JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Sheng Li,Junjie Shi,Yuchao Qiu,Yongyi Zhou,Xiaoyu Gong,Hongjian Tang,Dong Li,Xiao Sai,Jianzhang Li
Phase relationships in the Yb 2 O 3 –Al 2 O 3 –SiO 2 system are critical for the design and corrosion protection of environmental barrier coatings (EBCs), the available data remain scarce and primarily limited to studies from the 1990s. The isothermal phase diagram of the Yb 2 O 3 –Al 2 O 3 –SiO 2 system at 1600°C was conducted using a classical high-temperature equilibrium quenching technique, followed by XRD, SEM, and EPMA phase analysis. The data were reported in the form of liquidus projections and an isothermal phase diagram at 1600°C, with one single-phase region, six two-phase regions, and seven three-phase regions. A comparison of the liquid phase regions at 1550°C and 1600°C revealed a systematic expansion with increasing temperature, consistent with thermodynamic expectations. The experimental results from the present work are essential for the development of a thermodynamic database for rare earth oxides, providing vital guidance for designing next-generation EBCs.
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·Vol. 109
·期 1
·e70416
·
IF 3.8
Junjie Shi,Sheng Li,Chenglin Kang,Futong Li,Min Chen,Shizhuo Yin,Jianzhong Li
This study presents the first systematic experimental determination of phase equilibria in the Er 2 O 3 –Al 2 O 3 –SiO 2 system at 1600°C in air, employing the high-temperature isothermal equilibration method followed by rapid drop-quenching to preserve high-temperature phase assemblages. The mineralogy and chemical compositions of the equilibrated samples were analyzed by x-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe x-ray microanalysis (EPMA). One single liquid equilibria, five two-phase equilibria (liquid–SiO 2 , liquid–Er 2 Si 2 O 7 , liquid–Er 3 Al 5 O 12 , liquid–Al 2 O 3 , and liquid–mullite) and seven three-phase equilibria (liquid–SiO 2 –Er 2 Si 2 O 7 , liquid–Er 2 Si 2 O 7 –Er 2 SiO 5 , liquid–Er 2 SiO 5 –Er 3 Al 5 O 12 , liquid–Er 3 Al 5 O 12 –Al 2 O 3 , liquid–Al 2 O 3 –mullite, Er 2 O 3 –Er 2 SiO 5 –Er 4 Al 2 O 9 , Er 3 Al 5 O 12 –Er 2 SiO 5 –Er 4 Al 2 O 9 ) were observed in the equilibrium ternary system. The 1600°C isothermal section of the Er 2 O 3 –Al 2 O 3 –SiO 2 phase diagram in air ( p O 2 = 0.21 atm) was constructed based on the present experimentally determined equilibrium phase compositions. The liquid area and the primary fields of SiO 2 , Er 2 Si 2 O 7 , Er 3 Al 5 O 12 , Al 2 O 3 , and mullite were constructed. The comparison of the present experimental results deviate significantly from the modelling by FactSage (version 8.3) using its “ FactPS ” and “ FToxid ” databases, suggesting that FactSage underestimated the stability of the liquid phase under the present experimental conductions.
研究领域:
材料科学
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陶瓷
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相图
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高温材料
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腐蚀科学
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热力学
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高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Sheng Li,Chaoqi Zhao,Rui Zhang,Junjie Shi,Yuyan Wu,Xiao Zhang,Chuan Wang,Shizhuo Yin,Yandong Li,Jianzhong Li
The Ho 2 O 3 -Al 2 O 3 -SiO 2 system exhibits great application potential for advanced environmental barrier coatings and multifunctional materials, whereas critical high-temperature phase equilibrium data remain scarce. In this work, the 1600 °C isothermal section of the ternary system was systematically constructed using equilibration and quenching experiments, combined with X-ray diffractometry (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and differential scanning calorimetry (DSC). Crucially, the thermodynamic stability of the Ho 2 Si 2 O 7 phase at 1600 °C and above is confirmed, refining the previously reported Ho 2 O 3 -SiO 2 binary phase diagram. At 1600 °C, the Ho 2 O 3 -Al 2 O 3 -SiO 2 system comprises one liquid-phase region, eleven two-phase regions, and nine three-phase regions. The eutectic temperature of the system was measured to be 1359 °C, corresponding to the reaction L ⇋ SiO 2 + Ho 2 Si 3 O 9 + mullite. The solid-solution mechanisms were determined for the two phases Ho 9.33+2 x (Si 1- x Al x O 4 ) 6 O 2 ( x = 0-0.09) and Ho 4 Al 2(1- x ) Si 2 x O 9+ x ( x = 0-0.33). Comparison with FactSage 8.3 calculations reveals that current commercial databases exhibit significant deficiencies for the Ho 2 O 3 -SiO 2 binary system. This study further improves the thermodynamic database of rare-earth oxides. The findings not only provide key data for optimizing CALPHAD thermodynamic models, but also offer an important basis for the composition design and phase regulation of environmental barrier coatings intended for extreme environments.
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高影响因子
CATALYSIS LETTERS
·
2026
·Vol. 156
·期 9
·242
·
IF 2.5
Shi Guopu,Shi Fangxu,Liang Fuxin,Wei Yulin,Li Yuanguang,Han Yubing,Wu Junyan,Huang Sai,Wang Honglei,Ji Jun,Wu Chao
Ethyl 3-piperidine-carboxylate is an important intermediate in the pharmaceutical field. To break through the limitations of poor mechanical strength and thermal stability of catalysts and low catalytic efficiency of foam ceramic carriers due to the lack of active sites in traditional synthesis, this study used the hydrogenation synthesis of ethyl nicotinate to produce this intermediate as the probe reaction. Pd-Ni/Ru-Al 2 O 3 -SiO 2 foam ceramic catalysts were prepared by the sol-gel method and the impregnation method. Relying on the bimetallic differentiated synergistic effect of Ni, Ru, and Pd, the above technical bottlenecks were overcome. A variety of characterization techniques reveal its core mechanism of action: Pd serves as the catalytic core, and Ni can optimize the electronic structure, enabling the Pd-Ni alloy to obtain the optimal d-band center and adsorption energy, laying an electronic foundation for efficient catalysis. Ru can precisely control the particle size of Pd-Ru alloy, which is 4.5 nm smaller than that of single-metal Pd, significantly improving the metal dispersion and the utilization rate of active sites. The three-dimensional network structure of foam ceramics enhances mass transfer efficiency. The γ-Al 2 O 3 -SiO 2 coating provides abundant active sites and excellent stability. The catalytic performance of this system has been significantly enhanced. Among them, the yield of the corresponding product of the Pd-Ni bimetallic catalyst reached 92.57%, and it still remained above 80% after five cycles of use, providing new prospects for the green and efficient synthesis of ethyl 3-piperidine-carboxylic acid esters and the development of low-cost hydrogenation catalysts. Graphical
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高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jing Chang,Xukun Yang,Yifan Li,Shuai Chen,Qinyin Xu,Yixin Zhang,Liwen Yan
Mullite fiber felt with outstanding thermal stability and excellent thermal insulation performance was widely used as a thermal protection material in the aerospace field. However, the poor mechanical property severely restricted the application of mullite fiber felt. Herein, the mullite fiber felt reinforced Al 2 O 3 -SiO 2 (MF/Al 2 O 3 -SiO 2 ) porous composites with lamellar matrix were fabricated by the sol impregnation combined with the freeze-drying method. Compared to the ambient-dried MF/Al 2 O 3 -SiO 2 composites, freeze-dried MF/Al 2 O 3 -SiO 2 composites with lamellar matrix possessed a lower density (0.32–0.86 g/cm 3 ), higher porosity (73.30–90.03 %) and lower thermal conductivity (0.12–0.22 W m −1 K −1 ). What’s more, due to the dense lamellar Al 2 O 3 -SiO 2 ceramic matrix, the compressive strength of freeze-dried MF/Al 2 O 3 -SiO 2 composites was nearly 4 times higher than that of ambient-dried MF/Al 2 O 3 -SiO 2 composites and up to 4.25 MPa. In addition, the thermal and mechanical properties of MF/Al 2 O 3 -SiO 2 composites were maintained well at 1400 °C. The improved thermal insulation and mechanical properties of MF/Al 2 O 3 -SiO 2 porous composites with lamellar matrix indicated that MF/Al 2 O 3 -SiO 2 porous composites could be a promising candidate as the high-temperature thermal protection material in the aerospace field.
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高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zhuoqing An,Yuan Gao,Jiajing Chen
The CaO-MgO-Al 2 O 3 -SiO 2 (CMAS) glass-ceramics containing complex nucleation agents including La 2 O 3 and Fe 2 O 3 were prepared by melt process. The effects of these complex nucleation agents on the crystallization and microstructure of CMAS glass-ceramics were investigated through the thermal analysis (DSC), X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM) and Raman spectroscopy. The results indicated that the addition of La 2 O 3 and Fe 2 O 3 decreases viscosity and ion movement resistance. Furthermore, the La 2 O 3 can increase the crystallization peak temperature, while the Fe 2 O 3 has an inverse effect. The crystallization activation energy decreased from 298.87 to 264.26 kJ/mol as the mole ratio of La 2 O 3 increased to 2%. Conversely, when the mole ratio of Fe 2 O 3 increased to 2%, the crystallization activation energy increased from 298.87 to 347.21 kJ/mol. However, the addition of La 2 O 3 and Fe 2 O 3 decreased the Avrami parameter and promoted the surface crystallization within the CMAS glass system, as confirmed by the microstructure analysis. The crystal show branch-like crystal morphology when La 2 O 3 adding, whereas Fe 2 O 3 addition led to a compact, seaweed-like morphology with a fractal structure. With decreasing La 2 O 3 and increasing Fe 2 O 3 , the width of the dendritic branches increased. The major crystal phases detected on the surface were augite and diopside phase. Fe is predominantly present in the augite phase and La is primarily incorporated as a solid solution within the crystal phase.
研究领域:
材料科学
·
化学
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高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Leibo Deng,Tianyi Li,Yahui Zhou,Wenjing Zhang
The harmless treatment of Cr-containing solid waste remains a critical environmental challenge. Herein, Cr 2 O 3 -doped CaO–MgO–Al 2 O 3 –SiO 2 glass-ceramics with varying Na 2 O contents were prepared via a melting method. The study focuses on how Na 2 O regulates the glass network, crystallization behavior, and Cr immobilization efficiency. With increasing Na 2 O content, the degree of depolymerization (DOD) of the parent glass increases from 1.76 to 1.99, while the crystallization activation energy decreases accordingly. The optimal formulation is achieved at 1 wt% Na 2 O combined with a two-stage heat treatment (nucleation at 720 °C for 2 h, followed by crystallization at 850 °C for 2 h). Under these conditions, the glass-ceramic exhibits the lowest Cr leaching concentration of 0.031 mg/L, far below the regulatory limit of 5 mg/L. The dominant crystalline phases are diopside and a spinel solid solution, where Cr 3+ is stably incorporated into the spinel. These findings demonstrate that controlled Na 2 O addition provides an effective compositional lever for optimizing both crystallization kinetics and heavy metal immobilization, offering a sustainable pathway for valorizing Cr-containing wastes into high-performance glass-ceramics.
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高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Jiachen Chen,Jin Li,Beining Li,Zhuocheng Chen,Xue Bai,Long Zhang,Jin He
The development of advanced luminescent materials is highly desirable for developing the energy-efficient lighting technology. However, it is still challenging to achieve stable full-color tuning in the same matrix upon a single-beam light excitation so as to ensure the high color stability and consistency. Herein, Eu 3+ /Eu 2+ /Tb 3+ co-doped sintered nanoporous glass via the dipping strategy is fabricated, which can emit blue, green and red emissions simultaneously by simply modifying the thermal treatment temperature. This full-color tuning is attributed to the dual roles of the thermal reduction of Eu 3+ to Eu 2+ in Al 2 O 3 -SiO 2 glass and simultaneous emissions of Eu 3+ /Eu 2+ /Tb 3+ activators. The densification of nanoporous glass via sintering could effectively decrease the amount of hydroxyl groups that present in the glass matrix, resulting in 5 times enhancement of the photoluminescence intensity and longer photoluminescence lifetime of rare earth (RE) ions. The thermal reduction of Eu 3+ to Eu 2+ is due to the reduction environment provided by Al 3+ ions in the Al 2 O 3 -SiO 2 glass. The energy transfer (ET) from Eu 2+ to Tb 3+ , Eu 2+ to Eu 3+ and Tb 3+ to Eu 3+ have been investigated in detail. Based on the ET mechanism, rational PL spectra design was demonstrated by varying the concentration of Eu 3+ ions in solution. The Color Correlated Temperature (CCT) and the Color Rendered Index (CRI) values of the white light emission glass are 7420 K (Cold-white emission) and 80.85, the temperature dependent photoluminescence (TDPL) analysis reflects the white light emission glass possesses high thermal stability and excellent thermal restorability. This facile fabrication and full-color tuning of Eu 3+ /Eu 2+ /Tb 3+ co-doped sintered nanoporous Al 2 O 3 -SiO 2 glass may provide a novel luminescent material for white-light emitting diodes (WLEDs) application.
研究领域:
材料科学
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光学工程
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高影响因子
REFRACTORIES AND INDUSTRIAL CERAMICS
·
2023
·
IF 0.5
Ding Donghai,Guan Yue,Xiao Guoqing,Mao Zhaoyuan,Shi Xiaoqi,Gao Kaiqiang,Chong Xiaochuan,Luo Jiyuan,Lei Changkun
The alumina ceramics with high compressive strength were prepared by pressureless sintering, and the kaolinite and calcium carbonate were added as Al 2 O 3 –SiO 2 –CaO sintering aids. The effects of sintering temperature on the volume shrinkage, bulk density, water absorption and compressive strength of the alumina ceramics were studied. The phase composition, crystal cell parameters, average grain size and microstructure of the ceramic were analyzed by XRD, SEM and EDS. The results show that the lattice tends to packed with the increase of sintering temperature. The bonding between grains is the most compact after sintering at 1700°C. The volume shrinkage increases with the increase of sintering temperature. The water absorption of alumina ceramics after sintering at 1700°C reaches the minimum value of 0.06%. The bulk density and compressive strength increase first and then decrease with the increase of sintering temperature. At 1700°C, optimized mechanical properties of alumina ceramics is obtained, with a bulk density of 3.80 g/cm 3 and a compressive strength of 1323 MPa.
研究领域:
材料科学
·
陶瓷工程
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DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2024
·
IF 3.9
Lihan Deng,Jin Li,Jiachen Chen,Jin He
Nanoporous Al 2 O 3 -SiO 2 glasses were prepared using a sol–gel method. These sintered nanoporous Al 2 O 3 -SiO 2 glasses have a transmittance greater than 85 % and possess high mechanical strength, enabling them to contain and protect RE ions. Owing to the presence of nanopores in nanoporous Al 2 O 3 -SiO 2 glasses, Eu ions can easily enter the nanoporous Al 2 O 3 -SiO 2 glasses via an ex-situ dipping method. After drying at room temperature (RT) and then heating at 400 °C, 600 °C, 800 °C, and 1200 °C, we obtained a series of Eu doped nanoporous Al 2 O 3 -SiO 2 glasses. The thermal reduction process from Eu 3+ ions to Eu 2+ ions can occur at a lower sintering temperature (400 °C), enabling a detailed analysis of the thermal reduction mechanism at both low and high temperatures in detail. Under the conditions where Al 3+ ions are present in the samples that are under calcination, Eu 2+ -doped nanoporous Al 2 O 3 -SiO 2 glasses are more easily obtained at relatively low temperatures. Owing to the adjustable composition of Eu 3+ /Eu 2+ in the nanoporous Al 2 O 3 -SiO 2 glasses, tunable emission from red-orange light to blue-violet light can be achieved in the samples. This new type of transparent Eu-doped NPGs has the advantages of high mechanical strength and good processability and is non-toxic and harmless, thereby showing great potential for use in tunable light sources and LED devices.
研究领域:
材料科学
·
光学工程
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高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2026
·
IF 3.1
An Zhuoqing,Liang Weiwen,Gao Yuan,Chen Jiajing
The viscosity of the CaO–MgO–Al 2 O 3 –SiO 2 system containing La 2 O 3 and Fe 2 O 3 was measured by rotation, hot-stage microscopy and hot-stage load methods to investigate the rheological behavior across multiple temperature ranges. In-situ high temperature Raman spectroscopy was employed to quantitatively analyze the microstructure. The results show that with the La 2 O 3 /Fe 2 O 3 ratio varying from 2/0 to 0/2, the viscosity decreases gradually through the multiple temperature ranges, and the viscous flow activation energy also gradually decreases. As the ratio of La 2 O 3 /Fe 2 O 3 decreases, the relative contents of Q 0 , Q 1 and Q 2 increase gradually, and the relative contents of Q 3 and Q 4 decrease significantly. This indicates that both La 2 O 3 and Fe 2 O 3 act as network modifiers and simplify the glass network structure, resulting in a decrease in the degree of network polymerization and viscosity over the multiple temperature range. Compared to La 2 O 3 , Fe 2 O 3 is a more effective network modifier, as it breaks up the silicate network more efficiently and results in a lower overall viscosity. In addition, the microstructure of the melts was quantitatively analyzed by NBO/ T , and a quantified relationship among viscosity, microstructure and temperature was given.
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高影响因子
BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Zheng-Zhe Zhang,Ya-Fei Cheng,Lian-Zeng-Ji Xu,Yu-Hui Bai,Jia-Jia Xu,Zhi-Jian Shi,Yang-Yang Shen,Ren-Cun Jin
The increasing use of engineered metal oxide nanoparticles (MONPs) in consumer products raises great concerns about their environmental impacts, but their potential impacts on anaerobic ammonium oxidation (anammox) process in wastewater treatment remain unclear. In this study, the presence of MONPs (1, 50, 200 mg L −1 ) exhibited no visible effects on the nitrogen removal performance of anammox reactors, but high levels (200 mg L −1 ) of SiO 2 NPs, Al 2 O 3 NPs and CeO 2 NPs had a distinct effect on shaping the anammox community. Long-term exposure of MONPs caused different responses in the relative abundance of Ca. Kuenenia , the level of functional gene Hzs A and the activities of three key enzymes involved in anammox metabolism, but no significant inhibition effects on specific anammox activity were detected. Overall, the effects of MONPs on anammox community structure and sludge properties depended on their types and levels and followed the order SiO 2 > CeO 2 > Al 2 O 3 > TiO 2 .
研究领域:
环境科学
·
废水处理
·
微生物学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）