The Experts below are selected from a list of 5862 Experts worldwide ranked by ideXlab platform
Zhangxing He - One of the best experts on this subject based on the ideXlab platform.
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Improvement of sinterability of BaZr0.8Y0.2O3-δ for H2 separation using Li2O/ZnO dual-Sintering Aid
Ceramics International, 2018Co-Authors: Yuehua Li, Wei Meng, Wenjie Yang, Ling Wang, Zhangxing HeAbstract:Abstract Li2O/ZnO was used as a dual-Sintering Aid to improve Sintering performance of BaZr0.8Y0.2O3-δ electrolyte (BZY). The influences of the Li/Zn ratios on sinterability, phase composition, microstructure and electrochemical properties of BZY electrolyte were investigated. Using Li2O/ZnO as a dual-Sintering additive, high density BZY ceramics were obtained at reduced temperature. The BZY samples added Li2O/ZnO dual-Sintering Aid had better performance than that using Li2O or ZnO single Sintering Aid. When total amount of Li and Zn in the form of oxides was controlled at 4 mol%, the BZY sample with the Li/Zn molar ratio of 1:1 achieved the highest relative density of 95.6% at temperature as low as 1400 °C and its total conductivity was found to be equal to 6.90 × 10−3 S cm−1 in wet air at 700 °C. The BZY samples also exhibited excellent chemical stability under CO2 or H2O atmosphere. These results showed that Li2O/ZnO was an excellent dual Sintering additive for lowering the Sintering temperature and increasing electrical conductivity of BZY. The hydrogen permeation performance of the above-mentioned BZY membrane with the Li/Zn molar ratio of 1:1 was evaluated using external short circuit method with porous Pt as catalyst and sliver sealing layer as electronic conductor. It was observed that hydrogen permeation flux increased with the increasing of temperature and hydrogen content in feed gas. When 50% H2–N2 was fed, the hydrogen flux reached 0.091 ml/min cm2 at 800 °C for the BZY membrane with a thickness of 1.0 mm.
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improvement of sinterability of bazr0 8y0 2o3 δ for h2 separation using li2o zno dual Sintering Aid
Ceramics International, 2018Co-Authors: Yuehua Li, Wei Meng, Wenjie Yang, Ling Wang, Zhangxing HeAbstract:Abstract Li2O/ZnO was used as a dual-Sintering Aid to improve Sintering performance of BaZr0.8Y0.2O3-δ electrolyte (BZY). The influences of the Li/Zn ratios on sinterability, phase composition, microstructure and electrochemical properties of BZY electrolyte were investigated. Using Li2O/ZnO as a dual-Sintering additive, high density BZY ceramics were obtained at reduced temperature. The BZY samples added Li2O/ZnO dual-Sintering Aid had better performance than that using Li2O or ZnO single Sintering Aid. When total amount of Li and Zn in the form of oxides was controlled at 4 mol%, the BZY sample with the Li/Zn molar ratio of 1:1 achieved the highest relative density of 95.6% at temperature as low as 1400 °C and its total conductivity was found to be equal to 6.90 × 10−3 S cm−1 in wet air at 700 °C. The BZY samples also exhibited excellent chemical stability under CO2 or H2O atmosphere. These results showed that Li2O/ZnO was an excellent dual Sintering additive for lowering the Sintering temperature and increasing electrical conductivity of BZY. The hydrogen permeation performance of the above-mentioned BZY membrane with the Li/Zn molar ratio of 1:1 was evaluated using external short circuit method with porous Pt as catalyst and sliver sealing layer as electronic conductor. It was observed that hydrogen permeation flux increased with the increasing of temperature and hydrogen content in feed gas. When 50% H2–N2 was fed, the hydrogen flux reached 0.091 ml/min cm2 at 800 °C for the BZY membrane with a thickness of 1.0 mm.
Eul Son Kang - One of the best experts on this subject based on the ideXlab platform.
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densification and mechanical properties of titanium diboride with silicon nitride as a Sintering Aid
Journal of the American Ceramic Society, 2004Co-Authors: June Ho Park, Cheol Seong Hwang, Eul Son KangAbstract:Titanium diboride (TiB2) was hot-pressed at a temperature of 1800°C, and silicon nitride (Si3N4) was added as a Sintering Aid. The amount of Si3N4 that was added had a significant influence on the sinterability and mechanical properties of the TiB2. When a small amount (2.5 wt%) of Si3N4 was added, the Si3N4 reacted with titania (TiO2) that was present on the surface of the TiB2 powder to form titanium nitride (TiN), boron nitride (BN), and amorphous silica (SiO2). The elimination of TiO2 suppressed the grain growth effectively, which led to an improvement in the densification of TiB2. The formation of SiO2 also was deemed beneficial for densification. The mechanical properties-especially, the flexural strength-were enhanced remarkably through these improvements in the sinterability and microstructure. On the other hand, when a large amount (greaterthan equal to5 wt%) of Si3N4 was added, the mechanical properties were not improved much, presumably because of the extensive formation of a glassy Si-Ti-O-N phase at the grain boundaries.
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Sintering and mechanical properties of titanium diboride with aluminum nitride as a Sintering Aid
Journal of The European Ceramic Society, 2002Co-Authors: Longhao Li, Eul Son KangAbstract:Abstract Titanium diboride (TiB 2 ) was hot-pressed at 1800 °C with aluminum nitride (AlN) as a Sintering Aid. The presence AlN had a strong influence on the sinterability and mechanical properties of the TiB 2 . When a small amount (⩽5 wt.%) of AlN was added to the TiB 2 the titania (TiO 2 ) present on the surface of the TiB 2 powder was eliminated by a reaction with AlN to form TiN and Al 2 O 3 . The elimination of TiO 2 markedly improved the sinterability and consequently the mechanical properties of TiB 2 . However, when too much AlN was added (⩾10 wt.%), the sinterability and the mechanical properties decreased, apparently due to the remaining unreacted AlN.
Yuehua Li - One of the best experts on this subject based on the ideXlab platform.
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Improvement of sinterability of BaZr0.8Y0.2O3-δ for H2 separation using Li2O/ZnO dual-Sintering Aid
Ceramics International, 2018Co-Authors: Yuehua Li, Wei Meng, Wenjie Yang, Ling Wang, Zhangxing HeAbstract:Abstract Li2O/ZnO was used as a dual-Sintering Aid to improve Sintering performance of BaZr0.8Y0.2O3-δ electrolyte (BZY). The influences of the Li/Zn ratios on sinterability, phase composition, microstructure and electrochemical properties of BZY electrolyte were investigated. Using Li2O/ZnO as a dual-Sintering additive, high density BZY ceramics were obtained at reduced temperature. The BZY samples added Li2O/ZnO dual-Sintering Aid had better performance than that using Li2O or ZnO single Sintering Aid. When total amount of Li and Zn in the form of oxides was controlled at 4 mol%, the BZY sample with the Li/Zn molar ratio of 1:1 achieved the highest relative density of 95.6% at temperature as low as 1400 °C and its total conductivity was found to be equal to 6.90 × 10−3 S cm−1 in wet air at 700 °C. The BZY samples also exhibited excellent chemical stability under CO2 or H2O atmosphere. These results showed that Li2O/ZnO was an excellent dual Sintering additive for lowering the Sintering temperature and increasing electrical conductivity of BZY. The hydrogen permeation performance of the above-mentioned BZY membrane with the Li/Zn molar ratio of 1:1 was evaluated using external short circuit method with porous Pt as catalyst and sliver sealing layer as electronic conductor. It was observed that hydrogen permeation flux increased with the increasing of temperature and hydrogen content in feed gas. When 50% H2–N2 was fed, the hydrogen flux reached 0.091 ml/min cm2 at 800 °C for the BZY membrane with a thickness of 1.0 mm.
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improvement of sinterability of bazr0 8y0 2o3 δ for h2 separation using li2o zno dual Sintering Aid
Ceramics International, 2018Co-Authors: Yuehua Li, Wei Meng, Wenjie Yang, Ling Wang, Zhangxing HeAbstract:Abstract Li2O/ZnO was used as a dual-Sintering Aid to improve Sintering performance of BaZr0.8Y0.2O3-δ electrolyte (BZY). The influences of the Li/Zn ratios on sinterability, phase composition, microstructure and electrochemical properties of BZY electrolyte were investigated. Using Li2O/ZnO as a dual-Sintering additive, high density BZY ceramics were obtained at reduced temperature. The BZY samples added Li2O/ZnO dual-Sintering Aid had better performance than that using Li2O or ZnO single Sintering Aid. When total amount of Li and Zn in the form of oxides was controlled at 4 mol%, the BZY sample with the Li/Zn molar ratio of 1:1 achieved the highest relative density of 95.6% at temperature as low as 1400 °C and its total conductivity was found to be equal to 6.90 × 10−3 S cm−1 in wet air at 700 °C. The BZY samples also exhibited excellent chemical stability under CO2 or H2O atmosphere. These results showed that Li2O/ZnO was an excellent dual Sintering additive for lowering the Sintering temperature and increasing electrical conductivity of BZY. The hydrogen permeation performance of the above-mentioned BZY membrane with the Li/Zn molar ratio of 1:1 was evaluated using external short circuit method with porous Pt as catalyst and sliver sealing layer as electronic conductor. It was observed that hydrogen permeation flux increased with the increasing of temperature and hydrogen content in feed gas. When 50% H2–N2 was fed, the hydrogen flux reached 0.091 ml/min cm2 at 800 °C for the BZY membrane with a thickness of 1.0 mm.
Hao Wang - One of the best experts on this subject based on the ideXlab platform.
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Microstructure and mechanical properties of super-hard B4C ceramic fabricated by spark plasma Sintering with (Ti3SiC2+Si) as Sintering Aid
Ceramics International, 2019Co-Authors: Qi Song, Zheng-yang Hu, Zhao-hui Zhang, Hao Wang, Zhen-wu MaAbstract:Abstract B4C ceramics were fabricated by spark plasma Sintering with 5% (Ti3SiC2+Si) as Sintering Aid. The effects of Sintering temperatures and Sintering Aid on microstructures and properties of B4C ceramics were investigated. The results indicated that the addition of a small amount of (Ti3SiC2+Si) could effectively improve the Sintering characteristic of B4C ceramics and reduce the Sintering temperature. The as-sintered ceramics fabricated at 1700 °C exhibited excellent mechanical properties, including a super-high Vickers hardness of 38.4 GPa, a high flexural strength of 457.6 MPa and a good fracture toughness of 5.61 MPa m0.5. Following reasons may be responsible for the improvement of the hardness of B4C ceramics: high relative density due to the combination use of (Ti3SiC2+Si) Sintering Aids and SPS technology, fine-grained structure of the B4C ceramics benefited from the low Sintering temperature, formation of the second phases TiB2 and SiC by chemical reaction and existence of the nano-sized unit of (TiB2+SiC) in B4C grains.
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microstructure and mechanical properties of super hard b4c ceramic fabricated by spark plasma Sintering with ti3sic2 si as Sintering Aid
Ceramics International, 2019Co-Authors: Qi Song, Zhao-hui Zhang, Shipan Yin, Hao WangAbstract:Abstract B4C ceramics were fabricated by spark plasma Sintering with 5% (Ti3SiC2+Si) as Sintering Aid. The effects of Sintering temperatures and Sintering Aid on microstructures and properties of B4C ceramics were investigated. The results indicated that the addition of a small amount of (Ti3SiC2+Si) could effectively improve the Sintering characteristic of B4C ceramics and reduce the Sintering temperature. The as-sintered ceramics fabricated at 1700 °C exhibited excellent mechanical properties, including a super-high Vickers hardness of 38.4 GPa, a high flexural strength of 457.6 MPa and a good fracture toughness of 5.61 MPa m0.5. Following reasons may be responsible for the improvement of the hardness of B4C ceramics: high relative density due to the combination use of (Ti3SiC2+Si) Sintering Aids and SPS technology, fine-grained structure of the B4C ceramics benefited from the low Sintering temperature, formation of the second phases TiB2 and SiC by chemical reaction and existence of the nano-sized unit of (TiB2+SiC) in B4C grains.
Yanchun Zhou - One of the best experts on this subject based on the ideXlab platform.
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preparation microstructure and mechanical properties of tib2 using ti3alc2 as a Sintering Aid
Journal of the American Ceramic Society, 2012Co-Authors: Liya Zheng, Fangzhi Li, Yanchun ZhouAbstract:Titanium diboride (TiB2) was successfully hot-pressed at 1500 degrees C using titanium aluminum carbide (Ti3AlC2) as a Sintering Aid. The mechanisms for the improved sinterability of TiB2 by the addition of Ti3AlC2 involve, first, the Al coming from the decomposition of Ti3AlC2 can eliminate the oxide layer on the surface of TiB2; second, the TiCx (also from the decomposition of Ti3AlC2) has a positive influence on the densification of TiB2 due to its plasticity at high temperatures. TEM observations reveal that the interface between TiB2 and TiCx is coherent and strong, free of amorphous layers and oxide phases. An optimized composition of TiB2-10 wt% Ti3AlC2 was obtained with the unique combination of mechanical properties, including the elastic modulus of 567 GPa, the fracture toughness of 4.8 MPa.m(1/2), the flexural strength of 711 MPa, and the hardness of 25 GPa.