MATERIALS CHEMISTRY AND PHYSICS
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2025
·
IF 4.7
Qiuping Li,Zerong Duan,Guanghua Wen,Ping Tang,Zibing Hou
Low-basicity fluorine-containing mold flux, which forms a porous slag film with NaF pores, is expected to solve the contradiction between heat transfer and lubrication in the continuous casting process of peritectic steel. Herein, slag films were obtained by slag film heat flow simulator, and the thermal control of NaF pores in the slag film was evaluated by COMSOL. Based on the influence of fluorides on NaF gas generation, mold fluxes consisting of NaF, CaF 2 , and Na 3 AlF 6 were investigated separately at a basicity of 0.9 and a fluorine content of 6 wt%. The comprehensive heat control ability of these slag films ranked in the order: Na 3 AlF 6 > CaF 2 > NaF. Firstly, the slag film using NaF raw material exhibited larger NaF pores (30–50 μm), resulting in higher radiative transmittance and reduced thermal resistance. Its heat control is primarily dominated by the thickness of the film. Further, using CaF 2 raw material, the heat control ability and pore size were between NaF and Na 3 AlF 6 . Its slag film exhibited the highest surface roughness (27.32 μm), with interfacial thermal resistance playing a dominant role. With Na 3 AlF 6 as the fluorine source, the slag film exhibited finer and more uniformly distributed pores (10–30 μm), which enhanced reflectivity and reduced radiative heat transfer. Therefore, this study highlights that Na 3 AlF 6 as a raw material is conducive to low-basicity mold fluxes achieving thermal control through finely dispersed NaF pores.
研究领域:
材料科学
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冶金工程
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DOI
高影响因子
Scientific Reports
·
2016
·Vol. 6
·期 1
·1-9
·
IF 5.228
Kong Lingjun,Liu Mingxiang,Diao Zenghui,Chen Diyun,Chang Xiangyang,Xiong Ya
Hierarchical nanoporous carbon (NPC) with great surface area and developed pore size distribution has been intently concerned. Herein, we report a facile method coupling template nanocasting and self-activation to fabricate nanoporous carbon with continuous micro, meso and macro pores, in which CaCO 3 acted as template and activation reagent while the flour was the carbon precursor. Effects of mass ratio of CaCO 3 to flour and carbonized temperature on the pore structures of NPC were investigated by nitrogen adsorption-desorption isotherms and SEM analysis. Another kind of carbon was prepared by directly mixed powder CaCO 3 with flour carbonized at 800 °C (NPC-p) to comparatively investigate the pore fabricating mechanism. Results shown that carbonized at 800 °C was favorable to fabricate the continuous macro, meso and micro pores. The resulted NPC in a mass ratio of 1 to 2 had the considerable S BET and V T of 575.4 m 2 /g and 0.704 cm 3 /g, respectively. Only surface activation was observed for NPC-p. Nanocasting of the powder CaCO 3 contributed to fabricate macropores and the CO 2 activation contributed to meso- and micropores. Coupling activation and nanocasting effect due to the decomposition of CaCO 3 template into CO 2 and CaO was ascribed to synthesize the nanoporous carbon.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yang Wu,Kai Xu,Ruiming Yin,Jing Li,Ruimeng Xue
In the traditional raw materials used for preparing Sialon ceramics, hydrolytic AlN , cannot easily be used for aqueous gelcasting. To overcome this problem, a new type of gelcasting technique was developed. By introducing 1-methyl-2-pyrrolidinone (NMP) as a solvent, Sialon ceramics were formed using a low-viscosity non-aqueous gel system based on the 2-hydroxyethyl methacrylate (HEMA) gelling agent in this work. Based on this gel system, the rheological properties of the slurry and the solidification and sintering properties of Sialon ceramics were studied. The results show that the best rheological properties of slurry can be obtained with the dispersant dosage of 6 vol%. As the HEMA content increases, the flexural strength of the green bodies increase. When the ratio of HEMA to TMPTA (trimethylolpropane triacrylate) is 10:1 and the HEMA content is 15 wt%, the flexural strength of the green body reaches a maximum of 13.07 MPa. β′-Sialon ceramic has the best comprehensive mechanical properties at the sintering temperature of 1700 °C. Its bulk density, Vickers hardness , fracture toughness and flexural strength were 3.207 g/cm 3 , 1484 HV, 7.11 MPa m 1/2 and 351 MPa, respectively.
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
JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Xiaolong Gong,Wenming Jiang,Shengli Hu,Zhiyuan Yang,Xinwang Liu,Zitian Fan
Clay sand casting generates a large amount of foundry dust (FD), and the presence of coal powder in the FD makes it difficult to recycle and utilize. The landfill of the FD creates a serious environmental pollution and wastes a valuable resource. To improve the above situation, the FD was analyzed and characterized by X-ray fluorescence spectrometer (XRF), X-ray diffraction (XRD) and electron probe microanalyzer (EPMA). An ultrasonic-assisted flotation process was developed for the comprehensive utilization of the FD, and the effects of ultrasonic time on the flotation performance and flotation kinetics were investigated. In addition, the two-stage flotation of the FD was conducted. Obtained results showed that the FD mainly consisted of coal powder and clay minerals, and the coal powder was covered by clay minerals. The separation efficiency of the coal powder and clay minerals can be significantly enhanced by ultrasonic pretreatment , and the optimal ultrasonic time was 30 min. The flotation kinetics analysis results indicated that the first-order model with rectangular distribution was more reasonable for the data fitting of the ultrasonic-assisted flotation. Furthermore, the concentrate and tailings obtained by the two-stage flotation had achieved an acceptable result, favoring the comprehensive utilization of the FD.
研究领域:
环境科学
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材料科学
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矿物加工工程
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产品关联
DOI
PubMed
高影响因子
International Journal of Applied Ceramic Technology
·
2024
·
IF 1.8
Heng Zhang,Dongxu Yao,Yongfeng Xia,Yu-Ping Zeng
Porous Si 3 N 4 ceramics were prepared using the low-toxicity monomer HEMA (2-hydroxyethyl methacrylate) via a modified gel casting method. The rheological properties of Si 3 N 4 slurries were investigated. Triethanolamine with high activity was used as a catalyst and modifier for gelation reactions, effectively improving the curing rate and suppressing the inherent surface oxygen inhibition in such process systems. With an increase in solid loading of the slurry, the drying shrinkage (12.3% to 5.4%) significantly decreased, while the green body density (44.0%–49.0%) and flexural strength (9.65–16.46 MPa) increased, demonstrating an excellent mechanical strength. After sintering at 1700°C, the porous Si 3 N 4 ceramics prepared with 24–36 vol% solid loading slurry exhibited a flexural strength of 144.39–193.66 MPa and a porosity of 55.8% to 49.0%. The dielectric constant and loss tangent at 30 GHz ranged from 2.88 to 3.38 and 1.17–1.56 × 10 −3 , respectively. These ceramics show promising potential applications in high-performance structural ceramics and high-temperature wave-transparent materials.
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
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Fucheng Guan,Shi Feng,Jianbin Sun,Qiang Yang,Yihang Zhang,Zheng Li,Jing Tao,Xinbin Ji,Yonghe Wang,Da Bao,Jing Guo,Sen Zhang
Bio-aerogels have attracted much attention owing to their remarkable properties, but their brittle and poor elasticity has limited their further applications. Here, we propose a strategy of in-situ silanization crosslinking combined with unidirectional freeze casting (SUFC) to prepare superelastic sodium alginate (SA) aerogels. The resulting aerogel was ultra-light (0.048 g/cm 3 ), high porosity (96.86 %), and self-extinguishing from fire. Aerogels exhibited anisotropic properties, such as low-temperature elasticity (500 g compression at −70 °C 10-cycle, 99.6 % recovery), exceptional fatigue resistance (100-cycle at 50 % strain), and excellent thermal insulation (0.0696 W·m −1 ·K −1 ). Thus, the SUFC strategy provides considerable freedom for constructing multi-material, lamellar/honeycomb structured alginate-based aerogels, which pave the way to thermal insulation development at low temperatures.
研究领域:
材料科学
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生物材料
·
能源与环境
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产品关联
DOI
PubMed
高影响因子
Advances in Applied Ceramics
·
2017
·
IF 1.325
Yuanyuan Sun,Jingde Zhang,Shuaishuai Lu,Huichao Liu
Porous cordierite ceramics were synthesised by gel-casting method, using talcum powder, kaolin and alumina as raw materials. Organic monomers and cross-linker were used as additives. The phase composition and microstructure were investigated by X-ray diffraction and scanning electron microscope. The open porosity, compressive strength and thermal expansion coefficient were tested by the Archimedes method, universal testing machine and thermal expansion instrument, respectively. The results indicate that sintering temperature and holding time have a great influence on the cordierite properties. We obtain the good performance of porous cordierite ceramic sintering at 1350°C for 3 h. The cordierite phase content in the sample is higher and the crystallinity is better. At this point, the porosity is 58.53%, the compressive strength is 22.44 MPa and thermal expansion coefficient reaches 1.69 × 10−6 °C−1.
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
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Pengxin Zeng,Chuanwen Zhao,Xinmei Wang,Xinzheng Wei,Jian Sun,Ruiling Wang,Yafei Guo
The desirable CO 2 adsorption capacity and mechanical property are both important for the large-scale industrial applications of K 2 CO 3 -based CO 2 adsorbents. In this work, graphite-casted, Al 2 O 3 -supported, K 2 CO 3 -based pellets were prepared for CO 2 adsorption. The prepared K 2 CO 3 -based pellets containing 30 wt% of K 2 CO 3 calcinated at 900 °C exhibit CO 2 adsorption capacity of 1.4 mmol/g, which is over 2.5 times that of the pellets calcinated at 300 °C. It is mainly attributed to the residual graphite coating on the surface of the K 2 CO 3 -based pellets calcinated at 300 °C, which inhibits the diffusion of H 2 O due to the hydrophobicity of graphite and further causes the poor carbonation performance. Moreover, the addition of 40 wt% of microcrystalline cellulose can further enhance the adsorption capacity of the graphite-casted K 2 CO 3 -based pellets to ∼1.95 mmol/g due to the improved pore structure. However, excessive addition of microcrystalline cellulose (50–60 wt%) will lead to poor CO 2 adsorption performance (1.07–1.16 mmol/g) because of the active sites within the pellets being covered by molten K 2 CO 3 . Additionally, the structurally improved K 2 CO 3 -based pellets also exhibit desirable mechanical property with a compression strength of 69.45 MPa. Comprehensively considering the simple and easily scaled-up preparation route of graphite-casting method, the structurally improved, graphite-casted, Al 2 O 3 -supported, K 2 CO 3 -based pellets possess potential practical application prospect.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2021
·Vol. 24
·期 1
·2101088
·
IF 3.862
Zhuyin Chen,Chuanzong Wu,Xinli Liu,Ting Shen,Lei Zhang
Herein, porous titanium materials with honeycomb pore structure are prepared by freeze casting. The effect of freezing temperature on the pore structure and mechanical properties is also investigated. As the freezing temperature decreases from −10 to −50 °C, the compressive strength decreases from 79.5 ± 9.2 to 55.0 ± 4.3 MPa, and then increases to 90.1 ± 4.4 MPa. Porous titanium with an average pore size of 111.3 ± 25.2 μm and porosity over 60% are obtained at −10 °C. And the porous titanium is observed to form a neatly arranged nanopore structure with an average pore size of 28.5 ± 2.8 nm on the surface after anodizing. These nanopore structures can promote MG-63 cell adhesion and proliferation, thus improving the biocompatibility of porous titanium. Further, in the simulated body fluid culture experiment, culturing for 3 days can induce Ca 2+ and PO 4 3− to nucleate and deposit on the surface of anodized porous titanium, while 7 days can deposit a lot of apatite on the surface. In contrast, no apatite deposition is observed on the surface of the porous titanium sample without anodizing. These prepared porous titanium materials with high porosity, large pore size, sufficient mechanical properties, good biocompatibility, and biological activity might be a potential biomedical material.
研究领域:
材料科学
·
生物医学工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Shuang Yin,Limei Pan,Xia Fang,Yufeng Li,Yanpu Li,Yongbao Feng,Tai Qiu,Jian Yang
In this study, the low–toxicity monomer N, N–dimethylacrylamide (DMAA), serving as both gelling agent and pore–forming agent, was adopted to fabricate porous Si 3 N 4 ceramics with a regulatable microstructure and property by aqueous gelcasting. Results indicate that monomer content played an important role in regulating and optimizing the properties of sintered bodies. With increasing monomer content (5.94–30.69 wt%), both slurry viscosity (maximum 0.14 Pa s at 95.40 s −1 ) and green body strength (11.35–49.23 MPa) exhibited monotonic increasing trends, demonstrating superior mechanical properties to those obtained using the neurovirulent acrylamide (AM) gelling system. The increased monomer content not only improved porosity, but also promoted α→β–Si 3 N 4 transformation as well as β–Si 3 N 4 grain growth through enhancing the connectivity of interlocking pores and accelerating the vapor phase transport during liquid–phase sintering. These variations in phase composition and microstructure derived from the varied monomer content further resulted in monotonic changes in porosity (40.32–51.50%), mean pore size (0.27–0.38 μm), flexural strength (202.77–132.15 MPa), fracture toughness (2.93–2.32 MPa m 1/2 ), dielectric constant (3.48–2.78) and loss (3.52–3.09 × 10 −3 ) at 10 GHz for sintered bodies, displaying an excellent comprehensive properties. This study suggests a promising prospect for DMAA in preparation of high–performance porous Si 3 N 4 ceramics by aqueous gelcasting.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
Materials
·
2025
·Vol. 18
·期 9
·1988
·
IF 3.2
Yushi Qi,Fangming Wei,Yu Wang,Yu Jin,Xusheng Chang,Gang Chen
To enhance the mechanical properties of 6082 aluminum alloy, a novel Sc- and Zr-microalloyed 6082 alloy was fabricated through squeeze casting technology. Microalloying with Sc and Zr substantially refined the microstructure of alloy, achieving an average grain size of 136.36 μm—a 31.7% reduction compared to the baseline 6082 alloy. Furthermore, the addition of Sc and Zr effectively refined the coarse AlFeMnSi intermetallic phases, mitigating their inherent brittleness. The Sc/Zr-modified alloy exhibited delayed age-hardening kinetics, requiring 100% longer aging time to reach peak hardness due to Sc/Zr-induced retardation of β’’-phase precipitation. The optimized alloy demonstrated better mechanical properties, showing 10.4%, 8.0%, and 71.8% enhancements in yield strength, ultimate tensile strength, and elongation, respectively, over the non-microalloyed counterpart. The squeeze-cast Sc/Zr-modified alloy valve body showed yield strength exceeding 300 MPa and elongation above 10% across various sections, which verifies the effectiveness of this integrated microalloying and forming approach.
研究领域:
材料科学
·
金属加工工程
✓ 已验证
DOI
PubMed
高影响因子
MATERIALS LETTERS
·
2024
·
IF 2.7
Xiaohua Li,Kunfeng Li,Huilong Shao,Shuang Zhao,Guobing Chen,Zhen Zhang,Zhicong Gan,Yilong Song,Zichun Yang
The freeze-casting is widely utilized as a tool for regulating micro-scale pore structures in the fabrication of flexible polyimide (PI) aerogels for applications in adsorption, filtration, and fire-retardant. Herein, a confinement-controlled freeze-casting method is developed to fabricate PI aerogels with excellent thermal insulation properties by designing multi-scale structural adaptability. In a confinement-controlled system, the enhanced solid/solid and solid/liquid interface interactions in the solution dispersion system induce dendritic evolution of ice crystals. Under the directional freezing, grown dendritic ice crystals squeeze the loaded particles to form polyamic acid salt (PAAs) cryogels. Followed by template removal and thermal imidization, PI aerogels with a micro/nano-scale slit-like porous structure were obtained. The PI aerogels are characterized by ultra-low density (as low as 9.82 mg/cm 3 ) and exceptional thermal insulation performance (25.0 mW/(m·K) at 25 °C).
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
危险品化学品经营许可证（带存储）