SURFACE & COATINGS TECHNOLOGY
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2020
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IF 3.784
Yongchao Fang,Xiufang Cui,Guo Jin,Erbao Liu,Dan Zhang,Xin Wen,Qingbo Mi
In this work, hot corrosion behavior of air plasma sprayed La 0.8 Ba 0.2 TiO 3-δ (LBT)-YSZ double-ceramic-layer thermal barrier coating exposed to Na 2 SO 4 + V 2 O 5 molten salt at 900 °C for 20 h was investigated. The phase characterization and microstructural evolution analysis of the coating was carried out after the hot corrosion test by using X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the LBT-YSZ coating possessed excellent hot corrosion resistance compared with the conventional pure YSZ coating. The conventional pure YSZ coating was completely destroyed after the 10 h test due to the volume change resulting from the adverse phase transition. However, the situation for the LBT-YSZ coatings is completely opposite. The LBT-YSZ coating could prevent the YSZ interlayer underlying the LBT overlayer from densification for at least 20 h. In the LBT overlayer, the double-reaction-layer composed of under dense layer and upper porous layer was formed. In particular, the continuous dense layers with a thickness of ~100 μm formed after 10 h, effectively arresting further penetration of the molten salt. In addition, affected by the diffusion extent of SO 3 gas, the corrosion products of porous layer were composed of Ba 2 V 2 O 7 , LaVO 4 , TiO 2 and BaSO 4 , while those of dense layer consisted of Ba 2 V 2 O 7 , LaVO 4 and TiO 2 . The specific mechanism by which the corrosion reaction occurred was proposed based on Lewis acid-base rule and thermodynamics.
研究领域:
材料科学
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表面工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
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IF 4.527
Bao Zhang,Jiusan Xiao,Shuqiang Jiao,Hongmin Zhu
A unique phenomenon of TiC–TiO 2 reaction at 900 °C is established, forming a quasi-pure phase of abnormal titanium oxycarbide, since it is commonly synthesized at temperatures above 1500 °C. Impurity of Magnéli phase (Ti n O 2 n -1 , 4≤ n ≤9) is also detected in the product. Thermodynamics analysis indicates that the critical C/O concentration of titanium oxycarbide ( x in TiC x O 1- x ) equilibrated with Magnéli phase at 900 °C is around 0.66, typically 0.651 for Ti 4 O 7 . The obtained titanium oxycarbide phase contains metal-vacancy in Ti site, as Ti 1- y C x O 1- x which is reported the first time, differing from stoichiometric vacancy of both Ti site and C/O site in conventional TiC x O 1- x . The dominating part of TiC–TiO 2 reaction at 900 °C is reaction via solid solution as directly introducing the Ti and O atoms of TiO 2 into the FCC structure of TiC, which leads to the formation of metal-vacancy without altering the original lattice size, instead maintaining at the same level of TiC regardless of the variation of corresponding C/O concentration. The obtained maximum concentration of metal-vacancy in Ti 1- y C x O 1- x is 18%, close to the theoretical capacity of 18.9% which exists when the starting molar ratio of TiC and TiO 2 is aiming to the formation of TiC 0.651 O 0.349 , as the critical composition equilibrated with Ti 4 O 7 . The stability of metal-vacancy in titanium oxycarbide is verified by first-principles calculation in the perspective of energy.
研究领域:
材料科学
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化学工程
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热力学
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固体化学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2026
·
IF 18.1
Sun Zongfu,Liu Huawei,Cheng Yihao,Li Huan,Han Zhiyuan,Tang Ying,Zhang Xiang,Shi Chunsheng,He Fang,Yang Yuting,Chen Biao,He Chunnian
Hard carbon materials are promising candidates for advancing large-scale energy storage in sodium-ion batteries. However, a fundamental trade-off often exists between sodium storage sites and fast diffusion kinetics in hard carbon. Herein, we overturn this long-standing constraint through a machine learning design paradigm and low-temperature thermal-force coupling carbonization that enables the microstructure in hard carbon of both abundant sodium storage sites and rapid Na + diffusion. Benefiting from this low-temperature construction, the sodium-ion pouch cell exhibits a high specific energy (based on the entire cell) of 208.1 Wh kg −1 at 1.5-4.3 V. Besides, the required carbonization temperature reduces from 1300 °C to 900 °C, leading to an energy consumption reduction of 49.7% and a carbon emission reduction of 47.5%. This work not only provides a double-field regulation strategy to prepare high-performance hard carbon under low temperature, but also contributes a viable pathway toward sustainable sodium-ion batteries.
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2022
·
IF 6.371
Yang Yu,Xiaoping Cai,Xinyang Jiao,Chengyi Xu,Jinan Niu,Peizhong Feng
Ni-Al-Cr intermetallic compounds are candidate at extreme environment due to their excellent oxidation resistance at high temperature, and the oxidation resistance of Ni-Al-Cr alloy system has been studied extensively. However, the research on oxidation resistance mechanism of porous Ni-Al-Cr intermetallic compounds is still not deep. In our work, porous Ni-Al-Cr intermetallic compounds were synthesized by thermal explosion, and the oxidation resistance of porous Ni-Al-Cr system was mainly investigated. The results indicate that Cr promotes the formation of highly protective continuous Al 2 O 3 layer, increasing the oxidation resistance at 900 °C of porous Ni-Al-Cr. After oxidation at 900 °C for 120 h, the minimum mass gain of Ni-Al-Cr products is only 6.96%.
研究领域:
材料科学
·
高温材料
·
腐蚀与防护
✓ 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）