CERAMICS INTERNATIONAL
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2022
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IF 5.532
Haoran Li,Yan Liu,JinJing Yang,Ming Yuan,Anle Sun,Tiesong Lin,Xuejian Liu,Zhengren Huang
A new La 2 O 3 -doped Y 2 O 3 crucible materials was fabricated and evaluated by TiAl alloys melting test. Microstructure and properties of the La 2 O 3 -doped Y 2 O 3 ceramics were systemically investigated. In addition, interfacial reaction mechanism of the La 2 O 3 -doped Y 2 O 3 crucible materials and TiAl alloys, together with oxygen content of TiAl alloys were discussed. Solid solution of La 3+ in the crystal lattice of Y 2 O 3 significantly improved sintering properties of the La 2 O 3 -doped Y 2 O 3 crucible materials and decreased the open porosity. Compared with pure Y 2 O 3 , when adding 15 wt% La 2 O 3 , the open porosity and strength retention ration after thermal shock test of the La 2 O 3 -doped Y 2 O 3 crucible materials changed from 10.8% to 3.9% and from 64% to 78%, respectively. The interfacial reaction between La 2 O 3 -doped Y 2 O 3 crucible materials and TiAl alloys belongs to physical dissolution, and no reaction products were found during the melting of TiAl alloys. When using the 15 wt% La 2 O 3 -doped Y 2 O 3 crucible materials to melt TiAl alloys, oxygen content of the TiAl ingot declined to 530 ppm, which was only one fourth of that using pure Y 2 O 3 materials.
研究领域:
材料科学
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冶金工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2024
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IF 8.1
Jingjing Xie,Wei Jiang,Fei Tang,Ying Gao,Hongyu Li,Jiyang Li,Deyang Zhao,Zhiqiang Lv,Zhenglong Yang,Yanbin Xu
La 2 O 3 doped hollow porous Ni/NiCo 2 O 4 /C microspheres (NCO-La) are prepared by solvothermal method. The doping of porous La 2 O 3 nanoparticles is crucial to reduce the crystalline grain size of NiCo 2 O 4 and the internal resistance of the electrode, which facilitates ionic and electronic transportation efficiency. Hollow porous NCO-La microspheres with carbon networks have good mechanical strength and can effectively suppress volume expansion and aggregation. The combination of high-conductivity carbon and metallic nickel improves electronic conductivity. The nanostructure in the composite microspheres brings abundant active sites, which facilitates rapid redox of metal ions and allows rapid insertion and removal of Li + , consequently effectively improving the specific capacity. Benefiting from the synergy of well-designed nanostructure, the material shows high Li + storage performance and good stability. At 0.2 A g −1 after 250 cycles, the discharge specific capacity of NCO-La0.1 (1596.2 mAh g −1 ) is far better than NiCo 2 O 4 (655.6 mAh g −1 ) without La 2 O 3 doping. Such design concept of nanostructures provides a promising way to develop high-performance anode materials for LIBs.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
FUSION ENGINEERING AND DESIGN
·
2023
·
IF 1.7
Chan Wang,Ping Wang,Qing Yu Hou,Zhi Qiang Cui,Ning Fei Zhang,Lai Ma Luo,Zhen Yi Huang
In the present work, the feasibility and effectiveness of fabricating La 2 O 3 -doped W-based bulk using W-based composite powders of core-shell structure with W particle as a core and La(OH) 3 as a shell, without hydrogen reduction treatment, was evaluated. La(OH) 3 was first coated on the surface of pure W (uncoated) powders at a weight percentage of 3.50% to prepare composite (coated) powders using the electroless plating method. The uncoated and coated powders without being treated by hydrogen reduction were then sintered using spark plasma sintering (SPS) to fabricate bulks. The results showed that the core-shell structure with W particle as a core and La(OH) 3 film as a shell was fabricated. La 2 O 3 -doped W-based bulk with about 2.93 wt.% La 2 O 3 was obtained because of the transformation from La(OH) 3 to La 2 O 3 . The La 2 O 3 particles with larger sizes were distributed mainly at W grain boundaries and those with smaller sizes were distributed mainly inside W grains. The major densification mechanism of the sintered bulk from coated powders was the filling effect of La 2 O 3 particles on the pores as compared with the sintered bulk from uncoated powders, which could be evaluated by using a two-ball sintering neck model. The relative content of O in the form of WO 3 in the sintered bulk from coated powders was identical to that in the sintered bulk from uncoated powders. The W grain size of the sintered bulk from coated powders was smaller than that of the sintered bulk from uncoated powders. The thermal properties, mechanical properties, and irradiation properties of the sintered bulk from coated powders were all higher than those of the sintered bulk from uncoated powders. With the increase of sintering temperature, the evolution of the coated powders in the initial sintering period could be divided into six stages that were not completely independent and occurred in approximate sequence from the perspective of simplification. It was feasible and effective to fabricate La 2 O 3 -doped W-based bulk using the precursor W-based composite powders of core-shell structure with W particle as a core and La(OH) 3 as a shell without being treated by hydrogen reduction.
研究领域:
材料科学
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冶金工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2019
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IF 4.029
Zhaoyubo Zeng,Yunzhong Liu,Feng Qian,Jianxiu Guo,Min Wu
Yttria , yttria-ceria and yttria-ceria-lanthana stabilized zirconia powders were prepared by coprecipitation . Their tetragonal-to-monoclinic phase (t→m) transformation was investigated by calcining the powders in a temperature range of 400–1400 °C for 2 h. The results show that after doping with 0.1 to 0.3 mol.% La 2 O 3 and calcining at 1400 °C in air, unusual redox behaviours of cerium were detected in the 1.5 mol.% Y 2 O 3 +5.5 mol.% CeO 2 co-stabilized zirconia. Grain refinement and a sharp reduction in oxygen vacancy concentration were observed simultaneously. The t→m transition was not found in the 0.1 mol.% La 2 O 3 doped zirconia but appeared in the cases with a higher dopant content. The changes are discussed with regards to the grain size, valence change of cerium, presence of oxygen vacancies, and segregation of the dopants at grain boundaries.
研究领域:
材料科学
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无机化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
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2018
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IF 3.956
Qilei Yang,Ang Cao,Na Kang,Kang An,Zhao-Tie Liu,Yuan Liu
The catalyst for direct ethanol synthesis (DES) from syngas was investigated in this work, which is Co/La 2 O 3 -doped La 4 Ga 2 O 9 . The catalyst was prepared by using LaCo 1−x Ga x O 3 with perovskite phase as the precursor to intensify the interaction in the elements of Co, La and Ga. The catalysts were characterized by using XRD , H 2 -TPR, TEM , EDS, XPS , BET, ICP and TG techniques. This catalyst showed high selectivity to ethanol and excellent stability including excellent resistance to sintering and carbon deposition . It seems that the ethanol is generated in the interface between metallic Co and La 4 Ga 2 O 9 , and in the interface cobalt would be positively charged due to the interaction between Co nanoparticles and La 4 Ga 2 O 9 . The results and the related discussions indicate that Co/La 2 O 3 -doped La 4 Ga 2 O 9 catalyst is a promising catalyst for DES from syngas. Graphical abstracts.
研究领域:
催化
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）