Effects of Compound Additives on Properties of Cermet Inert Anodes

2013 ◽  
Vol 634-638 ◽  
pp. 1910-1913
Author(s):  
Fu Xiang Wei ◽  
Gen Xi Yu ◽  
Zhi Ling Wang
Keyword(s):  
Particle Size ◽  
Significant Enhancement ◽  
Inert Anodes ◽  
Particle Size Gradation

In this paper, a combination of a two-step sintering and a particle size gradation technique was used to prepare cermet samples. The effects of compound additives with various combination of SnO2 and BaO on the performance of cermet were investigated. The results showed that, the performance of cermet could be improved by doping compound additives. The density of cermet sample reached to 5.61g•cm-3, and the porosity fell to 2.01%. Furthermore, we did observe a significant enhancement in its conductivity. The sample with 1% BaO additive has the highest conductivity at 8.02S/cm at 960°C, is increased by about 36% compared with the BaO undoped cermets.

scholarly journals Experimental Study on Nonlinear Seepage Characteristics and Particle Size Gradation Effect of Fractured Sandstones

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Xuyang Shi ◽  
Wei Zhou ◽  
Qingxiang Cai ◽  
Xiang Lu
Keyword(s):  
Particle Size ◽  
Fractal Dimension ◽  
Fractured Rock ◽  
Average Pore Size ◽  
Fractured Rock Mass ◽  
Average Pore ◽  
Seepage Pressure ◽  
Seepage Characteristics ◽  
Fractured Sandstone ◽  
Particle Size Gradation

Seepage mutation of fractured rock mass is one of the main inducements of dump slide and other disasters. Pore structure is a significant factor affecting the seepage characteristics of fractured rock mass, while particle size gradation has an important effect on the distribution of pore structure. Through the self-developed experimental system, the nonlinear seepage test on the fractured sandstones of the coalseam roof was conducted to investigate the influence of seepage pressure, porosity, and fractal dimension. Besides, the nonlinear seepage model was established by Barree–Conway theory. The results showed that, during the seepage process of fractured sandstone, there were significant nonlinear characteristics, which increased with the increase of the seepage pressure. With the increasing porosity, there was greater average pore size of fractured sandstone, stronger permeability, and weaker nonlinear seepage. The seepage characteristics approximated to that of Darcy model. However, with increasing grading fractal dimension, there were smaller average pore size of fractured sandstone, weaker permeability, and stronger nonlinear seepage. The seepage characteristics approximated to that of Forchheimer model.

Microstructure Modification of NiO/YSZ Anode in Solid Oxide Fuel Cell by Particle Size Gradation of YSZ

2012 ◽  
Vol 519 ◽  
pp. 32-35
Author(s):  
Qi Bing Chang ◽  
Xia Wang ◽  
Jian Er Zhou ◽  
Yong Qing Wang ◽  
Guang Yao Meng ◽  
...  
Keyword(s):  
Particle Size ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Bending Strength ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Mass Ratio ◽  
Obvious Effect ◽  
Microstructure Modification ◽  
Particle Size Gradation

The idealized microstructure of NiO/YSZ anode of solid oxide fuel cell (SOFC) is that YSZ structures the bone of the anode and NiO is segregated by YSZ to keep Ni from congregation. To obtain this microstructure, the mixture of coarse YSZ and fine YSZ was used. The effect of the particle size gradation of YSZ on the microstructure of anode was studied. The results show that the homogenous microstructure can be obtained when the mass ratio of the coarse YSZ (d50＝3.38µm) to the fine YSZ (d50＝0.4µm) is 7:3. The pre-sintering temperature has obvious effect on the porosity of the NiO/YSZ. The bending strength of NiO/YSZ and Ni/YSZ are 123MPa and 85MPa, respectively. The reduction of NiO to Ni has less effect on the bending strength for 40vol%Ni/YSZ (7/3).

Effect of AlF3 Addition on Electric Conductivity of NiFe2O4-Based Cermet Inert Anode

2014 ◽  
Vol 881-883 ◽  
pp. 1391-1395
Author(s):  
Fu Xiang Wei ◽  
Gen Xi Yu ◽  
Zhi Ling Wang
Keyword(s):  
Particle Size ◽  
Electric Conductivity ◽  
Inert Anode ◽  
Metallic Phase ◽  
Ceramic Phase ◽  
Ceramic Particles ◽  
Pure Sample ◽  
The Impact ◽  
Particle Size Gradation ◽  
Better Than

In this study, a combination of a two-step sintering and a particle size gradation technique was used to prepare cermet samples. We focused on the impact of the AlF3 additive on the performance of the cermet. We found that the addition of AlF3 doesnt significantly improve the density and porosity of Ag-NiFe2O4, since the addition of the AlF3 did not reduce the particle size, nor did it promote the tight packing of NiFe2O4 in a spinel-based cermet. However, we did observe a significant enhancement in its conductivity. The sample with 3% additive has the highest conductivity at 22.53S·cm-1 at 900°C, nearly 3.8 times better than the pure sample. An Analysis of the cermet microstructure showed that adding AlF3 can improve wetting between the ceramic phase and the silver metallic phase. It also facilitates the distribution of silver along the contour of the ceramic particles, which contributes to the improved conductivity of the nickel-based cermet.

scholarly journals Effect of Particle-Size Gradation on Coarse Sand-Geotextile Interface Response in Cyclic and Postcyclic Direct Shear Test

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jun Wang ◽  
Meng-Jie Ying ◽  
Fei-Yu Liu ◽  
Hong-Tao Fu ◽  
Jun-Feng Ni ◽  
...  
Keyword(s):  
Particle Size ◽  
Shear Stress ◽  
Shear Strength ◽  
Shear Behaviour ◽  
Direct Shear ◽  
Interface Shear ◽  
Cycle Number ◽  
Cyclic Shear ◽  
Stress Degradation ◽  
Particle Size Gradation

In order to investigate the influence of sand particle-size gradation on cyclic and postcyclic shear strength behaviour on sand-geotextile interfaces, a series of monotonic direct shear (MDS), cyclic direct shear (CDS), and postcyclic direct shear (PCDS) tests were performed using a large-scale direct shear apparatus. The influence of cyclic shear history on the direct shear behaviour of the interface was studied. The results indicated that cyclic shear stress degradation occurred at the sand-geotextile interface. Shear volumetric contraction induced by the cyclic direct shear increased with the increase in cycle number. The lowest final contraction value was observed in discontinuously graded sand. In the MDS tests, there were great differences in interface shear strength due to the different particle-size gradations, whereas the differences between shear volumes were negligible. In the PCDS tests, the shear stress-displacement curves exhibited postpeak stress hardening behaviour for different particle-size gradations, and differences in shear volumes were detected. The well-graded sand-geotextile interface had a higher value of shear stiffness and a higher damping ratio relative to the other interfaces. Postcyclic shear stress degradation was observed for the discontinuously graded sand-geotextile interface.

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