JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Dexuan Yan,Jiahui Chen,Yu Zhang,Yanzi Gou
In this work, a new approach to fabricate B 4 C/SiC ceramic hollow microsphere was established through combination of slurry-coating and precursor conversion method. Firstly, different slurries were prepared using modified B 4 C powder with addition of PCS and LPCS. Subsequently, slurry was coated on a POM microsphere, followed by crosslinking, POM decomposition and heat-treatment at 1100 °C. Finally, the B 4 C/SiC hollow microspheres with average diameter of 1.6–1.9 mm and thickness of 10–60 μm were obtained. The roughness (Ra) of outer surface was as low as 40.3 nm with high sphericity of 99.6%. Deoxidation was also explored by heat treatment at 1700 °C. The oxygen content was decreased from 11.06 wt.% to 0.37 wt.%, and crush load was promoted from 1.73 N to 4.50 N. The preparative method of B 4 C/SiC ceramic hollow microspheres in this work can be easily extended for large-scale production.
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高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Meng Zhang,Hui Lin,Shiqi Ding,Ting Wang,Zhenjiang Li,Alan Meng,Qingdang Li,Yusheng Lin
In this study, a practical lightweight and broadband microwave absorber, namely, the net-like amorphous carbon-coated silicon carbide coaxial nanocables (SiC@C NCs), which had low density and excellent physicochemical stability, was successfully fabricated according to the hydrothermal-carbonization strategy. Typically, the microwave absorption performance exhibited broad effective absorption bandwidth (EAB) of up to 7.2 GHz (9.12–16.32 GHz) at a small matching thickness of 2.58 mm. Meanwhile, the minimal reflection loss (RL) value of −51.53 dB with the corresponding EAB across the whole Ku-band (11.68–18 GHz) appeared at 2.08 mm, which suggested that, the as-prepared SiC@C NCs displayed extensive application prospects as a superior lightweight and broadband microwave absorber. Moreover, the systematic characterization results indicated that, the superior microwave absorption performance was ascribed to the interfacial polarization and multiple reflections on the heterogeneous interface between the SiC nanowires (SiC NWs) core and the amorphous carbon shell, together with the electron polarization and Debye dipolar relaxation resulted from the stacking faults of SiC NWs core, and the abundant defect and disorder within the amorphous carbon shell.
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高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Guangchao Xing,Chengji Deng,Jun Ding,Hongxi Zhu,Chao Yu
AlN-SiC porous composite ceramics were fabricated by heat-treating Al 4 SiC 4 porous ceramic green body prepared using the foaming method under flowing nitrogen. The porous structure could provide increased nitrogen diffusion channels, leading to a decrease in N 2 diffusion resistance and an increasing degree of nitridation. The micro-morphology of AlN was in the form of particles or whiskers and influenced by heating temperature and time parameters. AlN has good dispersibility with SiC particles, resulting in local homogeneous chemical composition of prepared AlN-SiC composite ceramics. Furthermore, the potential reaction mechanism responsible for the synthesis of AlN-SiC porous composite ceramics during the nitridation was revealed. This simple approach may be used for large-scale synthesis of AlN-SiC porous composite ceramics.
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高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Zhimin An,Rubing Zhang,Daining Fang
The monolithic silicon carbide (SiC) aerogels were converted from catechol-formaldehyde/silicon composite (CF/SiO 2 ) aerogels through carbothermal reduction and calcination . In the process of preparing the CF/SiO 2 aerogel, a new method was proposed to produce more silicon carbide and enhanced the mechanical properties of the SiC aerogel. This method was realized by adding an alkaline silica sol as supplemental silicon source. The principle process of CF/SiO 2 aerogels converting to SiC aerogels was discussed based on experiment and results analysis, while the microstructure, mechanical properties, and thermal properties of the prepared SiC aerogels were investigated. The results show that the as-synthesized SiC aerogels consist of β-SiC and a small amount of α-SiC nanocrystalline . It possessed a mesoporous structure and a low thermal conductivity 0.049 W/(m∙K), a relatively high compressive strength 1.32 MPa, and a relatively high specific surface area 162 m 2 /g. Due to their outstanding thermal and mechanical properties, the prepared SiC aerogels present potential applications in thermal insulation field, such as space shuttles and aerospace carrier thermal protection materials.
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高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Meng Liu,Yong Yang,Yuquan Wei,Yajie Li,Heng Zhang,Xuejian Liu,Zhengren Huang
High-purity SiC materials have been used in semiconductor processes due to their excellent properties. However, they are difficult to densify without sintering aids. In this work, dense and high-purity SiC ceramics have been obtained by pressureless solid-state-sintering with ultra-low contents of sintering additives. The amount of residual B, C and O in the high-purity SiC ceramics was less than 0.15 wt%, respectively, and the total content of other impurity elements (such as aluminum , magnesium, calcium, iron, etc.) was less than 0.015 wt%. Finally, the purity of the as-prepared SiC ceramics was more than 99.5 wt%.
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高影响因子
LANGMUIR
·
2018
·
IF 3.789
Youxing Liu,Jiaxiang Liu,Tianyu Yang
Highly dispersible SiC powder was prepared using sodium humate as a modifier. The results showed that the ζ-potential absolute value of the modified SiC powder increased from 13.1 to 38.7 mV when the adsorption capacity of sodium humate on the SiC surface was 2.368 mg/g. The slurry with a maximum solid content of 65 vol % was obtained using the modified SiC powder, and the minimum viscosity value was 0.322 Pa s at a solid content of 50 vol %. The adsorption kinetics equation of sodium humate on the SiC surface is t/qt = 0.6253t + 11.0472, which is in accordance with the pseudo-second-order kinetics model. In addition, the isotherm equation, ln qe = 0.461 ln Ce – 0.334, agrees with the Freundlich model. The adsorption energy of sodium humate on the SiC surface was 0.8280 kJ/mol, indicating that the adsorption type was physical adsorption.
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PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2018
·
IF 3.794
Jia-Qi Zheng,Jian Chen,Xue-Jian Liu,Zheng-Ren Huang,Jun-Jun Chen
Highly conductive SiC-MoSi 2 -AlN composites were fabricated by β-SiC, AlN and MoSi 2 powders with Y 2 O 3 additive via pressureless sintering. The effect of MoSi 2 content on the microstructure, mechanical and electrical properties of SiC-MoSi 2 -AlN composites was systematically investigated. A finer microstructure was obtained and electrical conductivity was enhanced with increasing MoSi 2 content. The impedance spectroscopy and potential-current measurements were implemented to figure out the electrical conduction mechanism. The introduction of MoSi 2 effectively reduced the Schottky barrier height at the grain boundary, and subsequently the U-I curves changed from nonlinear to linear electrical characteristics . The notable decrease in electrical resistivity was owing to the breakdown of grain boundaries and the formation of percolation paths. The percolation threshold was in the range of 0–5.44 vol% MoSi 2 , much lower than the reference value. The composites with 10 wt% MoSi 2 exhibited an electrical resistivity of about 60 Ω cm, suitable for infrared source element applications.
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2018
·Vol. 102
·期 1
·70-78
·
IF 2.956
Ping Hu,Yuan Cheng,Xiang Guo,Chen Ma,Peitao Hu,Qiang Qu,Hong Zhao,Shanyi Du
Inspired by grouting technique in architectural engineering, an innovative method of slurry injection and vacuum impregnation was put forward to introduce nanosized ZrC–SiC ceramics into PyC modified 3-D needle-punched carbon fiber preform homogeneously and continuously, followed by spark plasma sintering to prepare C f /ZrC–SiC with graceful mechanical responses. The composite possessed improved fracture toughness and work of fracture at 5.37 ± 0.25 MPa∙m 1/2 and 951 ± 12 J/m 2 , 50% and nearly one order of magnitude higher than those of ZrC–SiC composite, respectively, with rivaling flexural strength at 177 ± 8 MPa synchronously. A graceful fracture mode was embodied in an obviously extended yield plateau with increased failure displacement by 300%. This enhancement was attributed to the uniform and continuous combination of ZrC–SiC with carbon fiber preform as well as protection and interface tailoring from PyC coating. The study offered an easy and effective method of preparing 3-D fiber reinforced ceramic matrix composites.
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高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 20
·10999-11005
·
IF 7.443
Xunfu Zhou,Qiongzhi Gao,Xin Li,Yingju Liu,Shengsen Zhang,Yueping Fang,Jun Li
Herein, for the first time, ultra-thin SiC nanoparticles or ultra-thin layer covered graphene nanosheets were successfully prepared via using a facile in situ vapor–solid reaction. The samples were characterized by X-ray diffraction, UV-visible spectroscopy, photoluminescence spectra analysis, Raman spectra, transient photocurrent responses and transmission electron microscopy. The photocatalytic activities were also evaluated by H2 evolution from pure water or water containing Na2S as an electron donor. The resulting SiC–graphene hybrids show enhanced photocatalytic H2-evolution activities in the presence of an electron donor. Especially, the graphene nanosheet and SiC nanocrystal hybrids show the highest photocatalytic activity in H2 production under visible light, which is about 10 times higher than that of the SiC nanocrystals. The enhanced activities of the SiC–graphene hybrids can be attributed to their 2D nanosheet structures, large surface area, enhanced visible-light absorption and rapid interfacial charge transfer from SiC to graphene. Our results can provide an effective approach to synthesize graphene-based heterogeneous nanocomposites for a wide variety of potential applications in solar energy conversion and storage, separation, and purification processes.
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高影响因子
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Chi Zhang,Xiumin Yao,Yinsheng Li,Hanqin Liang,Jian Chen,Jingxian Zhang,Jian Yang,Xiaoyun Li,Tai Qiu,Zhongming Chen,Xuejian Liu,Zhengren Huang
Dense silicon carbide ceramics with 0.5–10 wt% AlN additions were pressureless densified by two steps sintering using B 4 C and C as sintering additives. The effects of AlN content on density, microstructure and thermal conductivity of SiC–AlN composites were investigated. SiC ceramics can be well densified in the presence of AlN. The phonon scattering mechanism and the Klemens–Callaway theory were used to calculate the thermal conductivity evolution of SiC ceramics result from the dissolved Al and N atoms. The main reason for the degradation of thermal conductivities is the point defect scattering dominated by the differences in size and interatomic forces between impurity and host atoms.
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高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2016
·
IF 1.34
Dong HUANG,Ming-yu ZHANG,Qi-zhong HUANG,Li-ping WANG,Xian TANG,Xin YANG,Kai TONG
A novel SiC–ZrB 2 coating was prepared using a two-step technique by slurry-sintering and chemical vapor reaction on carbon/carbon (C/C) composites. The SiC–ZrB 2 coating was composed of the scattered ZrB 2 phase and the continuous SiC phase. It was observed that a good adhesion was built between the coating and the C/C composites. The SiC–ZrB 2 coating samples exhibited a better ablation resistance in comparison with the uncoated C/C composites. The SiO 2 –ZrO 2 barrier layer, the heat dissipation of the gaseous products and the pinning effect of ZrO 2 all contributed to the good ablation resistance of the SiC–ZrB 2 coated composites.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Zahoor Ahmad,Jianjun Chen,Xiaohong Li,Hao Chen,Hafsa,Muhammad Arfan,Zaheer Hussain
SiC fiber-reinforced SiC ceramic matrix composites (SiC f /SiC CMCs) hold potential as thermal structural materials. In this work, SiC nanofibres were coated with multilayer interfaces by magnetron sputtering with the aim to tailor the fiber-matrix interface of SiC nanofibre reinforced SiC composites for superior mechanical properties. The influence of multilayer interface coating and sintering temperature on the density, microstructure, and mechanical properties of SiC nf /SiC CMCs fabricated via a hot-press technique employing ultra-long single-crystal SiC nanofibers as reinforcement were investigated. The composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and a universal testing machine. The prepared CMCs were toughened and strengthened by the observed fiber pull-out and bridging. The multilayered SiC nf /SiC CMCs with multiple interface coatings display an identifiable saw-tooth-like pattern in the load-displacement test, suggesting a significant improvement in the toughness of prepared materials through a laminated structure with weaker interface binding brought on by the thicker, denser coating. In comparison to the SiC nf /SiC composites without interface coating, the prepared SiC nf /SiC CMCs with PyC/SiAlC/ZrC interface layers revealed optimum flexural strength (520 ± 28.88 MPa, ↑46.5 %) and fracture toughness (9.95 ± 0.44 MPa m 1/2 , ↑94.7 %) after an hour of hot pressing at 1800 °C under pressure of 30 MPa. Besides an increase in relative density at high sintering temperatures (1850 °C), further grain coarsening deteriorated mechanical properties.
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高影响因子
危险品化学品经营许可证（带存储）