Huang ◽  
Yong Huang ◽  
Chang An Wang ◽  
Hou Xing Zhang
Keyword(s):  
Spark Plasma Sintering ◽  
Open Porosity ◽  
Single Phase ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Hot Press ◽  
Plasma Sintering ◽  
Short Period ◽  
Spark Plasma ◽  
Hot Press Sintering

In this paper, the MgAlON ceramic was fabricated by Spark Plasma Sintering (SPS) and hot press sintering respectively. The results showed that highly pure and single-phase MgAlON could be fabricated at lower sintering temperature in a short period through SPS process, compared with the conventional Hot Press sintering (HP) process. The bending strength of MgAlON specimens prepared by SPS process was higher than 500MPa while bending strength of HP specimens was much lower. The open porosity was almost eliminated in SPS MgAlON specimens. Spark Plasma Sintered MgAlON had a single phase of MgAlON while Hot Press Sintered MgAlON had major MgAlON and minor AlN and Al2O3.

Sintering Properties of Fused Silica/Nano-Zirconia Composite Ceramic

2013 ◽  
Vol 750-752 ◽  
pp. 81-84
Author(s):  
Yong Wu He ◽  
Jing Long Bu ◽  
Rui Sheng Wang ◽  
Dong Mei Zhao ◽  
Jun Xing Chen ◽  
...  
Keyword(s):  
Bulk Density ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Composite Ceramic ◽  
High Energy ◽  
Fused Silica ◽  
Raw Material ◽  
Composite Powders ◽  
Wet Chemical Synthesis ◽  
Sintering Properties

Zirconyl chloride was used as zirconium source and fused silica particles were used as main raw material. First of all, the composite powders were prepared by wet chemical synthesis using ammonia as the precipitator and polyethylene glycol as the dispersant. Then, fused silica nanozirconia composite ceramic containing nanometer particle zirconia with different contents (5%, 15%, 25% and 35%) were fabricated in reduction atmosphere at 1300°C, 1350°C and 1400°C for 1 h. The bulk density and bending strength were measured, microstructure was observed by SEM. The result indicated bulk density and bending strength of composite ceramic increase and microstructure becomes denser with content of zirconia increasing. Bulk density of composite ceramic increases and bending strength which reaches maximum at 1350°C firstly increases then decreases with the increase of sintering temperature. Both high sintering temperature and nanozirconia possessing high energy interface can improve the composite ceramic sintering.

Characteristics and firing behaviour of the under-Numidian clay deposits from the Jijel region (northeast Algeria): potential use in the ceramics industry

Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 325-337
Author(s):  
Abdelmalek Baghdad ◽  
Rekia Bouazi ◽  
Youcef Bouftouha ◽  
Frédéric Hatert ◽  
Nathalie Fagel
Keyword(s):  
Weight Loss ◽  
Water Absorption ◽  
Bulk Density ◽  
Bending Strength ◽  
Ceramic Tiles ◽  
X Ray ◽  
Clay Deposits ◽  
Dry Pressing ◽  
Firing Shrinkage ◽  
Ceramics Industry

AbstractThe Numidian Aquitano-Burdigalian nappe from the Jijel region (northeast Algeria) shows an important clay-rich basal series. In this study, seven representative clay samples were collected from the Djimla and El-Milia areas of this region in order to analyse their mineralogy using X-ray diffraction and Fourier-transform infrared spectroscopy, chemical composition by X-ray fluorescence, particle size, plasticity, morphology by scanning electron microscopy and their ceramic properties. Samples were prepared by pressing the clays and firing them at 800–1100°C, and bulk density, water absorption, linear firing shrinkage, weight loss and bending strength values were determined on the fired samples. The clays are mainly composed of kaolinite and illite, with a small amount of 10–14 Å interstratified clay minerals and chlorite, associated with quartz and feldspars. The main oxides in the samples were SiO2, Al2O3 and Fe2O3. The clays may be classified as moderately plastic according to their Atterberg limits. Ceramic tiles have been produced by dry pressing. At all tested firing temperatures, the clays present the required standard values for linear firing shrinkage, weight loss, bulk density, water absorption and bending strength, and they are defect-free. The main transformations were observed at 1000°C with the appearance of new crystalline phases. The measured technological properties of the investigated deposits confirm that the Numidian clays from the Djimla and El-Milia regions are suitable materials for the production of high-quality structural ceramics.

Microstructure and Properties of 8YSZ with High Component BAS

2014 ◽  
Vol 541-542 ◽  
pp. 25-29
Author(s):  
Jin Qin ◽  
Gang Chen ◽  
Zhi Ming Du ◽  
Jia Hong Niu
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
Sintering Process ◽  
Sintering Aids ◽  
Sintering Time ◽  
Material Component ◽  
Time Density ◽  
Very High

The sintering temperature of 8YSZ (8mol% yttrium stabilized zirconia) is very high, usually above 1500°C. BAS (BaO-Al2O3-SiO2) microcrystalline glass can be used as sintering aids to reduce the sintering temperature of 8YSZ. In this research, large proportion (30-50wt%) BAS was added in 8YSZ to observe the influence of the sintering aids. The change rules of mechanical properties such as density test, bending strength and toughness in different material component and sintering process were researched. The results show that physical and mechanical performance improvement with the increase of sintering temperature and sintering time, density and bending strength decreases with the increase of BAS mass fraction. The optimal mechanical properties are obtained by sintering temperature 1300°C, sintering time 0.5h and 30wt% BAS.

scholarly journals Effect of Li2O on Structure and Properties of Glass-Ceramic Bonds

2020 ◽  
Author(s):  
Zichen Guo ◽  
Feng He ◽  
Zuhao Li ◽  
Dongyang Yan ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Linear Shrinkage ◽  
Interfacial Bonding ◽  
Structure And Properties ◽  
Interfacial Bonding Strength ◽  
Wetting Property ◽  
Sintering Properties ◽  
Abrasive Tools

Abstract SiO2-B2O3-Al2O3-CaO vitrified bonds are widely used in the diamond abrasive tools preparation. The effect of Li2O on structure and properties of the glass-ceramic bonds was investigated. The structure of the glass-ceramic bonds was analyzed by XRD and FTIR. The bending strength, the sintering properties of different glass-ceramic bonds and the thermal expansion coefficient were tested at meantime. The sintering and interfacial bonding state between L-4 glass-ceramic bonds and diamond grains were observed by SEM. The results showed that with the increasing of Li2O, the sintering temperature of the glass-ceramic bonds was impactful reducing. When the content of Li2O was 4 wt%, the sintering temperature corresponding to the optimal bending strength was 630 °C, which had a certain reduction compared with other studies. The main crystal phase precipitated in the glass-ceramic bonds was LixAlxSi3−xO6. With the increase of Li2O, the number of crystals in the glass-ceramic bonds gradually increased. The highest bending strength could attain about 136 MPa. Meanwhile, the bending strength performed regular change as the rising of temperature accompanied by the linear shrinkage rate. The L-4 glass-ceramic bonds and diamond grains were found to have very good wetting property and the interfacial bonding strength was insured enhance. The average bending strength of the composite sinter of the glass-ceramic bonds and diamond was up to 87.8 MPa.

scholarly journals Preparation of gradient Ni-SDC anode by tape casting and co-sintering

2010 ◽  
Vol 42 (2) ◽  
pp. 153-159 ◽  
Author(s):  
X.B. Li ◽  
H.Y. Wang ◽  
H.X. Gu ◽  
J. Wang ◽  
W.J. Zhang ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Open Porosity ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Tape Casting ◽  
Sintering Process ◽  
Casting Method ◽  
Better Than

Gradient Ni-SDC anode and anode-supported SDC electrolyte were produced by tape casting method with laminating and co-sintering process. The best co-sintering temperature of gradient Ni-SDC anode and SDC electrolyte was 1300?C for 3 h. The open porosity of gradient Ni-SDC anode sintered at 1300oC was 36%, which offered sufficient open porosity of more than 30%. By adjusting the composition of Ni in gradient anode, the thermal expansion coefficient (TEC) of Ni-SDC anode could be adjusted close to that of SDC electrolyte, which improve the compatibility of anode and electrolyte. The bending strength of gradient Ni-SDC anode was 134 MPa. The electrical conductivity of gradient Ni-SDC anode was better than that of non-gradient Ni-SDC anode at 650 - 800?C.

The Study on the Property and the Microstructure of Pressureless Sintered h-BN Ceramics

2015 ◽  
Vol 1104 ◽  
pp. 9-14
Author(s):  
Xiao Ju Gao ◽  
Dong Ming Yan ◽  
Jian Wu Cao ◽  
Cong Zhang ◽  
Xiao Ming Mu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Hexagonal Boron Nitride ◽  
Pressureless Sintering ◽  
Sintering Aids ◽  
Lower Porosity ◽  
Moulding Pressure ◽  
House Structure ◽  
Sintering Method

Hexagonal boron nitride ceramic（h-BN）has been prepared by pressureless sintering method. The effect of sintering aids, moulding pressure and sintering temperature on the mechanical properties and microstructures of h-BN were investigated. The results show that the densification of as-prepared h-BN ceramic can be contributed to the addition of sintering-aids and the formation of card-house structure. Because of the high densification and card-house microstructure, the obtained h-BN demonstrates higher bending strength and lower porosity when the moulding pressure is 200MPa, sintering temperature is 1850°C and the contents of sintering aids is 10wt%.

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