CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yanyan Deng,Luke Ma,Xueliang Pei,Qing Huang,Zhengren Huang
Additive manufacturing technology is being developed for manufacturing SiC ceramic parts with designed shape and microstructure. In this study, direct ink writing (DIW) was adopted to print SiC ceramic parts. To avoid incorporating volatile organic solvents or water, a SiC ceramic precursor liquid polycarbosilane (LPCS) was used as the binder of SiC powder and the rheological adjustment additive. The content of LPCS with the content and diameter of SiC powder were optimized to improve the fluidity of slurry, increase its ceramic yield and reduce its shrinkage during pyrolysis. According to the results of rheological analysis and shrinkage during pyrolysis, 78 wt% SiC powders composed of 40 nm SiC powder and 5 μm SiC powder in a ratio of 1:6 was appropriate. For achieving rapid solidification rate of the slurry at low temperature, a free‐radical initiator which can trigger the crosslinking of allyl group on LPCS was incorporated. According to the results of rheology, DSC and FT-IR, the preferred platform temperature for fast curing of DIW slurry was 150 °C. As the slurry accumulated layer by layer on heating platform, the cured green bodies were successfully prepared. After pyrolysis to 1200 °C, SiC ceramic parts were obtained with only 4.43 % linear shrinkage associated with the precursor-to-ceramic conversion. Because the shrinkage was limited, no obvious deformation or crack was found.
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高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 22
·13498-13509
·
IF 10.7
Ying Zhang,Chengqing Tang,Yaoqieyu Song,Sheng Zhang,Zhi Hong Hang,Xiaohua Zhang,Yitan Li,Zhaohui Yang
It is a critical challenge to construct a robust and efficient electromagnetic shielding system with tunable shielding behavior and interfacial properties to adapt to complicated extreme conditions. Here, we fabricate a ternary SiC@high-entropy alloy (HEA)@carbon nanotube sponge (CNTS) composite with designed heterogeneous interfaces and composition on a wide range of scales. On the atomic scale, the electromagnetic character of the composite can be easily regulated through adjusting the elemental composition of HEAs due to their high entropy effect and the cocktail effect. A nano-meter thick silicon carbide (SiC) layer on the HEA further generates a Schottky junction between the metal–SiC and CNTS–SiC to achieve an outstanding average electromagnetic interference (EMI) shielding performance of ca. 90 dB in the X-band on the nano scale (the maximum EMI SE of the 4 mm-thick sample is greater than 100 dB), accompanied with good elasticity and excellent chemical and thermal resistance to endure acid corrosion and high-temperature annealing on the micro scale. This work paves a pathway for designing and developing potential shielding composites with excellent and tunable EMI shielding performance and comprehensive characteristics for complicated application scenarios.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Wenyan Huang,Jiahao Hu,Yeqi Zhu,Jiahua Zhan,Rongdan Lei,Yuchen Sun,Kaiqi Chen,Siqi Lan,Rongqian Yao
As contemporary aerospace and radar-detecting technologies evolve, load bearing-microwave absorption integration of thermal protection materials for complex environment requirements are urgent. Well known for low density, good high-temperature resistance and superior tunable dielectric properties, polymer-derived ceramics (PDCs) promisingly meet most needs of high-performance aircraft thermal protection system (TPS). Aimed at promoting practical application, we integrate in-situ formed Ni 2 Si into lightweight SiC(rGO) nanocomposite PDCs via re-pyrolyzing coassembled nano-Ni/SiC(rGO) p /polycarbosilane-vinyltriethoxysilane-graphene oxide (PVG) blends to enhance their mechanical and electromagnetic wave (EMW) absorbing performances. Size effect on phase transition of Ni into Ni 2 Si (as brazing bonding agents) accompanied by volumetric expansion, ingeniously eliminates stretching stress from PVG precursor inward shrinkage for compact framework during re-pyrolysis. In-situ generated Ni/Ni 2 Si/C core-shell nanostructure (similar to nodular cast iron) has good chemical compatibility with β-SiC/SiO x C y /C free (rGO), thereby enables composites improved compactness and toughness. More interestingly, heterogeneous interfaces/defects among Ni, Ni 2 Si, carbon shell, β-SiC and SiO x C y /C free (rGO) matrix, effectively facilitate interfacial/dipole polarization for robust EMW absorption, and lightweight SiC(rGO, Ni 2 Si) Ni=4% nanocomposite PDCs exhibit outstanding fracture toughness of 6.56 MPa·m 1/2 and high compressive strength of 119.25 MPa. Such composite with structure-function integration maintain stable under butane blowtorch at ∼1300 °C, shedding light on a new route to mass-manufacture aerospace vehicle components.
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高影响因子
Journal of Manufacturing Processes
·
2024
·
IF 6.1
Shihao Sun,Qian Xia,Zikang Li,Shuhan Wang,Ziru Pei,Yichen Xu,Hongqiang Ru
Novel light and strong hierarchical porous mullite-bonded SiC structures with total porosity ranging from 68 % to 95 % were fabricated by combining material extrusion (MEX) and in-situ reaction bonding technique. These structures comprise three porosity families and wide porosity hierarchization over four orders of magnitude in length scales. The pore parameters were precisely controlled by the nozzle path and starch (as a poreforming agent) content. The sintering temperature effect on phase composition, porosity, sintering shrinkage, and mechanical properties was systematically investigated. As the SiC powders were sintered at 1550 °C, they were compactly bonded by mullite and cristobalite necks. The single filaments demonstrated a flexural strength of 74 MPa at a porosity of 35 %. The hierarchical porous mullite-bonded SiC lattice structure with a total porosity of 69 % was near-net-shape sintered and exhibited a compressive strength as high as 41 MPa. Such structures are highly promising for wide applications such as electromagnetic shielding, burners, membrane supports, porous burners, filters, thermal insulation , catalyst supports, etc.
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高影响因子
ChemSusChem
·
2024
·
IF 7.5
Shuo Wang,Mengting Liu,Yarao Gao,Hongyao Zhao,Hongyang Zhu,Rongrong Du,Yuyang Zheng,Zengjing Guo,Yanyun Wang,Yiyan Song,Fu Yang
Graphical In this study, a bimetallic hollow nanoreactor (Co@SiO 2 /Cu−X) was designed for the efficient degradation of antibiotics in medical wastewater. This nanoreactor is composed of ultrafine Cu and Co metal species in a mesoporous N-doped C-Silica heteroshell, and the synergistic interaction between the different metal species and the structural properties of the nanoreactor make the catalyst afford remarkable catalytic activity and excellent recovery stability during norfloxacin mineralization. Moreover, the photothermal properties of the nanoreactor enable it to exhibit excellent performance in solar-driven water evaporation, providing a dual strategy for wastewater remediation and clean water regeneration. In the face of complex water pollution challenges, this innovative design provides a promising solution for advanced water purification technologies. Growing attention has been paid to the rational treatment of antibiotics-bearing medical wastewater. However, the complexity of polluted wastewater makes the later comprehensive treatment difficult only by the Advanced Oxidation Process technique. Therefore, the coupled water treatment techniques including contaminant mineralization and regeneration of cleanwater become very attractive. A bimetallic functional hollow nanoreactor defined as (Co@SiO 2 /Cu−X) was successfully constructed by coating a Cu-doped silica layer on the metal-organic framework (ZIF-67) followed by programmed calcination in nitrogen. The nanoreactor was endowed with a hollow configuration composed of mesoporous N-doping C-Silica hybrid shell encapsulated ultrafine Cu and Co metallic species. Such a configuration allows for the efficient diffusion and open reaction space of big contaminant molecules. The catalytic synergy of exposed Co−Cu bimetals and the easy accessibility of electron-rich contaminants by polar N doping sites triggered surface affinity make the optimal Co@SiO 2 /Cu-6 afford an excellent catalytic norfloxacin mineralization activity (7 min, k abs =0.744 min −1 ) compared to Cu-free Co@SiO 2 -6 (k abs =0.493 min −1 ) and Co-6 (k abs =0.378 min −1 ) Benefiting from the above unique advantages, Co@SiO 2 /Cu-6 show excellent removal performance in degrading different pollutants (carbamazepine, oxytetracycline, tetracycline, and bisphenol A) and persistent recycled stability in removing NFX. In addition, by virtue of the excellent photothermal properties, interfacial solar water evaporation application by Co@SiO 2 /Cu-6 was further explored to reach the regeneration of cleanwater (1.595 kg m −2 h −1 , 97.51 %). The integration of pollutant mineralization and solar water evaporation by creating the monolith evaporation by anchoring the Co@SiO 2 /Cu-6 onto the tailored melamine sponge allows the regeneration of cleanwater (1.6 kg⋅m −2 ⋅h −1 ) and synchronous pollutant removal (NFX, 95 %, 60 min), which provides potential possibility the treatment of complicated wastewater.
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PubMed
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2024
·
IF 8.1
Wenjie Zhu,Yujie Wang,Yuwei Ren,Minghang Li,Yichun Bi,Ce Zheng,Xiaoqiang Li
High-purity Ti 3 SiC 2 MAX phase was introduced into the Amosic 3-303 SiC fiber-reinforced SiC matrix composite as a modified matrix by Reaction Melt Infiltration (RMI) at 1250 °C, realizing the generation of high-purity Ti 3 SiC 2 phase without residual melt and by-products in the RMI matrix. This modification reduced the porosity of the SiC f /SiC-Ti 3 SiC 2 composite from 10 to 20% typically found in SiC f /SiC composite prepared by Chemical Vapor Infiltration (CVI) to 6%, and the densification process cycle time by 70%. The flexural strength and thermal conductivity were enhanced by 12% and 58%, respectively. The microstructure and phase evolution of Ti 3 SiC 2 in the SiC f /SiC composite matrix was systematically investigated, offering new insights into the ceramic matrix growth process during RMI. This work proposes a new method for utilizing the RMI process to prepare high-performance nuclear SiC f /SiC-based composites.
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高影响因子
JOURNAL OF FLUORINE CHEMISTRY
·
2024
·
IF 1.7
Xiaoli Wei,Yiwei Sun,Jianhai Jiang,Zhen Wang,Wei Zhang,Bing Liu,Shucheng Wang,Xiaodan Yang,Wanjin Yu,Jianjun Zhang,Wenfeng Han
Al 2 O 3 exhibits high activity for the resource utilization of potent greenhouse gases, hydrofluorocarbons via dehydrofluorination or F/Cl exchange. However, it experiences completely fluorination under corrosive HF environment, leading to thorough fluorination of F-Al-O active site into F-Al-F, accompanied with serious carbon deposition. In this work, we successfully confined Al 2 O 3 in SiC (Al 2 O 3 @SiC) via treating Al 2 O 3 /SiC under high temperatures (>800 °C). The results showed that different with simple loaded Al 2 O 3 (Al 2 O 3 /SiC), during high temperature treatment, reaction between Al 2 O 3 and SiC occurred, leading to the confinement effect. Then, contributed by the interaction, desired F-Al-O species could be stabilized on the surface of SiC. While for Al 2 O 3 /SiC, it thoroughly turned into AlF 3 under identical reactive conditions, leading to inferior stability during CH 3 CHF 2 dehydrofluorination. Furthermore, the reaction rate of 5 %Al 2 O 3 @SiC is nearly up to 4 folds higher than that of traditional AlF 3 . Facilitated by the suitable Lewis acid intensity, less carbon deposition formed on Al 2 O 3 @SiC. Thus, constructing strong interaction between F-Al-O and stable SiC provides a potential strategy to stabilize unstable active centers.
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高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Huan Yang,Cheng Fang,Hongliang Xu,Xia Zhang,Yang Liu,Jiayin Zhao,Anzhe Wang,Hongxia Lu,Hailong Wang
Controlled shrinkage of hydrothermal carbon coating (HTCC) during its carbonization preparation process offers a novel strategy for optimizing the interfacial properties of fiber-reinforced ceramic matrix materials. In this study, the effect of volumetric shrinkage in monolayer or bilayer HTCC on the interface characteristics and mechanical properties of C f /ZrB 2 -SiC composites is investigated. The bilayer HTCC significantly enhances the crack deflection effect within the interphase compared to the monolayer HTCC. By precisely controlling the shrinkage of the layers of the bilayer HTCC, an innovative C/SiC/C trilayer interphase was synthesized in situ during the polymer infiltration process for preparing the C f /ZrB 2 -SiC composites, which synergistically enhances stress dispersion and load transfer efficiency within the interface. The work of fracture for C f /ZrB 2 -SiC composites modified by the trilayer interphase has been significantly elevated to 2258 J/m 2 , which far exceeds the 129 J/m 2 measured for the composites lacking a HTCC interphase.
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高影响因子
MATERIALS & DESIGN
·
2025
·
IF 7.9
Meng Fu,Youchong Hu,Shuai Luo,Yuanyuan Li,Yaoqi Huang,Xiaomin Cheng
Developing multifunctional composite phase change materials (PCMs) featuring enhanced photothermal energy conversion and storage performance is of vital importance, yet traditional organic PCMs suffer from inherent drawbacks, including leakage and poor thermal conductivity throughout the phase change process. To solve this problem, a new PCM design is provided, where stearic acid (SA) was employed as a latent heat storage unit, and carbon foam (CF) was served as a supporting framework. In this design, CNTs/SiC composite nanoparticles were uniformly dispersed into epoxy resin (ER) to fabricate a photothermal conversion coating. The modified epoxy resin (MER) coating acted as a protective effect for the internal PCMs, effectively mitigating leakage during phase transitions. With the incorporation of 9 wt% CNTs/SiC, the prepared composite PCMs retained the high latent heat (143.5J⋅g −1 ) and excellent photothermal conversion efficiency (96.76 %). Furthermore, the latent heat of the material showed a minimal reduction of only 0.4 % following 200 thermal cycles. These results demonstrate the potential of composite PCMs for efficient solar energy harvesting and storage in thermal regulation systems.
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高影响因子
Energies
·
2025
·Vol. 18
·期 5
·1216
·
IF 3.2
Xiaojiao Wang,Libing Zhu,Yan You,Zhaoquan Zhang
Thermal conductivity is the key property of SiC-TRISO composite fuel. This study investigated the relationship between SiC phase transition, thermal conductivity, and microstructure across different temperatures. The physical phase, morphology, and microstructure of SiC and SiC-TRISO composite fuels were characterized by XRD and SEM. Meanwhile, EDS was employed to determine the chemical composition within SiC grains. The results showed the transformation of the β-SiC phase to α-SiC in the matrix with increasing sintering temperature, while Al, Y, and Ca concentrations within the SiC grains decreased. The highest λ value of SiC was achieved at a sintering temperature of 1750 °C, measuring 75.51Wm·Kat room temperature and 43.36Wm·Kat 500 °C. The incorporation of TRISO fuel lowered theλvalue of SiC-TRISO composite fuel, yielding 57.96 and 34.51Wm·Kat room temperature and 500 °C, respectively. The outermost carbon layer of TRISO fuel interacts with the silicon carbide matrix and liquid phase, facilitating the phase transition from 3C-SiC to 6H-SiC and, subsequently, to 4H-SiC. This process accelerates the depletion of Al, Y, and Ca within the silicon carbide grains, encourages grain growth, and raises the free-carbon content, thereby decreasing the λ of the composite fuel.
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高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Hengrui Zhang,Yunjia Xue,Liwen Yan,Anran Guo,Haiyan Du,Jiachen Liu
Aluminum silicate fiber fabric (ASFF) has been widely used in the outer surface of flexible insulation felt on the leeward side of aerospace vehicle. In order to improve the temperature resistance of ASFF, a kind of SiC–ZrC composite coating was prepared on the surface of fiber fabric via spraying method with SiC as emittance agent and ZrC as additive. The surface morphology and mechanical properties of the coating were studied. Compared with the single-component SiC coating, the composite coating could effectively avoid coating spalling and improve the surface integrity at high temperature. After thermal treatment at 1100 °C for 2 h, the interface bond strength of the composite coating/substrate was 52.41% higher than that of SiC coating/substrate. The tensile strength of fiber fabric with SiC–ZrC composite coating could reach 91.75 MPa, which was 101.76% higher than that of raw ASFF. Therefore, the SiC–ZrC coating could greatly improve the temperature resistance of ASFF, and has an attractive application prospect in the field of thermal protection system.
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高影响因子
Polymers
·
2022
·Vol. 14
·期 11
·2297
·
IF 4.967
Xupeng Song,Wei Yang,Shouchao Huo,Kun Wang,Yuanyuan Wu,Yun Chen,Jian Qiao,Boyang Shen,Xingming Bian
SiC/EP composites are promising insulating materials due to their high thermal conductivity, stable chemical properties, and nonlinear electrical conductivity. However, the compatibility of micron-sized SiC particles with the organic polymer matrix is poor, and defects such as air gaps may be introduced at the interface, which reduces the partial discharge resistance of the composite materials. In order to improve the partial discharge initial voltage (PDIV) of SiC/EP composites, in this paper, SiC/EP composites with different proportions were prepared by surface modification of filler and compound of micro/nano particles. Firstly, a method of secondary modification of SiC particles was proposed, which was first modified by alkali washing and then silane coupling agent KH560, and the effectiveness of the modification was verified. Therefore, the interface bonding ability between the filler and the matrix was improved, the air gap defects at the interface were reduced, and the PDIV of the composite material was improved. When the filling ratio is 10 wt%, the PDIV was enhanced by 13.75%, and when the filling ratio was further increased, the improvement was reduced. In contrast, the introduction of nanoparticles into the composites can effectively improve the PDIV of composite materials. In this study, nanoparticles were used to form a shell-core structure in epoxy resins to exert their huge specific surface area and active surface properties, thereby changing the overall crosslinking properties of the composites. Through experimental research, the optimal micro-nano particle compounding ratio was explored. Under the optimal mixing ratio, the PDIV of the composite material can be increased by more than 90%.
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高影响因子
危险品化学品经营许可证（带存储）