JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2022
·
IF 6.364
Wenjie Li,Tianliang Pang,Hang Liu,Chen Wang,Mingwei Li,Xiaodong He,Fei He
Mullite fibers/whiskers hierarchical structure materials (MFWs) were prepared via the three-stage method, i.e. seeds breeding, precursors introducing and whiskers growth. The mechanism of low-temperature in-situ synthesis of mullite whiskers during gas-phase reaction process has been discussed in detail. The seeds bred on mullite fibers (MFs) are the growth points and can effectively reduce the subsequent growth temperature of mullite whiskers (MWs). The precursors composed of aluminum source, silicon source and catalyst provided raw materials for whiskers growth. Under the heat treatment temperature of 800 °C, mullite seed grains were guided to in-situ transform into MWs. Moreover, MFWs fabricated via low-temperature in-situ growth mechanism on the MFs present low density (0.103–0.147 g/cm 3 ) and ultralow thermal conductivity (0.0426–0.0514 W·m −1 ·K −1 ). Due to the lower whiskers growth temperature in this work than the ones in the most recent literatures, the three-stage method can be regarded as a viable strategy for low-temperature in-situ growth whiskers.
研究领域:
材料科学
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热工技术
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2014
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IF 0.987
Shuhua Zhong,Huaili Sha,Yu He,Gongwu Song
In this work, tobermorite/SiO2/Fe3O4 composites were designed and synthesized by hydrothermal method for the treatment of phosphorus in wastewater. The composites were characterized by scanning electron microscopy and X-ray diffraction. The removal efficiency of phosphorus on the tobermorite/SiO2/Fe3O4 composites was carried out and investigated under various conditions, such as contact time, sorbent content, and pH. After the multi-run experiments, the phosphorous elimination of the tobermorite/SiO2/Fe3O4 composites was declined slightly comparing with the first-run experiments. Compared with the conventional crystallization methods, tobermorite/SiO2/Fe3O4 composites not only gave high efficiency to remove phosphorus from wastewater without any complicated pretreatment, but also provided excellent magnetic properties for separating the phosphorus from water, which made it easy recycled. Moreover, tobermorite/SiO2/Fe3O4 composites had excellent P-elimination properties even in the strong acidic or basic conditions. Therefore, tobermorite/SiO2/Fe3O4 composites were important candidate for water quality control and protection.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2023
·Vol. 20
·期 3
·1740-1752
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IF 2.1
Ling Pan,Pengju Chen,Peng Xiao,Ling He,Wei Zhou,Yang Li
The mullite and ytterbium disilicate (β-Yb 2 Si 2 O 7 ) powders as starting materials for the Yb 2 Si 2 O 7 /mullite/SiC tri-layer coating are synthesized by a sol–gel method. The effect of SiC whiskers on the anti-oxidation properties of Yb 2 Si 2 O 7 /mullite/SiC tri-layer coating for C/SiC composites in the air environment is deeply studied. Results show that the formation temperature and complete transition temperature of mullite were 800–1000 and 1300°C, respectively. Yb 2 SiO 5 , α-Yb 2 Si 2 O 7 , and β-Yb 2 Si 2 O 7 were gradually formed between 800 and 1000°C, and Yb 2 SiO 5 and α-Yb 2 Si 2 O 7 were completely transformed into β-Yb 2 Si 2 O 7 at a temperature above 1200°C. The weight loss of Yb 2 Si 2 O 7 /(SiC w –mullite)/SiC tri-layer coating coated specimens was 0.15 × 10 −3 g cm −2 after 200 h oxidation at 1400°C, which is lower than that of Yb 2 Si 2 O 7 /mullite/SiC tri-layer coating (2.84 × 10 −3 g cm −2 ). The SiC whiskers in mullite middle coating can not only alleviate the coefficient of thermal expansion difference between mullite middle coating and β-Yb 2 Si 2 O 7 outer coating, but also improve the self-healing performance of the mullite middle coating owing to the self-healing aluminosilicate glass phase formed by the reaction between SiO 2 (oxidation of SiC whiskers) and mullite particles.
研究领域:
材料科学
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陶瓷学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Sustainable Metallurgy
·
2022
·Vol. 8
·期 3
·1117-1129
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IF 3.068
Lu Xingwen,Zhou Ceng,Liu Yuxin,Wang Yujie,Wang Fei
In this study, iron tailings were used as raw materials mixing with Al 2 O 3 , SiO 2 , and/or CaO sintered at 950–1400 °C to produce glass ceramics. In Al 2 O 3 /tailing and Al 2 O 3 /SiO 2 /tailing systems, the newly formed crystalline mullite (3Al 2 O 3 ·2SiO 2 ) reached its maximum content of 83.7 wt% for sample with Al 2 O 3 /SiO 2 /tailing mass ratio of 6/2/2. In Al 2 O 3 /SiO 2 /CaO/tailing system, the content of newly formed anorthite (CaAl 2 Si 2 O 8 ) increased to the maximum of 72.9 wt% for sample with Al 2 O 3 /SiO 2 /CaO/tailing mass ratio of 7/8/4/6 sintered at 1450 °C. The properties of glass ceramic products were significantly improved in samples with high content of crystalline mullite or anorthite and low surface porosity. Obtained glass ceramic in Al 2 O 3 /SiO 2 /tailing system with mass ratio of 6/2/6 showed excellent properties of chemical resistance (99.99%), compressive strength (1061.6 MPa), and low water absorption (0.2%). The high performance of glass ceramics and low leachability of hazardous metals shed light on the potential application of iron tailings in building and decorative materials. Graphical Abstract
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Hanqi Xu,Dexiang Li,Ruiwen Luo,Yujun Zhao,Hongjiu Su
The exceptional characteristics of mullite render it a significant candidate for application across several domains. However, finding ways to lower the synthesis temperature of mullite without compromising its purity has been an acknowledged challenge. In this work, we synthesized colloidal mullite precursors featuring a composite structure via ion exchange method and hydrolytic precipitation reaction of hydroxyl-aluminum chloride and effectively prepared high-content mullite materials at low temperatures. The crystalline phase transformations of the composite precursors with varying abundances of aluminum and silicon atoms during the calcination process were examined using X-ray diffraction and thermal analyzer techniques. The silicon-rich precursor was observed to form the mullite phase at 550 °C, with a mullitization rate of approximately 20.08 wt%. In addition, the molecular characterization of the calcined samples, utilizing nuclear magnetic resonance to analyze the near-neighborhood environment and X-ray photoelectron spectroscopy to elucidate surface structure, revealed that no substantial structural rearrangement occurs in the Si-rich samples as the calcination temperature increases. More aluminum and silicon atoms form a homogeneous structure and contribute to the mullite crystallization process. Based on the provided characterization analyses, it is plausible to deduce that the low-temperature crystallization of mullite is associated with the significant mixing of Al and Si species in the precursor at the atomic level. More specifically, the abundance of amorphous silica particles in the Si-rich samples facilitates the formation of massive mullite-like Si-O-Al bonds with aluminum, owing to its migratory and viscous deformation characteristics. Therefore, during the calcination process, the grains begin to grow exponentially through the grain boundary migration mechanism once the crystallization of the mullite phase is complete.
研究领域:
材料科学
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无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Lingjiao Zhan,Chaozhong Wu,Fuqin Zhang,Juan Wang,Haotian Liu,Yutong Chen,Shuwei Yao,Yunzhu Ma,Wensheng Liu
The coordinated regulation for α-Al 2 O 3 and mullite structures in the alumina-mullite duplex fiber poses a challenging yet crucial task in achieving a fiber with exceptional high-temperature properties. In this study, Fe element was added into the alumina-mullite fibers in the form of iron sol and ferric nitrate solution, respectively, with the aim of obtaining a fiber consisting of fine mullite grains embedded with nano α-Al 2 O 3 grains. The results revealed that the addition of Fe element significantly enhances the crystallization process of mullite in alumina-mullite fibers. Specifically, adding iron sol resulted in the reduce of α-Al 2 O 3 formation temperature to 1300 °C, while introducing Ferric nitrate solution promoted the formation of mullite phase. Simultaneous introduction of 1.3 wt% iron sol and 1.3 wt% Ferric nitrate solution contributed to achieve alumina-mullite fiber with tensile strength of 2.06 GPa. In addition, the influence mechanism of Fe source on the phase transformation and microstructures of alumina-mullite fiber were discussed.
研究领域:
材料科学
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陶瓷学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jiamei Xu,Zijian Su,Jicheng Liu,Kun Lin,Yuanbo Zhang
With the improvement of industrial production requirements, the thermal shock resistance (TSR) of the materials used in industrial kilns plays a crucial role in ensuring efficient production. Aluminum-based heat storage ceramic balls (HSCB) are widely used in high-temperature industrial kilns, but they have a problem of weak TSR. A similar situation existed in the HSCB with corundum and Mg-Al spinel phases in our previous research. In this study, corundum-spinel-mullite HSCB was prepared using pre-treated secondary aluminum dross (SAD) as the main material at low roasting temperature. The effects of mullite content on the mechanical properties and microstructure of the HSCB were studied. Mullite whiskers were cross-distributed with corundum and Mg-Al spinel, which benefited the TSR. With the increase of mullite content, the structure of the HSCB gradually became loosely, the TSR increased and then decreased slightly, and linear crack density increased. When mullite content was about 25 %, the comprehensive performance of HSCB performed perfectly. Under the optimal conditions, the coefficient of thermal expansion of the HSCB was only 5.70 × 10 −6 K −1 , the thermal conductivity reached 3.35 W/(m·K) and the TSR was 34 times. This study aimed to provide a theoretical reference for the preparation of aluminum-based ceramic HSCB, as well as to improve the high-value utilization of SAD.
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
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yukun Cao,Zhenfei Lv,Ke Zhang,Chong Lan,Mengke Fan,Xu Lu,Yanghui Ke,Wenbo Guo,Yixian Yang,Xin Wang,Xiulin Shen
Using waste electric porcelain to produce refractory bricks is a viable technology. However, these bricks currently have lower mechanical strength compared to those made from mineral raw materials. This study optimized the proportions and sintering process to develop high-strength refractory bricks from waste electric porcelain. The impact of physical phase, crystallinity, sintering temperature, and fly ash content on the bricks properties was examined. The research found that low crystallinity in waste electric porcelain leads to disorganized growth of mullite nano whiskers at high temperatures, reducing mechanical strength due to insufficient support structures and stress concentration zones. The addition of fly ash promotes the formation of uniformly dispersed mullite columns through non-uniform nucleation, significantly improving mechanical properties by creating a collective tetrahedral structure. Bricks with 20 wt% fly ash sintered at 1440 °C achieved a flexural strength of 77.3 MPa, a compressive strength of 156 MPa, and an apparent porosity of 10.89 %. High-temperature simulations indicate that these bricks exhibit good compressive strength and deformation resistance, with no adhesion observed. These high strength refractory bricks have promising potential for use in various high-temperature applications, including kiln linings, high-temperature flue, high-temperature support components and other industrial processes where durability and thermal stability are critical.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Zhongliu Wen,Xiaolei Song,Dongchu Chen,Ting Fan,Yang Liu,Qingshan Cai
In this work, diphasic mullite (3Al 2 O 3 ·2SiO 2 ) nanofibers with good homogeneity were prepared by electrospinning method. Aluminum nitrate (AN) and aluminum isopropoxide (AIP) were used as alumina sources, commercial colloidal silica as silica source, and polyvinyl alcohol (PVA) as polymer additive . Precursor nanofibers with continuous and uniform structures were acquired at mass ratio of PVA to precursor sol from 0.06 to 0.09. γ- Al 2 O 3 phase was obtained at 878 ° C and mullite phase formed at 1322 ° C upon heating of the precursor under air atmosphere. Calcined samples suggested mullite as dominant phase at 1300 ° C and amorphous SiO 2 could even exist at 1400 ° C. As-prepared nanofibers possessed continuous structures with subequal average diameters at 900–1200 °C. However, such morphological characteristics were lost at temperatures above 1300 ° C due to rapid growth of crystal grains. Al and Si elements were uniformly distributed in fibers and mixed at nanoscale, confirming homogeneity and diphasic features of nanofibers.
研究领域:
材料科学
·
陶瓷学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xuan Hou,Shuhua Ma,Xiaohui Wang,Ruiping Liu,Muhammad Ibrahim
In the study of hydrothermal conversion of fly ash to calcium silicate hydrates (C–S–H), the concentration of Ca and Si in the liquid phase plays a vital role in determining the hydrothermal transformation results. This paper selected a fly ash as a research object, which can leach a high Si concentration into the solution in the hydrothermal process even in a slight alkaline solution, based on a new finding when studying the alkali dissolution kinetics of different fly ashes. To explore the effects of Ca and Si concentrations in the liquid phase on the hydrothermal transformation of fly ash to tobermorite or katoite, Na 2 SiO 3 (Na 2 O·xSiO 2 ·yH 2 O) and CaSO 4 were used to change the concentration of Si and Ca in the liquid in the hydrothermal system. Characterization methods such as XRD, SEM, infrared spectroscopy, and solid-state nuclear magnetic resonance indicated that a little more concentration of Si can promote the transformation from fly ash to tobermorite and persuade the conversion of the Si–O tetrahedron in C–S–H from Q 2 to Q 3 and Q 4 . However, too high a liquid Si concentration made the hydrothermal product change to colloidal calcium silicate. On the other hand, a high Ca concentration in the liquid was found to lead to the conversion of the hydrothermal product from tobermorite to katoite. According to the above results, the deep transformation from fly ash to tobermorite under the conditions of a low temperature of 160 °C and no extra alkali addition was achieved by the induction of a small quantity of Na 2 SiO 3 .
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Asian Ceramic Societies
·
2020
·
IF 2.653
Mengmeng Yang,Jijia Li,Yiran Man,Zijun Peng,Xiaofang Zhang,Xudong Luo
A three-dimensional mullite-whiskers network ceramic with ultra-light weight and high-strength was obtained by the foaming gel-casting method with active mulllite powders and NH4F. Ultrafine active mullite powder was used as the raw material and SDS (sodium dodecyl sulfate) as a pore-forming agent. The effects of sintering temperature on the microstructure, flexural strength and thermal conductivity of the porous ceramics were systematically investigated. The mullite-whisker network porous ceramic has a fibrous-framework structure composed of interweaving mullite-whiskers. Because the pore-walls are composed of interlacing whiskers and the pores are filled with whiskers, the porous ceramics exhibited good mechanical properties and low thermal conductivity. The flexural strength of the obtained mullite-whisker porous ceramic sintered at 1500°C was up to 1.45 Mpa, while the porosity was as high as 89%. In addition, the thermal conductivity of the porous ceramic at room temperature was as low as 0.045 W/m⋅K.
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Lang Zhang,Haibo Wu,Zehua Liu,Yitian Yang,Huan Liu,Xishi Wu,Bingbing Pei,Jianshen Han,Zhengren Huang
The mullite-whisker-modified SiC porous ceramics were prepared by the oxide bonding method, using two additives (MoO 3 as a mineralizer and AlF 3 as a crystallization catalyst) to promote the growth of mullite whiskers. The microstructure and comprehensive properties of the sintered bodies were adjusted by controlling the sintering temperature and the additive content. The mullite whiskers obtained by controlling the sintering temperature and additives exhibit excellent microstructural characteristics (diameter: 0.1–0.5 μm, length: 3–6 μm, length-to-diameter ratio: 15–25). These formed mullite whiskers effectively intercepted particulate matter, and their interlocking structure provided higher strength to the sintered body. The resultant mullite-whisker-modified SiC porous ceramics demonstrated remarkable mechanical strength (43.8 ± 0.1 MPa) while maintaining high porosity (41.27 %) and excellent gas permeability (1.96 × 10 −14 m 2 ). After undergoing five thermal shock cycles at 850 °C, the material retained 92.69 % of its original strength and exhibited superior filtration efficiency of 99.6 % for PM2.5 particles.
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
危险品化学品经营许可证（带存储）