Advances in Applied Ceramics
·
2025
·
IF 1.6
Maohui Li,Mingjun Zhang,Bo Ma,Wenzhou Sun,Yanmin Wang,Youjun Lu
The brittleness of silicon carbide restricts its wide application. Graphene as a superior second-phase material can improve the toughness and brittleness of silicon carbide. In this article, a graphene/β-SiC ceramic material was prepared with 1–3 wt.% graphene added in β-SiC matrix via pressure-free sintering at 2120°C for 60 min. The effect of the graphene addition on the phase composition, bulk density, porosity, and mechanical properties of ceramic material was investigated. The results show that the bulk density of graphene/β-SiC ceramic material decreases, the porosity of openings increases, and the bending strength, hardness, as well as fracture toughness firstly increase and then decrease as graphene addition increases. Compared with β-SiC ceramic without graphene, the optimum properties of graphene/β-SiC ceramic with graphene addition of 1 wt.% (i.e. a fracture toughness of 5.07 MPa m1/2, bending strength of 410.84 MPa and hardness of 27.72 HV) can be obtained, which are increased by 35.56%, 13.35%, and 3.8%, respectively. The fracture morphology indicates that the crack deflection is the main mechanism of toughening β-SiC ceramic with graphene.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Xiao-Dong Jian,Biao Lu,Dan-Dan Li,Ying-Bang Yao,Tao Tao,Bo Liang,Xiong-Wei Lin,Jin-Hong Guo,Yi-Jiang Zeng,Sheng-Guo Lu
Barium strontium zirconate titanate ceramics ((BaSr)(ZrTi)O3-BSZT) with Zr4+ ionic contents of 15 and 20 mol % and Sr2+ ionic contents of 15, 20, 25, and 30 mol % were prepared using a solid-state reaction approach. X-ray diffraction and scanning electron microscopy were used to characterize the lattice structure and morphologies of the ceramics. Permittivity and polarization as a function of temperature were characterized using an impedance analyzer and a Tower–Sawyer circuit. The electrocaloric effect was measured directly and calculated using the Maxwell relation (indirectly). The results indicated that the BSZT ceramics change from a normal ferroelectric to a relaxor ferroelectric with increasing Zr4+ ionic content, which can be further modified by the addition of Sr2+ ionic content. The optimized adiabatic temperature change ΔT obtained is 2.43 K in (Ba0.85Sr0.15)(Zr0.15Ti0.75)O3 ceramics, and ΔT >1.6 K over a wide temperature span of 120 °C was obtained.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Zili Liu,Chong Wei,Yueying De,Songbin Zhang,Cheng Zhang,Xiaoqiang Li
High-entropy pyrochlore ceramics have received significant attention in the field of nuclear materials due to their ability to immobilize radioactive waste . In this study, a range of medium and high-entropy Ti-based pyrochlore powders were synthesized by a two-step method. Interestingly, a monoclinic phase was observed in some powders. An innovative experiment was conducted to adjust the cation ratio at the A site, which revealed that certain cations with larger ionic radii exhibit low solid solubility in the pyrochlore lattice, resulting in the formation of the monoclinic structure. To avoid the formation of monoclinic phase, the crystal structure was adjusted by introducing Zr 4+ at the B site. Based on the selection of single-phase powders, high-density pyrochlore ceramic bulks with uniform distribution of elements were prepared by spark plasma sintering . Here (Sm 1/5 Yb 1/5 Gd 1/5 Er 1/5 Dy 1/5 ) 2 Ti 2 O 7 bulks exhibited the smallest grain size at approximately 2.48 µm among all sintered samples and demonstrated a hardness of around 10.14 GPa.
研究领域:
核材料科学
·
无机材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Zhenhui Zhang,Xiangluo Miao,Xiangbin Zhang,Shibang Zhang,Changan Wang,Deyang Chen,Min Zeng,Xingsen Gao
NaNbO 3 (NN)-based ceramics have received a great deal of attention for the potential application in dielectric energy storage capacitors. However, the energy storage properties (ESP) remain low, particularly under moderate electric field. Herein, a Bi-rich doping unit of BiMg 2/3 Nb 1/3 O 3 (BMN) was introduced into a 0.85NaNbO 3 -0.15Bi 0.1 Sr 0.85 TiO 3 (NN-SBT) matrix, aiming to improve polarization along ESP. As a result, a large recoverable energy density ( W rec ) of ∼6.1 J/cm 3 and an efficiency ( η ) of ∼81 % were achieved in NN-SBT-0.08BMN ceramics under a moderate electric field of 337 kV/cm. The improved ESP can be attributed to the introduction of BMN, which delays the polarization saturation of NN-SBT ceramics, while maintaining the maximum polarization (∼43.6 μC/cm 2 ), and generating polar nanoregions (PNRs). Moreover, the optimal ceramics exhibited good thermal (25–130 °C) and frequency (1–300 Hz) stabilities, and fatigue endurance (>10 5 cycles). These results illustrate that the designed NN-SBT-0.08BMN ceramics are promising for application in dielectric energy storage capacitors with high ESP under a moderate electric field.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE FORUM
·
2015
·
IF 0
Gang Chen,Chun Wei Gong,Chun Lin Fu,Xiao Dong Peng,Wei Cai,Rong Li Gao,Xiao Ling Deng
(Sr1-xBax) 2(Nb0.9Ta0.1) 2O7 (SBNT) ceramics were prepared by solid state reaction. The crystal structure of SBNT ceramics, surface morphology and dielectric properties were studied using XRD, SEM and LCR instrument analyzer, respectively. The results show that the grain size decreases with increasing Ba concentration, and all samples show single phase, no second phase can been observed. Addition of Ba ion can improve the dielectric properties of SBN ceramics. The dielectric constant increases first, then decreases; the maximum value (εr=97) can be obtained at x=0.1, the dielectric constant changes slightly with increasing wide frequency.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Y.K. Yang,H.L. Pan,H.T. Wu
Li 2 Mg 3 Ti 1-X (Mg 1/3 Nb 2/3 ) X O 6 (0 ≤x ≤ 0.25) ceramics were prepared by a conventional solid-state reaction process. Their crystal structures, sintering characteristics, Raman spectra and microwave dielectric properties were then investigated. XRD patterns of the sintered samples indicated that all compositions showed a single phase and the rock-salt structure. As the (Mg 1/3 Nb 2/3 ) 4+ contents increase, the variations of ε r values showed a downward trend, which could be explained by the changes of polarizabilities and the shift of Raman vibration modes. Q·f values initially increased to a maximum value and then decreased with increasing of x values. In addition, τ f values decreased almost linearly with the x values, which significantly correlated with the thermal expansion coefficient. Excellent combined microwave dielectric properties with ε r = 14.79, Q·f = 204,900 GHz and τ f = −18.43 ppm/°C were obtained for Li 2 Mg 3 Ti .95 (Mg 1/3 Nb 2/3 ) .05 O 6 ceramic sintered at 1550 °C.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zhuojia Xie,Zhengguang Zou,Xinyu Jiang,Weijian Zhang
The effects of K + doping on structure, magnetic characteristics , magnetocaloric properties, and critical behavior of La 0.7-x Nd 0.1 Sr 0.2 K x Mn 0.95 Ni 0.05 O 3 (LNSKMNO) ceramics (x = 0.00, 0.05, and 0.10) were investigated. The X-ray diffraction and refinement findings revealed that LNSKMNO exhibited a distinctive rhombohedral structure of the R-3c space group (No. 167). To validate the chemical composition of LNSKMNO ceramics, EDS spectroscopy and X-ray photoelectron spectroscopy (XPS) were utilized. The magnetization of LNSKMNO exhibited a temperature-dependent behavior, revealing a phase transition from the ferromagnetic (FM) phase to the paramagnetic (PM) phase at approximately the Curie temperature (Tc). By utilizing normalization and Banerjee's criterion, the magnetic phase transition of LNSKMNO was determined to be a second order magnetic phase transition. The maximal magnetic entropy ( − Δ S M max ) of LNSKMNO around Tc was 4.24, 4.53, and 4.07 J/(kg K) at the 5 T external magnetic field (H). The Kouvel-Fisher approach and modified Arrott plot were used for determining the values of the critical exponents of β , γ , and δ . The critical exponents for LNSKMNO ceramics generally conformed to those obtained based on the Mean-field model.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
FERROELECTRICS
·
2014
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IF 0.433
Lian Xiang,Gang Chen,Chunlin Fu,Wei Cai,Wei Wang,Kaihua Liu
Sr2(TaxNb1-x)2O7 (x = 0.0, 0.1, 0.2, 0.4) (STNO) ceramics were prepared by the conventional solid-state reaction method. The microstructure, dielectric and ferroelectric properties of the samples were investigated. The results show single phase STNO with perovskite-like layered structure and that Ta5+ ion can diffuses into the crystal lattice. The addition of Ta5+ dopant decreases the grain size of the material. The dielectric constant increases with increased x, and the sample with x = 0.2 exhibits enhanced dielectric properties (ϵr ≈ 56, tanδ ≈ 0.01%). The remnant polarization (2Pr) and coercive electric field (2EC) of STNO ceramics increase with increasing Ta content, and reach the maximum value (2Pr = 0.11μC/cm2 and 2EC = 5.75 kV/cm) at x = 0.4. Our results indicate that Ta doping can effectively improve the dielectric and ferroelectric properties of Sr2Nb2O7 ceramics.
研究领域:
材料科学
·
电子材料
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Zhiqiang Zhang,Fan Zhang,Yiwen Niu,Meiyue Li,Jihang Liu,Zhan Jie Wang
Dielectric capacitors typically require high electric fields to achieve excellent energy storage density, which limits the integration, miniaturization, and lifespan of energy storage devices. Therefore, it is essential to obtain good energy storage properties at a lower electric field. In this study, (Ag 0.94 La 0.02 )(Nb 0.85 Ta 0.15 )O 3 (ALNT)-modified (Bi 0.5 Na 0.5 )TiO 3 -based ceramics with improved energy storage characteristics were designed and prepared. The introduction of ALNT is conducive to optimizing the polarization, adjusting the phase composition, disrupting the long-range ferroelectric ordering, and enhancing the dielectric relaxation behavior, leading to an increase in the polarization difference. Accordingly, superior recoverable energy storage density of 3.07 J/cm 3 and high efficiency of 82.7% are synchronously realized under a lower electric field of 150 kV/cm in a 5 mol% ALNT system. In addition, the corresponding sample exhibits wide thermal (40–100°C) and frequency (10–100 Hz) stability and good charge–discharge properties. This study provides a new candidate material for advanced dielectric capacitors that can be applied in lower electric fields.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 100
·期 10
·4412-4424
·
IF 2.841
Jingkun Yuan,Peigang He,Dechang Jia,Jinsong You,Xuzhao Liu,Yao Zhang,Delong Cai,Zhihua Yang,Xiaoming Duan,Shengjin Wang,Yu Zhou
As part of a series of studies, effects of Na + substitution on the thermal evolution of cesium-based geopolymers on heating were studied. A series of sodium-substituted cesium-based geopolymers, Cs (1− x ) Na x GPs (where x =0, 0.1, 0.2, 0.3, and 0.4), were prepared and treated at 1300°C for 2 hours to obtain the corresponding ceramic products. The thermal evolution process was disclosed by virtue of a variety of technical, including TG-DTA, thermal shrinkage, XRD analysis, SEM, and TEM investigation. The results indicated that unheated Cs (1− x ) Na x GPs was not completely amorphous after the substitution of Na + and the crystallinity of Cs (1− x ) Na x GPs gradually increased with the rise of sodium content. Meanwhile, the average particle sizes of Cs (1− x ) Na x GPs also increased evidently with increases in sodium substitution. The final product after heat treatment mainly consisted of pollucite (CsAlSi 2 O 6 ) and amorphous glass phase. The particle size of pollucite grain gradually decreased as more Cs + were replaced maybe owing to the role of Na + in the nucleation process of pollucite. Two forms of Na + present in the final products: A small portion was present in the pollucite grains due to Na + partial occupied the crystallographic sites of Cs + ; and the rest were present in the amorphous glass phase among the pollucite grains. The average coefficient of thermal expansion (CTE) of resulting Cs (1− x ) Na x GPs ceramics increased from 4.80×10 -6 K −1 ( x =0) to 7.26×10 −6 K −1 ( x =0.4) with increases in sodium substitution, which could be due to the amorphous glass phase had a relatively higher CTE than that of pollucite.
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
Additive Manufacturing
·
2022
·
IF 11.632
Shufeng Xiong,Jian Liu,Jiwei Cao,Ziyong Li,Muhammad Idrees,Xiao Lin,Zhongyu Long,Zhiyuan Liu,Pei Wang,Changyong Liu,Zhangwei Chen
Previous research often failed to prepared polymer-derived SiOC ceramic components with dense and thick monoliths/skeletons based on additive manufacturing processes, due to the porosities and cracks generated during the pyrolysis process . Herein, we report a simple solution which combines the introduction of phenolic resin (PR) as an additive and the use of controlled strategy of pyrolysis, for the vat photopolymerization additively manufactured SiOC ceramics. As a result, crack-free dense monolith and lattice skeleton structural polymer-derived SiOC ceramics are successfully prepared despite the low ceramic yield of 19.3 wt% and large linear shrinkage of 50% generated after pyrolysis. The prepared dense monoliths possess a thickness of over 5 mm and the lattices show attainable maximum dense skeletons thickness of ~2 mm. The maximum dense thickness of the samples after pyrolysis is over 7 times that of other samples prepared based on additive manufacturing reported in the literature. As an indicator of dimensional retention, the specific dense thickness to ceramic yield ratio (T/Y) is deduced, resulting maximum values of 101.9 µm/(wt%) for lattice skeletons and 254.7 µm/(wt%) for monoliths. The former is even larger than that for dense monolith SiOC structures prepared by other conventional gel casting and isostatic pressing techniques with much higher ceramic yields of > 80 wt%, and is about 6.1 times the largest T/Y ratio (=16.7 µm/(wt%)) achievable in the AM-based works reported in the literature. This shows predominance of the current work over other types of polymer-derived ceramic structures prepared by additive manufacturing and even conventional methods. The lattice structures’ apparent density and specific strength reached 0.55 g/cm 3 and 6.6 × 10 4 N∙m/kg, respectively. The mechanical performance surpasses other structural polymer-derived ceramic structures with similar apparent density reported in the literature. Through the advanced characterization and analysis of material phase and morphology evolution during the pyrolysis process, the mechanism of defect-free densification is revealed. That is, the introduction of PR enables a highly smooth gas-releasing process due to the generation of ordered gas-releasing channels in the sample bodies during the pyrolysis process. As a result, the generation of cracks and defects was successfully prevented. Moreover, due to the high carbon residue of the PR, the samples containing 15 wt% PR in the preceramic state still possessed amorphous SiOC ceramics after pyrolysis at 1400 ℃, while 0 wt% PR samples showed SiC crystallization. Compared with similar materials reported, the ceramics prepared in this study exhibit enhanced structural and mechanical performance. The strategy investigated in the study can be a viable route for the additive manufacturing of high-performance crack-free and thick monolith and lattice skeleton SiOC ceramic structures based on vat photopolymerization.
研究领域:
材料科学
·
制造工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Bin He,Wuwei Feng,Meitang Liu,Jigong Hao,Hong Zheng,Yuqin Liu,Shuo Liu,Cheng Hu,He Qi
Herein, NaTaO 3 (NT) is introduced into 0.7Bi 0.5 Na 0.5 TiO 3 -0.3 Sr 0.7 La 0.2 TiO 3 (BNSLT) ceramic to increase the content of the highly stable P4bm phase, constructing a temperature-insensitive phase structure and permittivity over a wide temperature range (25–300 °C); thus, excellent thermal stability ( W rec = 4.68 ± 0.50 J/cm 3 , η = 89.0 ± 2.1%) over an ultra-wide temperature range (20–240 °C) is realized, superior to most lead-free ceramics. The co-substitution of heterovalent ions at both A and B sites in BNSLT leads to enhanced relaxor state and bandgap, delayed saturation polarization, reduced grain size and permittivity. Thereby, an excellent recoverable energy storage density ( W rec = 8.55 J/cm 3 ), high efficiency ( η = 89.5%), and extremely high power density ( P D = 320 MW/cm 3 at 280 kV/cm) are obtained in BNSLT-8%NT ceramics. This work offers a new paradigm for the development of ceramic capacitors with both excellent comprehensive energy storage performance and high-temperature working stability.
研究领域:
材料科学
·
电子工程
✓ 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）