JOURNAL OF ALLOYS AND COMPOUNDS
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2016
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IF 3.014
Shifeng Huang,Feng Gao,Qinggang Li,Xin Cheng
Samples with various ratios of AlN/Al 2 O 3 were fabricated via vacuum hot-pressing at 1700 °C under an applied pressure of 30 MPa for 90 min using Y 2 O 3 as a sintering aid. The densification process, microstructural development, and formation of AlON phase from Al 2 O 3 and AlN were investigated. Al 2 O 3 additive can improve the physical and mechanical properties , and purification of the grain boundaries. AlON are almost formed completely when the content of Al 2 O 3 is 80 vol%. The effects of composition, microstructure, and exposure time at 1400 °C on the oxidation behavior of AlN samples with different amounts of Al 2 O 3 were investigated. The sample with 80 vol% alumina has the best oxidation resistance .
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
Crystals
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2023
·Vol. 13
·期 1
·107
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IF 2.7
Shaocong He,Yehua Li,Xiao Zong,Shanghua Wu
In this work, Al2O3-AlN composite ceramics with high bending strength and thermal conductivity were fabricated by Digital Light Processing (DLP). The influence of AlN content on the rheological and cure behavior of Al2O3-AlN suspensions, as well as the microstructure, thermal conductivity, and bending strength of Al2O3-AlN ceramics, were systematically investigated. The result shows that the viscosity and cure ability of the suspensions were decreased with the increase of AlN content, which are beneficial to the spreading and printing accuracy of the suspensions. Besides, the bending strength of ceramics can be improved due to the residual stress by the introduction of AlN. Approaches were employed to minimize the formation of AlON in Al2O3-AlN ceramics by optimizing the amount of AlN and the sintering temperature. The thermal conductivity and bending strength of Al2O3-AlN ceramics were 31.72 ± 0.45 W/(m·K) and 572.73 ± 59.40 MPa, respectively, which are much higher than those of Al2O3ceramics fabricated under the same condition. Finally, complex-shaped Al2O3-AlN ceramics components have been successfully fabricated by DLP, which may provide an opportunity to broaden the application of Al2O3-AlN composite ceramics in heat dissipation components.Keywords:Al2O3-AlN composite ceramics;Digital Light Processing;mechanical properties;thermal conductivity
研究领域:
材料科学
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制造工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2020
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IF 3.83
Guanglin Nie,Yehua Li,Pengfei Sheng,Zhuo Tian,Wei Liu,Haidong Wu,Yiwang Bao,Shanghua Wu
To improve the thermal and mechanical properties of Al 2 O 3 /AlN composite ceramics, a novel heterogeneous precipitation coating (HPC) approach was introduced into the fabrication of Al 2 O 3 /AlN ceramics. For this approach, Al 2 O 3 and AlN powders were coated with a layer of amorphous Y 2 O 3 , with the coated Al 2 O 3 and AlN powders found to favor the formation of an interconnected YAG second phase along the grain boundaries. The interconnected YAG phase was designed to act as a diffusion barrier layer to minimize the detrimental interdiffusion between Al 2 O 3 and AlN particles. Compared with samples prepared by a conventional ball-milling method, the HPC Al 2 O 3 /AlN composites exhibited less AlON formation, a higher relative density, a smaller grain size and a more homogeneous microstructure. The thermal conductivity , bending strength , fracture toughness and Weibull modulus of the HPC Al 2 O 3 /AlN composite ceramics were found to reach 34.21 ± 0.34 W m −1 K −1 , 475.61 ± 21.56 MPa, 5.53 ± 0.29 MPa m 1/2 and 25.61, respectively, which are much higher than those for the Al 2 O 3 and Al 2 O 3 /AlN samples prepared by the conventional ball-milling method. These results suggest that HPC is a more effective technique for preparing Al 2 O 3 /AlN composites with enhanced thermal and mechanical properties, and is probably applicable to other composite material systems as well.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
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2023
·
IF 6.9
Jinjie Mo,Ziye Ling,Zhengguo Zhang,Xiaoming Fang
In this paper, we investigate a metal composite prepared using a one-step pressing method, where Al–Si alloy acts as the phase change materials (PCMs) and Al 2 O 3 /AlN serve as the structural support materials. The alloy formation and PCM composite preparation are synthesized in a single step. The study aims to characterize the microstructure, thermodynamic, and thermal properties of the composite material. To assess the heat storage properties of the prepared composite PCMs at temperatures higher than 600 °C, a high-temperature test system is established using a high-frequency induction heater. Additionally, we explore how to improve the issue of liquid leakage under high-temperature conditions. The results demonstrate that Al 2 O 3 and AlN (ceramic materials) exhibit excellent chemical compatibility with Al–Si composite PCMs. After sintering, the ceramic materials form a strong bond with Al–Si, effectively retaining the liquid phase of Al–Si alloy within the composite material. Consequently, the Al–Si composite PCMs do not exhibit high-temperature liquid leakage under elevated conditions. Both Al 2 O 3 /Al–Si and AlN/Al–Si composites possess favorable high temperature heat storage properties. The phase change enthalpy of Al 2 O 3 /Al–Si composite reaches 400 kJ/kg, with a thermal conductivity of 36 W/(m·K). Similarly, the AlN/Al–Si composite achieves a phase change enthalpy of 404 kJ/kg and a thermal conductivity of 43 W/(m·K). Both composites fulfill the requirements for high-temperature heat storage applications.
研究领域:
材料科学
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能源工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2021
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IF 4.527
Yuzhu Su,Junpu Wang,Xin Li,Qiqi Tang,Jing Yang,Li Lei,Yi Tian,Zhiwei Wang,Duanwei He
The in situ axial X-ray diffraction patterns of four ceramic powder samples (MgO, Al 2 O 3 , AlN , and cBN) that were compressed in a diamond anvil cell under uniaxial non-hydrostatic conditions were recorded. The microscopic deviatoric stress as a function of the pressure was determined from the X-ray diffraction peak broadening analysis: the curves increased approximately linearly with the pressure at the initial compression stage and then levelled off under further compression. Pressure-induced transparency was observed in all of the samples under compression, and the pressure at the turning point on the curves of the microscopic deviatoric stress versus pressure corresponded to the pressure at which the samples became transparent. Analysis of the microstructural features of the pressure-induced transparent samples indicated that the compression caused the grains to fracture, and the broken grains bonded with each other. We demonstrated that the ceramics’ pressure-induced transparency was a process during which the grains were squeezed and broken, the pores were close between the grains, and the broken grains were re-bonded under compression.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2023
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IF 5.7
Wenxin Du,Kailei Lu,Bing He,Xiaolan Zhou,Xu Huang,Jianqi Qi,Tiecheng Lu
In this work, transparent aluminate oxynitride (AlON) ceramic wafers were successfully fabricated by the direct non-aqueous tape casting of Al 2 O 3 /AlN slurry and the one-step reaction sintering for the first time. The reaction sintered AlON ceramic wafer exhibits high transmittance of 73.2 % at the wavelength of 1600 nm. This fabricating route realizes smooth and flexible tape without cracks or pinholes in Al 2 O 3 /AlN system and efficiently shortens the preparation cycle of transparent AlON wafers, which is a feasible way to prepare high-quality transparent AlON ceramics with large lateral sizes and thin thicknesses by reaction sintering, might also promote the application of transparent AlON ceramic wafers.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zhao Feng,Xiaolan Zhou,Pan Min,Hailong Li,Hong Liu,Yuntao Cheng
The intricate preparation process and prohibitively high manufacturing costs have long constrained the research and application of transparent ceramics. This study presents a straightforward, low-cost pressureless direct solid-state reaction sintering method, through which highly transparent AlON ceramics with optical properties comparable to those produced by conventional two-step methods were successfully fabricated. In this study, we found that AlN played a critical role in the sintering behavior of the Al 2 O 3 -AlN solid solution. The evolution of density and phase composition in the Al 2 O 3 -AlN solid solution with temperature revealed that the density reaches its maximum at ∼1250 °C, followed by a gradual decrease and eventual stabilization, which is due to volume expansion caused by the progressive formation of the AlON phase at ∼1650 °C. Before the complete phase transformation, the density of the solid solution decreased with increasing AlN content. Pure AlON phases were achieved when the Al 2 O 3 :AlN molar ratios were 9:3, 9:4, and 9:5, with similar densities. Microstructural examination and particle size distribution analysis revealed that variations in AlN content also affected the average grain size of the solid solution, demonstrating a non-monotonic trend characterized by an initial decrease (from ∼197.6 to ∼8.5 μm), a subsequent increase (to ∼135.8 μm), and a final decrease (to ∼7.3 μm). In contrast, hardness measurements demonstrated that the Vickers hardness decreased linearly with the increase of AlN content, from ∼19.5 to ∼13.2 GPa. Transmittance assessment indicated that the AlN content exerted a significant influence on the sintering temperature requisite for fabricating AlON transparent ceramics, with an increase in AlN content necessitating a correspondingly higher processing temperature. Finally, AlON ceramics with high optical transmittance of ∼82.3 % at 850 nm were achieved at temperatures of 1880 °C and 1900 °C for compositions with Al 2 O 3 to AlN ratios of 9:4 and 9:5, respectively.
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Xinran Hou,Lin Li,Shuaichong Wei,Jingde Li,Feichao Wu
The polysulfides shuttle and the uncontrolled dendrite growth remain the biggest roadblocks to the extensive application of lithium-sulfur batteries (LSBs). Herein, we propose heterogeneous Al 2 O 3 -AlN nanosheets that rooted on carbon nanofiber film as bifunctional hosts for these troubles, which are prepared by the facile ammonification of two-dimension metal-organic framework MIL-101(Al). As the sulfur host, the Al 2 O 3 -AlN nanosheets exhibit a strong synergistic effect of physicochemical anchoring and outstanding electrocatalysis on polysulfides, which is strengthened by the superiorities of heterostructure. In the meantime, the excellent conductivity and fully exposed Al, N lithiophilic sites guarantee a fast and homogeneous Li deposition, thus suppressing the dendritic growth. Accordingly, with the assistance of these distinctive heterogeneous nanosheets, LSBs provide a striking capacity of 730 mAh g −1 and an outstanding cycling stability with a narrow decay of 0.025% per cycle for 1000 cycles under 5 C, and also excellent cycle and rate properties at high sulfur loadings with a reduced electrolyte. This work offers new viewpoints of heterostructures as both cathode and anode materials for advanced LSBs.
研究领域:
材料科学
·
能源存储技术
✓ 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）