CERAMICS INTERNATIONAL
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2024
·
IF 5.1
Bo Wang,Ziyan Zhao,Zihao Pan,Xuejian Liu,Zhengren Huang,Yan Liu
The ZnO–Al 2 O 3 –B 2 O 3 –SiO 2 (ZABS) glass powder was designed and innovatively employed to join AlN ceramics. The crystallization, thermal expansion and wettability behavior of the ZABS glass and glass-ceramic were investigated. The results shows that Zn 3 B 2 O 6 , ZnSiO 4 and Zn 4 B 6 O 13 were precipitated after heat treatments at different temperature, respectively, resulting in a variation in the coefficient of thermal expansion (CTE) of the ZABS glass ceramic. Then guided by the wetting behavior on the AlN ceramic substrate, the joining of the AlN ceramics by ZABS glass at various temperatures and holding times were conducted. Notably, Zn 3 B 2 O 6 was identified to be the primary product in the joints bonded at temperature of 700–800 °C due to the crystallization within the glass and no discernible reaction was observed between the substrate and the interlayer, while ZnSiO 4 was observed at the periphery of Zn 3 B 2 O 6 after 750 °C. Moreover, the crystalline phase Zn 3 B 2 O 6 gradually grew with the temperature and holding time increasing as the glassy phase gradually diminished, resulting in a reduction of the strength and reliability of the joints. The optimal flexural strength of the joints was 156 ± 11MPa at 700 °C for 30min. The reason for the high strength can be attributed to the interactions between the glass precipitated crystalline phase interlocking each other and the glass phase tightly bonded with the crystalline phase.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Junji Wei,Hao Wang,Zongwu Zhang,Zexing Zhang,Runlin Lu
High-temperature thermosetting resin with low dielectric constant ( κ ), low thermal expansion coefficient (CTE), and high modulus are drawing more and more attention from scientists and engineers in the field of the high-frequency circuit, 5G and 6G communication networks to improve the signal transmission speed. Epoxy resin, as one of the important thermosetting resin members, possesses excellent properties such as heat resistance, cohesiveness, and reactivity. However, Epoxy resin was usually mixed with different inorganic fillers to meet the above requirements, especially to decrease the κ and CTE. In this work, a new class of spirobisindane epoxy resin monomer (TSDEP) was synthesized by a classic two-step method based on 3,3,3′,3′-tetramethyl-1,1′-spirobisindane-6,6′-diol (TSD). Due to the highly distorted rigid structure of TSD, the movement of the TSDEP molecular segment is subject to more restrictions after being cured, and the free volume will increase. After cured by 4,4′-diamino diphenyl sulfone (DDS), the TSDEP/DDS resin exhibited many desirable physical properties, e.g., low dielectric constant (∼3.45, 1 MHz), low dielectric loss (∼0.025, 1 MHz), low coefficient of thermal expansion (CTE, 72 ppm/ °C, 35–150 °C), high glass transition temperature ( T g > 241 °C) and high thermal stability ( T d5% ∼400 °C). Furthermore, TSDEP/DDS exhibited excellent mechanical rigidity with a storage modulus of ∼ 3.1 GPa. Compared with TSDEP/DDS, 4-methylhexahydrophthalic anhydride (MHHPA) cured TSDEP system showed lower κ (∼3.09) and dielectric loss (0.015) due to weaker polar ester groups instead of more polar hydroxy groups.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2021
·Vol. 59
·期 6
·510-518
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IF 0
Guangtao Qian,Fengna Dai,Haiquan Chen,Mengxia Wang,Mengjie Hu,Chunhai Chen,Youhai Yu
Three novel diamines, incorporating benzimidazole and amide moieties, namely 4-amino-N-(5-amino-benzimidazol-2-yl)-benzamide (6a), 4-amino-N-(5-amino-1- methyl-benzimidazol-2-yl)-benzamide (6b), and 4-amino-N-(5-amino-1-phenyl -benzimidazol-2-yl)-benzamide (6c), were designed and synthesized. A series of poly(benzimidazole-amide-imide) (PBIAI) films were prepared from the resulting diamines and 4,4-biphthalic dianhydride (BPDA). These flexible polyimides (PIs) showed high glass transition temperatures ( T g = 353–379°C), low coefficients of thermal expansion (CTE = 3.7–12.3 ppm K −1 ) and good mechanical properties ( σ = 152–207 MPa and E = 4.5–7.7 GPa), promising candidates for applications in flexible-display substrates. Furthermore, the data guided a feasible method to enhance T g and reduce CTE by introducing benzimidazole and amide units into PI main chains, and the effect of different N-substituents on performance was revealed. Graphical
研究领域:
材料科学
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高分子化学
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DOI
Journal of Materials Research and Technology-JMR&T
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2020
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IF 5.289
Chenguang Liu,Liming Yu,Zongqing Ma,Yongchang Liu,Chenxi Liu,Huijun Li,Hui Wang
Effects of Y 2 W 3 O 12 particle inclusions and content on damping capacity of Al–12Si composites have been investigated. The Y 2 W 3 O 12 , which is a kind of negative thermal expansion material, can generate high local strain in the composites. Thermal expansion testing shows that the coefficient of thermal expansion (CTE) of Y 2 W 3 O 12 has obvious changes between 100 and 200 °C The Y 2 W 3 O 12 /Al–12Si composites show damping peaks and display higher damping capacities than the pure Al–12Si alloy. The damping capacities of composites strongly depends on the content of Y 2 W 3 O 12 inclusions. A thermal strain damping model is also established. Based on the model analysis results, there is a significant contribution of thermal strain to the damping capacity in the composites; the change in CTE of Y 2 W 3 O 12 could cause the generation of damping peaks. Moreover, dislocation damping and interfacial damping are also main damping mechanisms in the investigated composites.
研究领域:
材料科学
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力学
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2019
·Vol. 103
·期 4
·2727-2740
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IF 3.094
Fushuo Wu,Peng Wu,Yunxuan Zhou,Xiaoyu Chong,Jing Feng
In this work, RENbO 4 (RE = Y, La, Nd, Sm, Gd, Dy, Yb) ceramics with low density, low Young's modulus, low thermal conductivity, and high thermal expansion have been systematically investigated, the excellent thermo-mechanical properties indicate that RENbO 4 ceramics possess the potential as the new generation of thermal barrier coatings (TBCs) materials. X-ray diffraction and Raman spectroscopy phase structure identification reveal that all dense bulk specimens obtained by high-temperature solid-state reaction belonged to the monoclinic (m) phase with C12/c1 space group. The ferroelastic domains are detected in the specimens, revealing the ferroelastic transformation between tetragonal (t) and monoclinic (m) phases of RENbO 4 ceramics. The Young's modulus and hardness of the RENbO 4 ceramics measured by the NanoBlitz 3D nanoindentation method are discussed in details, and the lower Young's modulus (60-170 GPa) and higher hardness (the maximum value reaches 11.48 GPa) indicating that higher resistance of RENbO 4 ceramics to failure and damage. Lower thermal conductivity (1.42-2.21 W [m k] −1 at 500°C-900°C) and lower density (5.330-7.400 g/cm 3 ) than other typical TBCs materials give RENbO 4 ceramics the unique advantage of being new TBCs materials. Meanwhile, the thermal expansion coefficients of RENbO 4 ceramics reach 9.8-11.6 × 10 −6 k −1 and are comparable or higher than other typical TBCs materials. According to the first-order derivative of the thermal expansion rate, the temperature of the ferroelastic transformation of RENbO 4 ceramics can be observed.
研究领域:
材料科学
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固体力学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2020
·
IF 6.155
Zifan Zhao,Heng Chen,Huimin Xiang,Fu-Zhi Dai,Xiaohui Wang,Wei Xu,Kuang Sun,Zhijian Peng,Yanchun Zhou
Yttrium aluminum perovskite (YAlO 3 ) is a promising candidate material for environmental barrier coatings (EBCs) to protect Al 2 O 3f /Al 2 O 3 ceramic matrix composites (CMCs) from the corrosion of high-temperature water vapor in combustion environments. Nevertheless, the relatively high thermal conductivity is a notable drawback of YAlO 3 for environmental barrier coating application. Herein, in order to make RE AlO 3 more thermal insulating, a novel high-entropy rare-earth aluminate ceramic (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Er 0.2 )AlO 3 was designed and synthesized. The as-prepared (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Er 0.2 )AlO 3 ceramic possesses close thermal expansion coefficient (9.02 × 10 ―6 / o C measured from room temperature to 1200 °C) to that of Al 2 O 3 . The thermal conductivity of (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Er 0.2 ) AlO 3 at room temperature is 4.1 W·m −1 K −1 , which is almost one third of the value of YAlO 3 . Furthermore, to effectively prevent the penetration of water vapor from possible pores/cracks of coating layer, which are often observed in T/EBCs, a tri-layer EBC system RE AlO 3 / RE 3 Al 5 O 12 /(Al 2 O 3f /Al 2 O 3 CMCs) is designed. Close thermal expansion coefficient to Al 2 O 3 and low thermal conductivity of (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Er 0.2 )AlO 3 , as well as the formation of dense garnet layer at (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Er 0.2 )AlO 3 /Al 2 O 3 interface, indicate that this new type of high-entropy ceramic is suitable as a candidate environmental barrier coating material for Al 2 O 3f /Al 2 O 3 CMCs.
研究领域:
材料科学
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航空航天工程
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产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 80
·42737-42746
·
IF 3.708
Seongku Kim,Xingyuan Wang,Shinji Ando,Xiaogong Wang
Based on a hydroxyl-terminated hyperbranched polyimide (HBPIBPADA-TAP(OH)), two series of hybrid ternary composites composed of a linear polyimide (PI6FDA-APB), HBPIBPADA-TAP(OH) (10% and 20%), and various concentrations of SiO2 were fabricated by sol–gel method. Research showed that properties of the composites are closely related with the ratio of HBPIBPADA-TAP(OH) to SiO2, which can be optimized by proper choice of the compositions. Under optimized conditions, the hybrid ternary composites show properties complementary to the drawbacks of unary or binary systems. The dielectric constant (Dk) of the PI6FDA-APB_HBPIBPADA-TAP(OH)-10%_SiO2-10% composite reaches the lowest value of 2.26. The silica loading and reinforcement binding with PI6FDA-APB_HBPIBPADA-TAP(OH) matrix are confirmed by the SEM morphology of the hybrid ternary composite films. When a suitable amount (20%) of HBPIBPADA-TAP(OH) is added into the PI6FDA-APB_SiO2-10% composite, the optical transmittance is significantly improved to be 63% at the wavelength of 450 nm. With increase in the content of SiO2, the thermal expansion is obviously reduced. For the PI6FDA-APB_HBPIBPADA-TAP(OH)-10%_SiO2-30% composite, the coefficient of thermal expansion (CTE) of the film is reduced to 15.9 ppm °C−1 compared to 37.1 ppm °C−1 for the PI6FDA-APB film (reducing about 59%). Due to these optimized properties, hybrid ternary composite films are expected to have potential applications in micro-electronic insulator fields such as interlayer dielectric of advanced electronic devices.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2018
·
IF 3.794
Jinshuang Wang,Junbin Sun,Qiangshan Jing,Bing Liu,Hao Zhang,Yu Yongsheng,Jieyan Yuan,Shujuan Dong,Xin Zhou,Xueqiang Cao
The properties of ZrO 2 co-stabilized by CeO 2 and TiO 2 ceramic bulks were investigated for potential thermal barrier coating (TBC) applications. Results showed that the (Ce 0.15 Ti x )Zr 0.85-x O7 (x = 0.05, 0.10, 0.15) compositions with single tetragonal phase were more stable than the traditional 8YSZ at 1573 K. These compositions also showed a large thermal expansion coefficient (TEC) and a high fracture toughness, which were comparable to those of YSZ. However, the phase stability, fracture toughness and sintering resistance of the CeO 2 -TiO 2 -ZrO 2 system showed a decline tendency with the increase of TiO 2 content. The TEC of the ceramic bulks decreased with increase of TiO 2 content as well because the crystal energy was enhanced with increasing substitution of Zr 4+ by smaller Ti 4+ . The (Ce 0.15 Ti 0.05 )Zr 0.8 O 2 had the best comprehensive properties among the (Ce 0.15 Ti x )Zr 0.85-x O 2 compositions as well as a low thermal conductivity . Therefore, it can be explored as a TBC candidate material for high-temperature applications.
研究领域:
材料科学
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热力学工程
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产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2016
·
IF 2.101
XinWei Shi,Hong Lian,XiaoSheng Yan,Ruiqiong Qi,Ning Yao,Tao Li
Negative thermal expansion Zr 2 WP 2 O 12 (ZWP) powder prepared by hydrothermal method was used as fillers to tailor the thermal expansion coefficient (TEC) of the polyimide (PI)-based composites. A series of PI-based composites containing different loading (0–40 wt% or 0–19.6 vol%) of ZWP powder were fabricated by the in-situ polymerization technique. Their structures and properties were characterized by Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Impedance meter, Thermal mechanical analysis (TMA) and Thermogravimetric analysis (TGA). The additions of ZWP steadily reduced the TEC of the PI matrix at all loadings studied. A 40 wt% (19.6 vol%) ZWP loading gives a 32.5% (about 15 × 10 −6 /K) reduction of TEC. The thermal stability of the ZWP/PI composites can be enhanced with the increment of ZWP powder. The independence of the dielectric constant on frequency is improved by introduction of ZWP particles to PIs. The dielectric loss displays good stability, which indicates that the ZWP/PI composites show potential applications in microelectronic and aerospace industries .
研究领域:
材料科学
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复合材料
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热力学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Shuai Gao,Nan Zhao,Qinqin Liu,Yi Li,Guifang Xu,Xiaonong Cheng,Juan Yang
Owing to that, efficient cooling the chip demands a heat sink material possess high thermal conductivity and low CTE equivalent to the gallium arsenide (GaAs) or silicon (Si). Addressing this target, we have synthesized Sc 2 W 3 O 12 /Cu composites by hot-pressing sintering at 700 °C, which was based on the uniform submicron Sc 2 W 3 O 12 powder prepared for the first time. The resulting product not only possessed a low CTE (8.31 ppm/K, which was identical to GaAs of 6.2 ppm/K) and high thermal conductivity (243.99 W/m K), but also exhibited extremely stable CTE within a temperature range of 25 °C–300 °C and high Vickers hardness (234.32 HV) due to its uniform and nearly full dense microstructure. A ‘thermoelastic-micro-mechanics'model was used to predict the CTE quantitatively and the estimated values were in good agreement with the experimental CTE values. Moreover, the excellent compatibility of thermal properties between Sc 2 W 3 O 12 and Cu possesses an isolated spot in Ashby map based on CTE and thermal conductivity, and the as-synthesized composite exhibits nearly greatest thermal stability indicated via its low thermal distortion parameter (TDP).
研究领域:
材料科学
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热管理技术
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 37
·5364-5376
·
IF 5.582
Zhenghui Yang,Haiquan Guo,Chuanqing Kang,Lianxun Gao
Three novel dianhydride monomers involving amide groups were synthesized and further polymerized with various diamines to afford a series of colorless polyimides (cPI). The resultant cPI films present outstanding optical performance, exceedingly good dimensional stability at high temperature, great film ductility and solution-processability. In particular, chemically imidized AMDA/TFDB has an ultra-low coefficient of thermal expansion value of 5.2 ppm K−A, a relatively high Tg value of 333 °C and large elongation at break of 29%, resulting from its rigid-rod backbone and the formation of hydrogen bonding (–CO⋯NH–) between adjacent molecular chains. Concurrently, it exhibits a high optical transmittance of 87% at a wavelength of 550 nm, a small haze value of 0.71 and low yellow index of 4.29 by reason that the incorporation of bulky trifluoromethyl and cyclohexyl preclude the formation of a charge transfer complex effectively. The high overall performance of the amide-containing cPI films suggests its potential application in the field of flexible OLED displays.
研究领域:
材料科学
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显示技术
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产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2021
·
IF 3.531
Leibo Deng,Zhe Fu,Zhang Mingxing,Hao Li,Bin Yao,Jianli He,Hua Chen,Yonghong Ma
TiO 2 –ZrO 2 -codoped MgO–B 2 O 3 –Al 2 O 3 –SiO 2 glass-ceramics were prepared using the traditional melting method. The effects of replacing TiO 2 with ZrO 2 on the glass stability (GS), crystallization behavior, structures, and properties of the obtained samples were studied. Results showed that the addition of ZrO 2 increased the GS, which decreased the crystallization ability of the samples. When the heat treatment temperature was increased from 900 °C to 1000 °C, the mullite and quartz phases first precipitated in the glass matrix, and then converted into cordierite. Because of the low solubility of TiO 2 and ZrO 2 in this glass system, the rutile and zircon phases will precipitate from the parent glasses. Owing to changes in the composition and structure of the samples, the density and Vickers hardness increased, while the coefficient of thermal expansion of the samples first decreased and then increased when TiO 2 was replaced with ZrO 2 .
研究领域:
材料科学
·
无机非金属材料
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）