JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2024
·
IF 3.2
Bo Wang,Zihao Pan,Ziyan Zhao,Bo Zhou,Xuejian Liu,Zhengren Huang,Yan Liu
In this paper, we designed two series of the ZnO-B 2 O 3 -SiO 2 (ZBS) glass to explore their applicability for joining AlN ceramic. The density, flexural strength, structure, characteristic temperature, coefficient of thermal expansion (CTE) and crystallization behavior of the ZBS glass with varying ZnO and B 2 O 3 content were systematically studied. The results show that as B 2 O 3 content increase, the glass network is disrupted with the transition from three-dimensional shelf-like structure [BO 4 ] to two-dimensional layers [BO 3 ], increasing the number of the broken bonds, while an increase in ZnO results in a more compact glass network structure. We also found that both glass transition temperature (T g ) and softening temperature (T S ) exhibit a declining trend with the increase in B 2 O 3 and ZnO. Zn 2 SiO 4 and ZnAl 2 O 4 , began to precipitate after heat treatments in all the samples except 60ZnO-30B 2 O 3 –10SiO 2 (abbreviated as B30), where the diffraction peaks do not appear in Zn 2 SiO 4 but in Zn 4 B 6 O 13 . Notably, Zn 2 SiO 4 is the main phase for most samples while the main phase of B30 sample is ZnAl 2 O 4 . The CTE increases from 4.6 to 5.03 (× 10 –6 / °C) and 4.23 to 4.73 (× 10 –6 / °C) with an increase of B 2 O 3 and ZnO content, respectively. Among these, the CTE of B30 sample is compatible with that of AlN ceramic substrate. The optimal shear strength, 60.32±10.26 MPa, was achieved with B30 samples at 750 °C. The high strength was attributed to the interfacial reaction that leads to strong chemical bonding and the uniform distribution of the ZnAl 2 O 4 in the interlayer, which reinforces the strength of the interlayer itself.
研究领域:
材料科学
·
无机非金属材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
·
2025
·
IF 2
Zhang Dongbo,Tang Xinyue,Wang Ning,Xiao Mingwei,Yan Jiangrong,Zhang Yongsheng
High-entropy oxides used as thermal barrier coating materials have attracted considerable attention from scientific communities owing to their unique properties, such as low thermal conductivity and good stability at high temperatures. In this study, a new (La 0.2 Gd 0.2 Zr 0.2 Ce 0.2 Ho 0.2 )O 2-δ ((LGZCH)O) fluorite-structured high-entropy oxide was successfully synthesized through a solid-state reaction at 1400 °C. The resulting material demonstrated good phase stability after sintering at high temperatures. The microstructure, microscopic morphology, ionic valence, compositional distribution, optical properties, thermal conductivity, thermal expansion properties, and mechanical properties of (LGZCH)O were investigated. X-ray diffraction results showed that the (LGZCH)O fluorite-structured high-entropy oxide exhibited good stability during sintering at different temperatures with an optimum sintering temperature of 1580 °C. Ce 4+ converted to Ce 3+ at high temperatures. Scanning electron microscopy results showed that the material had a high porosity of approximately 28.9% after sintering at 1580 °C. (LGZCH)O had a higher infrared radiation emissivity of 82.2%-87.6% in the range of 2.5-6.0 μm indicating that it had better thermal radiation shielding performance. After porosity modification, the thermal conductivity ranged from 1.27 to 1.00 W m −1 K −1 from room temperature to 1000 °C, which is considerably lower than that of yttria-stabilized zirconia. Additionally, (LGZCH)O exhibited low coefficients of thermal expansion measuring 9.65 × 10 −6 K −1 and 10.13 × 10 −6 K −1 at 1000 and 1200 °C, respectively. The hardness and Young’s modulus of the bulk (LGZCH)O measured via nanoindentation tests were 8.86 GPa and 153.98 GPa, respectively, which are marginally inferior to those of YSZ. Therefore, (LGZCH)O can be considered a promising candidate material for thermal barrier coatings.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2021
·Vol. 306
·期 3
·2000606
·
IF 4.367
Pengfei Jiang,Jiulin Shen,Yao Wang,Jibin Zhang,Xiangfu Liu,Guoli Tu
Due to the development of dynamic flexible organic light-emitting diode displays, colorless polyimides (CPI) as the supporting or protecting optical films, are facing significant challenges due to the requirements of optical, mechanical, thermal, and chemical properties. Typical CPIs are derived from TFDB (2,2-bis(trifluoro-methyl)-4,4′-diaminobiphenyl)/6FDA (4,4′-(hexafluoroisopropylidene)diphthalic anhydride), which still need to be improved in both dimensional stability and optical performance. In this communication, a strong electron acceptor group, the sulfoxide bond, is first introduced into the TFDB block of CPI chains. Based on this introduction, the distribution of the electron cloud in the polymer chain is reconstructed under the strongly pulling electron effect, and the spatial conformation of the polymer chain is also affected by the rigid and twisted sulfoxide group. The influences on CPI's optical properties, especially the refractive index and the retardation, are studied and discussed in detail by experimental results and theoretical calculations. It is shown that the CPI with the sulfoxide group exhibits higher optical transparency, lower yellow index, phase retardation and coefficient of thermal expansion, which is an ideal material for CPI optical films.
研究领域:
材料科学
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光学工程
·
高分子化学
✓ 已验证
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Qingshan Liu,Jiamin Chu,Xiaoxi Yang,Yulu Huang,Mingxing Zhao,Qige Zheng,Yanxia Qi
The density of two functionalized ionic liquids (FILs) 1-methoxyethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([MOEmim][NTf 2 ] and 1-methoxyethyl-2,3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide [MOEmmim][NTf 2 ]) have been measured with ether solvents proprylene glycol monomethyl ether (PEGMME), diethylene glycol dimethyl ether (DEGDME), tetraethylene glycol dimethyl ether (TEGDME) at diluted concentration range. The determined temperature range is from 293.15 to 328.15 K at atmospheric pressure. The measured densities are used for the calculation of apparent molar volumes, V ϕ /m 3 ·mol −1 , at the temperature range. The effects of the ether ( O ) and methyl ( CH 3 ) introduction on imidazolium cation are discussed for the density and apparent molar volume in deeply. The Redlich-Rosenfeld-Meyer (RRM) equation was used for the fitting of apparent molar volumes, V ϕ /m 3 ·mol −1 , for the six studied dilute solutions. The infinite dilution apparent molar volumes, V ϕ /m 3 ·mol −1 , and limiting apparent molar expansibility, E Φ 0 / c m 3 · m o l - 1 · K - 1 , have been obtained and discussed from the RRM equation and polynomial equation. The thermal expansion coefficients, α/K −1 , have also been calculated and discussed from density for the studied dilute solutions in the temperature range.
研究领域:
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Kailong Yang,Lin Chen,Fushuo Wu,Qi Zheng,Jianyu Li,Peng Song,Yanfei Wang,Rongjun Liu,Jing Feng
Monoclinic (m) and monoclinic-prime (m′) phases of Yb(Ta x Nb 1− x )O 4 ceramics were synthesized successfully, and the relationships between the crystal structures and the thermophysical properties were investigated by various methods. A ferroelastic domain existed in the m-Yb(Ta x Nb 1- x )O 4 ceramics, as observed by a scanning electron microscopy, which suggests that a ferroelastic phase transition occurred. The minimum thermal conductivity of the Yb(Ta x Nb 1− x )O 4 ceramics was 1.49 W m −1 ·K −1 , whereas the maximum thermal expansion coefficient (TEC) was 10.6 × 10 −6 K −1 (1200 °C). The m-phase had a lower Young's modulus (110–132 GPa) than the m′-phase (133–140 GPa). In view of the low thermal conductivity and high TEC, Yb(Ta x Nb 1− x )O 4 ceramics have the potential to be high-temperature structural ceramics .
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2020
·
IF 6.155
Heng Chen
Ytterbium aluminum garnet (Yb 3 Al 5 O 12 ) is considered as a promising thermal barrier material. However, the main limitations of Yb 3 Al 5 O 12 for thermal barrier applications are relative low thermal expansion coefficient and high thermal conductivity . In order to overcome these obstacles, herein, a new high entropy (Y 0.2 Yb 0.2 Lu 0.2 Eu 0.2 Er 0.2 ) 3 Al 5 O 12 ceramic was designed, and then powders and bulk were prepared through solid-state reaction method and spark plasma sintering (SPS), respectively. The thermal expansion coefficient of HE (Y 0.2 Yb 0.2 Lu 0.2 Eu 0.2 Er 0.2 ) 3 Al 5 O 12 is (8.54 ± 0.29) × 10 −6 K -1 at 673 K–1273 K, which is about 9% higher than that of Yb 3 Al 5 O 12 . The thermal conductivity of HE (Y 0.2 Yb 0.2 Lu 0.2 Eu 0.2 Er 0.2 ) 3 Al 5 O 12 ceramic is 3.81 W·m -1 K -1 at 300 K, which is about 18 % lower than that of Yb 3 Al 5 O 12 . Moreover, there is no reaction between HE (Y 0.2 Yb 0.2 Lu 0.2 Eu 0.2 Er 0.2 ) 3 Al 5 O 12 and thermally grown (TG) Al 2 O 3 even at 1600 °C. After annealing at 1590 °C for 18 h, the average grain size of HE (Y 0.2 Yb 0.2 Lu 0.2 Eu 0.2 Er 0.2 ) 3 Al 5 O 12 increases only from 1.56 μm to 2.27 μm. Close thermal expansion coefficient to TG Al 2 O 3 , low thermal conductivity, good phase stability, excellent chemical compatibility with TG Al 2 O 3 and slow grain growth rate make HE (Y 0.2 Yb 0.2 Lu 0.2 Eu 0.2 Er 0.2 ) 3 Al 5 O 12 promising for thermal barrier applications.
研究领域:
材料科学
·
热障涂层研究
✓ 已验证
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 11
·5873-5882
·
IF 3.784
Jun Wang,Fushuo Wu,Ruoan Zou,Yueshu Wu,Mengdi Gan,Jing Feng,Xiaoyu Chong
In this study, high-entropy rare-earth tantalate ceramics (Y 0.2 Ce 0.2 Sm 0.2 Gd 0.2 Dy 0.2 )TaO 4 ((5RE 0.2 )TaO 4 ) have been successfully fabricated. The possibility of formation of (5RE 0.2 )TaO 4 was verified via first-principles calculations. In addition, the phase structure, ferroelastic toughening mechanism, thermophysical, and mechanical properties were systematically investigated. The (5RE 0.2 )TaO 4 ceramics have lower phonon thermal conductivity (1.2–2.6 W·m –1 ·K –1 ) in the entire temperature range than that of RETaO 4 and YSZ. (5RE 0.2 )TaO 4 has a higher fracture toughness and lower brittleness index than YSZ. The thermal expansion coefficients of (5RE 0.2 )TaO 4 are as high as 10.3 × 10 -6 K –1 at 1200°C and Young's modulus is 66–189 GPa, and thus, (5RE 0.2 )TaO 4 possesses great potential for application in thermal barrier coatings (TBCs).
研究领域:
材料科学
·
固体力学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Lin Chen,Peng Wu,Peng Song,Jing Feng
Rare earth tantalates (La 1-X Eu X ) 3 TaO 7 ceramics are synthesized via solid-state reaction in this work. The phase structure is characterized via X-ray diffraction and Raman spectrum, when the microstructure and element distribution are detected by scanning electron microscopy and energy dispersive spectroscopy. As for various properties, (La 1-X Eu X ) 3 TaO 7 ceramics own excellent absorption for the UV light and the band gap ranges from 4.0 to 4.7 eV. The highest thermal expansion coefficients reach 10.8 × 10 −6 K −1 (1200 ℃) and the entire series of (La 1-X Eu X ) 3 TaO 7 ceramics exhibit excellent high-temperature phase stability. The minimum thermal conductivity reaches 1.04 W m −1 K −1 (500 ℃) ascribed to various phonon scattering mechanisms. The thermal radiation resistance relates to the crystal structure, which relies on the mean RE 3+ ionic radius. The results reveal that (La 1-X Eu X ) 3 TaO 7 ceramics are candidate thermal insulation materials.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Zhenghui Yang,Pingchuan Ma,Furong Li,Haiquan Guo,Chuanqing Kang,Lianxun Gao
The flexibility of organic light-emitting diode (OLED) displays highly depends on the properties of the flexible substrates. In this paper, a series of aromatic polyimides have been fabricated via the copolycondensation of pyromellitic dianhydride (PMDA), the two different rigid heterocyclic diamines, 2,5-bis(4-aminophenyl)pyrimidine (PRM) or 2,5-bis(4-aminophenyl)pyridine (PRD), and another flexible diamine, 4,4′-oxydianiline (ODA). The performance of the polyimide films could be systematically tailored by means of adjusting the main-chain rigidity, as well as the close packing and orientation of polymer chains by the formation of the intermolecular hydrogen bonds between poly(amic acid)s. The optimal results (PIb-4, PIb-5, PIc-2) showed that the polyimides were endowed with ultra-high glass transition temperature (T g ) exceeding 450 °C, low coefficient of thermal expansion (CTE) at 0–5 ppm K −1 and excellent thermal stability (T d5% = 570–590 °C). Meanwhile, all of them exhibited sufficient flexibility, the elongation at break at of 40–60%, extremely high tensile strength of 250–380 MPa and modulus of 4.1–6.1 GPa. Hence, the polyimide films should be the promising candidates for application as the polymer substrates for flexible OLED displays.
研究领域:
材料科学
·
显示技术
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2014
·Vol. 17
·期 1
·21-27
·
IF 1.508
Kuo Jiang,Songbai Liu
Graphical Metastable tetragonal (t′) ZrO 2 stabilized with 4 mol% Yb 2 O 3 sinters more slowly and has a higher resistance to destabilization than YSZ with the same composition (4 mol% Y 2 O 3 ). The improved phase stability is attributed to the slower diffusion of the smaller Yb 3+ ion in t′ phase compared to the larger Y 3+ ion. In addition, the TEC of 4 mol% Yb 2 O 3 -stabilized ZrO 2 is also found to be superior to that of YSZ, suggesting practical possibility for thermal barrier coatings.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 10
·3663
·
IF 3.748
Yunru Chen,Tao Yu,Jiang Jin,Hua Zhang
Triple perovskite has been recently developed for the intermediate temperature solid oxide fuel cell (IT-SOFC). The performance of Nd1.5Ba1.5CoFeMnO9−δ(NBCFM) cathodes for IT-SOFC is investigated in this work. The interfacial polarization resistance (RP) of NBCFM is 1.1273 Ω cm2~0.1587 Ω cm2in the range of 700–800 °C, showing good electrochemical performance. The linear thermal expansion coefficient of NBCFM is 17.40 × 10−6K−1at 40–800 °C, which is significantly higher than that of the electrolyte. In order to further improve the electrochemical performance and reduce the thermal expansion coefficient (TEC) of NBCFM, Ce0.8Sm0.2O2−δ(SDC) is mixed with NBCFM to prepare an NBCFM-xSDC composite cathode (x= 0, 10, 20, 30, 40 wt.%). The thermal expansion coefficient decreases monotonically from 17.40 × 10−6K−1to 15.25 × 10−6K−1. The surface oxygen exchange coefficient of NBCFM-xSDC at a given temperature increases from 10−4to 10−3cm s−1over thepo2range from 0.01 to 0.09 atm, exhibiting fast surface exchange kinetics. The area specific resistance (ASR) of NBCFM-30%SDC is 0.06575 Ω cm2at 800 °C, which is only 41% of the ASR value of NBCFM (0.15872 Ω cm2). The outstanding performance indicates the feasibility of NBCFM-30% SDC as an IT-SOFC cathode material. This study provides a promising strategy for designing high-performance composite cathodes for SOFCs based on triple perovskite structures.Keywords:triple perovskite structure;composite cathode;electrochemical performance;thermal expansion
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Zhaozhao Lv,Jianjun Sha,Guanzhang Lin,Jin Wang,Yongchun Guo,Shengquan Dong
In recent years, the research of hybrid composites reinforced by multiple reinforcements has received increasing attention because these composites have great potential to be tailored for various applications. In the present work, hybrid aluminum (Al) matrix composites reinforced with SiC particles and carbon fibers (SiC p -C fs /Al composites) were fabricated by the colloidal dispersion and suction filtration method. It was found that SiC p -C fs /Al composites had a dense structure and the carbon fibers and SiC particles were uniformly distributed in the Al matrix. The mechanical properties of SiC p -C fs /Al composites with different reinforcement volume fractions were investigated. The results showed that the SiC p -C fs /Al composites exhibited high tensile strength and elastic modulus (tensile strength 207 MPa and elastic modulus 92 GPa) when the volume fraction of SiC particles was 5% and the volume fraction of carbon fiber was 7%, which were significantly higher than that of SiC p /Al composites with 5% volume fraction of SiC particles (tensile strength 112 MPa and elastic modulus 80 GPa). The homogeneous distribution of carbon fibers and SiC particles in the Al matrix, which serves as co-reinforcing, is responsible for the high tensile strength and elastic modulus of SiC p -C fs /Al composites. The coefficient of thermal expansion (CTE) of SiC p /Al composites and SiC p -C fs /Al composites were measured at temperatures ranging from 25 °C and 400 °C. The results showed that the addition of carbon fibers caused the CTE of SiC p -C fs /Al composites to be much lower than that of SiC p /Al composites.
研究领域:
材料科学
·
机械工程
✓ 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）