JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Kaiyun Li,Shuo Huang,Sheng Zhang,Hongyun Jin
Recently SrY 2 O 4 noteworthy the scientific attention because of its excellent high-temperature structural stability and high thermal expansion coefficient. However, the high thermal conductivity and sintering acceleration limit the application of SrY 2 O 4 in the field of thermal barrier coatings. In this work, Sr(Eu 0.2 Ho 0.2 Er 0.2 Tm 0.2 Yb 0.2 ) 2 O 4 high-entropy ceramic that identified by computational screening was prepared by the solid-state method. The results show that Sr(Eu 0.2 Ho 0.2 Er 0.2 Tm 0.2 Yb 0.2 ) 2 O 4 has high thermal expansion coefficient (11.76×10 −6 K −1 , RT–1500 °C), low thermal conductivity (1.39 W·m −1 K −1 , 1500 °C), and improved fracture toughness (1.94 ± 0.05 MPa⋅m 1/2 ). Particularly, the average grain size increases only from 3.42 μm to 10.68 μm after heat treatment at 1600 °C for 10–100 h, indicating excellent sintering resistance. Density functional theory calculations within heterojunction models further reveals the intrinsic connection between the diffusion ability of the grain boundary atoms and the sintering resistance. This strategy provides new insight for the design of sintering-resistant thermal barrier coating materials.
研究领域:
材料科学
·
计算材料学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2021
·
IF 8.067
Longkang Cong,Wei Li,Jiancheng Wang,Shengyue Gu,Shouyang Zhang
Thermal barrier coating (TBC) materials perform an increasingly important role in the thermal or chemical protection of hot components in a gas turbine. In this study, a novel high entropy hafnate (Y 0.2 Gd 0.2 Dy 0.2 Er 0.2 Yb 0.2 ) 2 Hf 2 O 7 was synthesized by solution combustion method and investigated as a potential TBC layer. The as-synthesized (Y 0.2 Gd 0.2 Dy 0.2 Er 0.2 Yb 0.2 ) 2 Hf 2 O 7 possesses a pure single disordered fluorite phase with a highly homogeneous distribution of rare earth (RE) cations, exhibiting prominent phase stability and excellent chemical compatibility with Al 2 O 3 even at 1300 °C. Moreover, (Y 0.2 Gd 0.2 Dy 0.2 Er 0.2 Yb 0.2 ) 2 Hf 2 O 7 demonstrates a more sluggish grain growth rate than Y 2 Hf 2 O 7 . The thermal conductivity of (Y 0.2 Gd 0.2 Dy 0.2 Er 0.2 Yb 0.2 ) 2 Hf 2 O 7 (0.73-0.93 W m −1 K −1 ) is smaller than those of components RE 2 Hf 2 O 7 and many high entropy TBC materials. Beside, the calculated thermal expansion coefficient (TEC) of (Y 0.2 Gd 0.2 Dy 0.2 Er 0.2 Yb 0.2 ) 2 Hf 2 O 7 (10.68 × 10 −6 /K, 1100 °C) is smaller than that of yttria-stabilized zirconia (YSZ). Based on the results of this work, (Y 0.2 Gd 0.2 Dy 0.2 Er 0.2 Yb 0.2 ) 2 Hf 2 O 7 is suitable for the next generation TBC materials with outstanding properties.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2020
·
IF 6.155
Lin Chen,Mingyu Hu,Jun Guo,Xiaoyu Chong,Jing Feng
As candidate thermal/environmental barrier coatings (T/EBCs), the structure characteristics and comprehensive properties of monoclinic-prime (m') RETaO 4 (RE = Yb, Lu, Sc) with excellent Al 2 O 3 /SiO 2 chemical compatibility are studied. Excellent thermal insulation protection will be provided by m'RETaO 4 due to their low thermal conductivity (∼1.6 W m −1 K −1 , 900 °C) and prominent thermal radiation resistance, which is much better than those of YSZ (∼2.5 W m −1 K −1 , 1000 °C) and La 2 Zr 2 O 7 (∼2.0 W m −1 K −1 , 900 °C). The thermal expansion coefficients (TECs) are 3.0–8.0 × 10 -6 K −1 (200−1200 °C), which is suitable for T/EBCs applications. Furthermore, absence of phase transition and extraordinary chemical compatibility with Al 2 O 3 /SiO 2 up to 1500 °C indicate the potential application prospect. The documented governing mechanisms of m'RETaO 4 properties will enable researchers to promote their application in the future investigation.
研究领域:
材料科学
·
工程热物理
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Yiyao Tian,Longbo Luo,Qiqi Yang,Lingjie Zhang,Ming Wang,Difeng Wu,Xu Wang,Xiangyang Liu
Low coefficient of thermal expansion (CTE) in the range of 40–400 °C is a crucial factor for polyimide (PI) films serving as the flexible substrate for display devices. The introduction of hydrogen bonds (H-bonds) is an effective method to obtain high Tg and low in-plane CTE below polyimide (PI) film. However, these H-bonds commonly exhibit low thermal stability and would be ruptured at high temperature (>300 °C), which leads to a remarkable increase of CTE. Herein, we report a strategy to improve thermal stability of H-bonds at the high temperature via intermolecular crosslinking. For neat PI, its in-situ FTIR results confirm severe dissociation of H-bonds above 300 °C, While after the crosslinking reaction, the content of strong H-bonds at 400 °C is 110% higher than that of neat PI, which indicates this intermolecular crosslinking restrains dissociation of H-bonds. Correspondingly, CTE values of crosslinked PI films at 300 o C–400 °C are sharply decreased from 33.8 ppm/K to 6.0 ppm/K. Moreover, decrease of in-plane orientation accompanying lower CTEs in crosslinked PI deviates from common rule reported in linear PIs, implying the important roles of H-bonds and crosslinking. More over, the contribution of H-bonds and crosslink to the decrease of CTE are performed by Pearson correlation analysis and the results indicate that the decrease of CTE in crosslinked PIs at low temperatures is completely attributed to confinement effect of crosslinking, but contribution of stable H-bonds becomes more prominent above 300 °C. Consequently, the obtained PI films exhibit ultra low CTE (1.9 ppm/K) at the range of 40 o C–400 °C, along with high Tg (>450 °C) exhibiting great potential for flexible-display substrates.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Jianing Guo,Runze Liu,Zichun Ding,Yuhang Wang,Jinyan Wang,Xigao Jian,Lishuai Zong
With the rapid development of 5G communication technology, it is difficult to balance the comprehensive performance of packaging substrate materials in integrated circuits. In this study, a high-temperature resistant, high-modulus phthalazinone-bearing tetrafunctional epoxy resin (TEPZ) was used to modify an industrial multi-resin (benzoxazine/bismaleimide/biphenyl epoxy resin) system to prepare a composite system. On the basis of this system, the addition of KH560 modified SiO 2 gives the system the advantage of a low coefficient of thermal expansion. The prepared compound system has excellent comprehensive properties. The TGA and DMA tests showed that the system had excellent thermal properties, with the best performing experimental group reaching 5 % heat loss temperatures of 421 °C and 462 °C in nitrogen and air test atmospheres, respectively, and the T g of the composites reaching 309 °C; mechanical tests showed that the composites had a flexural modulus of 33 GPa; the TMA test results showed that the composites' z-axis compression CTE was as low as 17 ppm/°C. We believe that this new composite system can provide new ideas for the design concept of new generation of electronic packaging substrate materials.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Dongren Cai,Nisakorn Saengprachum,Zhipeng Lin,Ting Qiu
In this study, a molecular simulation (Gaussian03) was used to analyze the chemical structure of 4-dimethylaminopyridine (DMAP) to investigate its use for the synthesis of ionic liquids (ILs). Based on DMAP, a series of new ILs was prepared and characterized by fourier transform infrared spectroscopy (FT-IR), 1 H nuclear magnetic resonance ( 1 H-NMR), thermogravimetric analysis (TGA), and differential scanning calorimeter (DSC). The density data of the studied ILs were measured from 328.15 K to 358.15 K, p = 0.101 MPa. It is shown that density decreases with an increase in the temperature and the alkyl chain length of cations. And density is also affected by the anion type. Furthermore, the volume of ions, NBO charges, and the interactions of anions and cations were calculated by Gaussian03 to explain the obtained density results. The second-order polynomial equation was adopted to correlate the relationship of density and temperature. Then, an isobaric thermal expansion coefficient , molecular volume, and lattice potential energy were obtained from the density data. Viscosity was determined from 323.15 K to 368.15 K, p = 0.101 MPa. It is determined that the viscosity of ILs decreases with an increase in the temperature but increases with an increase in the alkyl chain length of cations. The temperature dependence of viscosity was described by the Vogel-Fulcher-Tamman (VFT) model, and the activation energy of viscous flow ( E η ) was obtained. Furthermore, the decomposition temperature ( T d ), glass transition temperature ( T g ), and melting temperature ( T m ) of ILs were obtained from the results of TGA and DSC.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2013
·
IF 2.004
Fuxin Yang,Xiaopo Wang,Wei Wang,Zhigang Liu
In the present work, experimental values for the densities of primary amines (monoethanolamine and diglycolamine) in alcoholic solutions were studied at atmospheric pressure (97.57 kPa) using an Anton Paar digital vibrating U-tube densimeter (model DMA 5000 M) over the entire composition range from (283.15 to 343.15) K, along with the pure components. The alcoholic solutions investigated included methanol, ethylene glycol, and isopropanol. Excess molar volumes, thermal expansion coefficients, and excess thermal expansion coefficients were calculated using the experimental values. A Redlich–Kister type equation as a function of concentration was fitted with the excess molar volumes for representing the density values of the mixture solutions.
研究领域:
化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 39
·
IF 1.768
Xuesong Li,Jinmeng Hao,Qiyang Jiang,Jianxin Mu,Zhenhua Jiang
Novel phosphorus-containing polyhedral oligomeric silsesquioxane (POSS)/polyimides (PI) hybrid materials with low dielectric constant and low linear coefficients of thermal expansion (CTE) were prepared and characterized. The POSS/PI hybrid materials were synthesized with octa(aminopropyl)silsesquioxane (OAPS) and a series of phosphorus-containing polyamide acids(PAA). The PAAs were synthesized with bis(4-aminophenoxy) phenyl phosphine oxide (BAPPO), 4,4’-diaminodiphenyl ether (ODA) and 3,3',4,4'-biphenyl tetracarboxylic diandhydride (BPDA). The structures and properties of the hybrid materials were characterized. And the effect of the phosphorus-containing structure on the POSS/PI hybrid materials was discussed. The dielectric constants and CTE of the hybrid materials were remarkably lower than that of the unmodified POSS/PI films. The lowest values of dielectric constant and CTE could achieve as low as 2.64 (1 MHz) and 27.45 ppm/K. Besides, the hybrid materials also had excellent thermal properties. The highest 5% weight loss temperature of the hybrid materials was as high as 580°C under air. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42611.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Xuewei Luo,Lirong Luo,Xiaofeng Zhao,Huangyue Cai,Shuaishuai Duan,Chunhui Xu,Shuo Huang,Hongyun Jin,Shuen Hou
Emerging of high-entropy ceramics has brought new opportunities for designing and optimizing materials with desired properties. In the present work, high-entropy rare-earth zirconates (La 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Gd 0.2 ) 2 Zr 2 O 7 and (Yb 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Gd 0.2 ) 2 Zr 2 O 7 are designed and synthesized. Both high-entropy ceramics exhibit a single pyrochlore structure with excellent phase stability at 1600 °C. In addition, the Yb-containing system possesses a high coefficient of thermal expansion (10.52 × 10 −6 K -1 , RT∼1500 °C) and low thermal conductivity (1.003 W·m -1 K -1 , 1500 °C), as well as excellent sintering resistance. Particularly, the Yb-containing system has significantly improved fracture toughness (1.80 MPa·mm 1/2 ) when compared to that of lanthanum zirconate (1.38 MPa·mm 1/2 ), making it a promising material for thermal barrier coatings (TBCs) applications. The present work indicates that the high-entropy design can be applied for further optimization of the comprehensive properties of the TBCs materials.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yuhan Wang,Jinpeng Zhu,Gang Shao,Hailong Wang,Mingliang Li,Hongxia Lu,Rui Zhang
A new method is proposed to predict the formation of high-entropy single-phase oxide with a pyrochlore structure synthesis from non-equivalent principal elements. Based on this concepte, the La 2 B 2 O 7 (B = Zn 2+ , Mg 2+ /Ni 2+ , Ce 4+ /Zr 4+ /Hf 4+ /Sn 4+ /Ti 4+ , W 6+ , Mo 6+ ) were designed, in which high-entropy La 2 (ZnMgZrWMo) 2 O 7 , La 2 (ZnMgHfWMo) 2 O 7 and La 2 (ZnMgSnWMo) 2 O 7 pyrochlore ceramics were successfully prepared by solid-phase sintering. The microstructure of the entropy-stabilized phase was demonstrated using X-ray diffraction and elemental mapping, and the thermal properties including the thermal expansion coefficient and thermal conductivity were analyzed. The results show that La 2 (ZnMgZrWMo) 2 O 7 has a higher thermal expansion coefficient (13.9 × 10 –6 K –1 ) and lower thermal conductivity (0.8 W/m·K) than its corresponding single-components compound. In addition, La 2 B 2 O 7 (B = Zn 2+ , Mg 2+ , Zr 4+ /Hf 4+ /Sn 4+ , W 6+ , Mo 6+ ) pyrochlore high-entropy ceramics exhibit good calcium – magnesium – aluminosilicate (CMAS) resistance, the apatite protective layer generated after the reaction of La with CMAS effectively prevents further corrosion. This study suggests a novel method for predicting the formation of high-entropy single-phase oxides of pyrochlore structures and provides a new design concept for anti-CMAS corrosion materials.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 106
·期 4
·2476-2490
·
IF 4.186
Chenkai Qu,Lin Chen,Tao Su,Dongbo Li,Yuan Yang,Jing Feng
Ferroelastic YTaO 4 is a promising material for thermal barrier coatings (TBCs), and its thermal and mechanical properties can be further optimized by various methods. In this study, a ferroelastic middle-entropy ceramic Y 0.5 Gd 0.5 Ta 0.5 Nb 0.5 O 4 was synthesized by solid-phase sintering, and its microstructures and thermophysical properties were key points. We determined the contributions of phonons and photons to total thermal conductivity, and a low thermal conductivity was obtained by inhibiting high-temperature thermal radiation. The thermal expansion coefficients were improved by introducing of Nb atom into the lattice of the prepared middle-entropy ceramic, which meets the requirements of TBCs. The improved wear resistance originated from relatively high Young's modulus and the hardness of Y 0.5 Gd 0.5 Ta 0.5 Nb 0.5 O 4 , and it would contribute to the service performance of the corresponding coatings. This work motivates the engineering applications of ferroelastic RETaO 4 and RENbO 4 (RE is rare-earth element) as high-temperature TBCs.
研究领域:
材料科学
·
热力学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materiomics
·
2023
·
IF 9.4
Fangze Chen,Dacheng Zhou,Xueqing Xiong,Juntao Pan,Donglin Cai,Ze Wei,Xiyong Chen,Yihui Liu,Nengneng Luo,Jialin Yan,Toyohisa Fujita
A series of single-phase double perovskite Pr 1- x Gd x BaCo 2- y Fe y O 5+ δ ( x = 0, 0.5 and 1, 0 ≤ y ≤ 1) materials were engineered through A/B site co-doping strategy to improve the mechanical, electrical and electrochemical properties as potential cathode materials for the application of intermediate solid oxide fuel cells (IT-SOFCs). The corresponding thermochemical stability, thermal expansion behavior, electrical conductivity and cathodic polarization resistance of the materials were systematically investigated. It was found that the A-site dual lanthanide doped Pr 0.5 Gd 0.5 BaCo 2 O 5+ δ (PGBCO) exhibits improved electrical conductivity, reduced thermal expansion, and comparatively low electrochemical polarization resistance versus single lanthanide double perovskite, PrBaCo 2 O 5+ δ (PBCO) and GdBaCo 2 O 5+ δ (GBCO) materials. Further investigation on the effect of B-site Fe-doping on Pr 0.5 Gd 0.5 BaCo 2- y Fe y O 5+ δ (PGBCF- y , 0 ≤ y ≤ 1) reveals that all the PGBCF- y compositions exhibit excellent chemical stability with Gd-doped ceria (GDC) at operating temperatures not higher than 1 100 °C. Besides, doping of Fe in B-site can effectively reduce the thermal expansion coefficients (TECs) of the Pr 0.5 Gd 0.5 BaCo 2 O 5+ δ ceramics at 30–1 000 °C. And the electrochemical impedance spectra (EIS) results show that the PGBCF- y |GDC| PGBCF- y symmetric cells have acceptable low area specific polarization resistances. Further examination of the cathodic polarization and characteristic capacitance from the AC impedance spectra by employing the relaxation time distribution (DRT) method demonstrated that charge transfer is the dominating sub-process for the oxygen transport through the materials.
研究领域:
材料科学
·
燃料电池研究
✓ 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）