CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Yingjun Liu,Jianjun Sha,Cheng Su,Jixiang Dai,Yufei Zu
Sintering additive of ZrSi 2 is beneficial to low-temperature densification of ZrB 2 -based ultra-high temperature ceramics (UHTCs), nevertheless, residual ZrSi 2 would severely reduce the high-temperature strength of UHTCs. In the current work, to achieve low-temperature preparation of ZrB 2 -based UHTCs with good high-temperature strength, active carbon (C) was added into ZrB 2 –ZrSi 2 ceramics to convert the sintering additive into refractory phases of SiC/ZrC. C-doped ZrB 2 –ZrSi 2 powders were hot-pressed at different temperatures to investigate the phase composition, microstructure and densification behavior. TG-DSC, XRD and SEM results indicated that ZrSi 2 was almost entirely converted into SiC and ZrC at 1600 °C for 2h, meanwhile, a fully-dense C-doped ZrB 2 –ZrSi 2 ceramic was obtained at such sintering conditions. In addition, the high-temperature (1800 °C) strength of C-doped ZrB 2 –ZrSi 2 ceramic was 390 ± 21 MPa, which was much higher than that of the C-undoped one. The excellent high-temperature mechanical properties could be attributed to the transformation of low-melting-point phases into refractory phases.
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
·
2023
·
IF 5.2
Zhangyi Huang,Jiaochun Zheng,Mingyu Su,Mao Deng,Yang Shi,Ruichong Chen,Qingyuan Wang,Zhijun Wang,Jianqi Qi,Rui Li,Haomin Wang
Densifying transition metal carbide (TMC) ceramics is challenging due to their low diffusion coefficient and strong covalent bonding. Ultra-high-pressure sintering (UHPS) is a promising technique for preparing dense ceramic materials at low temperatures, but it is underutilized in TMC ceramics. Herein, we report the successful employment of UHPS at 1500 °C for 3 min with an auxiliary pressure of 7 GPa, yielding TaC, NbC, TiC, and ZrC ceramics with relative densities of 99.3%, 98.9%, 98.2%, and 96.4%, respectively. We demonstrate that the densification mechanism of the TMC ceramic in this investigation encompasses plastic deformation and high-pressure assisted atomic diffusion. Furthermore, we determine the Vickers hardness and fracture toughness of TaC, NbC, TiC, and ZrC ceramics to be 16.5, 15.9, 24.0, and 17.7 GPa and 2.5, 2.9, 2.8, and 1.8 MPa m 1/2 , respectively. Moreover, with increasing temperature from room temperature to 500 °C, the hardness and elastic modulus of all four TMC ceramics gradually decrease, with the hardness declining by approximately 17–25%.
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
Nano Research
·
2023
·
IF 9.9
Wu Kunjie,Wang Bin,Niu Yutao,Wang Wenjing,Wu Cao,Zhou Tao,Chen Li,Zhan Xianghe,Wan Ziyao,Wang Shan,Yang Zhengpeng,Zhang Yichi,Zhang Liwen,Zhang Yongyi,Yong Zhenzhong,Jian Muqiang,Li Qingwen
Floating catalysis chemical vapor deposition (FCCVD) direct spinning process is an attractive method for fabrication of carbon nanotube fibers (CNTFs). However, the intrinsic structural defects, such as entanglement of the constituent carbon nanotubes (CNTs) and inter-tube gaps within the FCCVD CNTFs, hinder the enhancement of mechanical/electrical properties and the realization of practical applications of CNTFs. Therefore, achieving a comprehensive reassembly of CNTFs with both high alignment and dense packing is particularly crucial. Herein, an efficient reinforcing strategy for FCCVD CNTFs was developed, involving chlorosulfonic acid-assisted wet stretching for CNT realigning and mechanical rolling for densification. To reveal the intrinsic relationship between the microstructure and the mechanical/electrical properties of CNTFs, the microstructure evolution of the CNTFs was characterized by cross-sectional scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), polarized Raman spectroscopy and Brunauer–Emmett–Teller (BET) analysis. The results demonstrate that this strategy can improve the CNT alignment and eliminate the inter-tube voids in the CNTFs, which will lead to the decrease of mean distance between CNTs and increase of inter-tube contact area, resulting in the enhanced inter-tube van der Waals interactions. These microstructural evolutions are beneficial to the load transfer and electron transport between CNTs, and are the main cause of the significant enhancement of mechanical and electrical properties of the CNTFs. Specifically, the tensile strength, elastic modulus and electrical conductivity of the high-performance CNTFs are 7.67 GPa, 230 GPa and 4.36 × 10 6 S/m, respectively. It paves the way for further applications of CNTFs in high-end functional composites.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Australian Ceramic Society
·
2023
·Vol. 59
·期 5
·1231-1239
·
IF 1.9
Zhang Mengwen,Jiang Binyang,Yang Lutong,Cao Na,Li Zhaosheng,Fan Lei,Yang Shoulei
The emerging oscillatory pressure sintering technology is used to prepare high-performance Al 2 O 3 -Ti(C,N) ceramic tools for high-speed cutting. By recording the displacement during sintering, the sintering shrinkage rate of the Al 2 O 3 -Ti(C,N) composite was calculated, and the stress exponent n and sintering activation energy Q were calculated according to creep theory to determine the densification mechanism. In addition, the evolution of phases, microstructure and hardness of the composite was also observed. Results show that during oscillatory pressure sintering process at 1400 °C and 1300 °C, the stress exponent of Al 2 O 3 -Ti(C,N) composite is around 2.2 and the sintering activation energy is 486 kJ mol −1 , indicating that the densification mechanism is a diffusion-controlled grain boundary sliding of Al 2 O 3 phase. Additionally, as the oscillatory pressure increases, the average grain size of the Al 2 O 3 decreases and the Vickers hardness increases. Hardness achieves the highest 22.7 GPa when the median oscillatory pressure is 70 MPa at 1400 °C, which is 1 GPa higher than that of static pressure of 70 MPa.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2023
·
IF 8.7
Xiaoxiao Wei,Wei Chen,Huan Ma,Xiaori Yang,Wei Liu,Zhihan Zhang,Fujun Xu
Carbon nanotube yarns (CNTY) have the potential to serve as continuous reinforcement in functional-structural composite materials; however, there exists the insulation problem (or poor conductivity) of polymers that has hampered the development of CNT/polymer-based composite electronic devices. Herein, a strategy is proposed to develop CNT/polymer-based composite yarn with excellent electrical and mechanical properties by doping polyethyleneimine (PEI) polymer and then directional densification-stretching. The PEI polymer was well-infiltrated into intra- and inner CNT bundles to construct a consecutively conductive pathway, endowing an ultra-robust tensile strength (∼1207 MPa) and highly electrical conductivity (2.1 × 10 3 S cm −1 ) of composite yarn. The resulting CNT/PEI CYs also exhibit integrated performances of superior mechanical damping, anti-abrasive ability, extreme environment stability, and electrothermal properties. Additionally, they can act as stretchable conductors to maintain electrical stability during large-strain (100%) cyclic stretching. This engineering strategy provides novel insights into the development of continuous CNT/polymer-based composites for structural and functional composite materials .
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
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Zhipeng Zhu,Xiaoxue Song,Xiang Chi,Jingyao Zhao,Qiaofang Zhou,Antoni Sanchez‑Ferrer,Dengyun Tu,Wanli Cheng
Unilateral surface compression in wood presents notable benefits, including reduced wood volume loss and energy consumption, rendering a highly promising and extensive utilization. However, shortcomings in compressed wood arise due to unclear gas pressure, temperature, and moisture content distribution within the wood during hot pressing. In this paper, the temperature and pressure distribution were analyzed utilizing an optical fiber temperature and pressure measurement system within the wood during hot pressing. Moreover, the moisture content, stress and strain in each layer at the end of hot pressing were discussed extensively. The results showed that the wood surface layer (SL) and subsurface layer (SSL) maximum temperature values were similar even with different layer thicknesses. Under sealing conditions, SL and SSL temperatures were generally 6 ℃ to 7 ℃ higher compared to unsealing conditions. The gas pressure maximum value exhibited an opposite order, gradually transferring to the core layer (CL) and declining as the processing time extended. During compression treatment, moisture migrated from the hot end to the cold within the wood. The moisture content displayed significant differences between the middle and end parts of the wood under unsealed conditions, with the disparity becoming more pronounced further away from the hot end. The transition region of the compressed wood served as a stress concentration area, experiencing the highest levels of stress. The dense region followed with the second highest stress levels, while the un-densified region exhibited the least amount of stress. Under the same process parameters, the thickness had little influence on the distribution of dense layers.
研究领域:
木材科学
·
材料科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Wanhong Yu,Guifang Li,Changwan Sun,Jianquan Zhang,Li Yang,Yichun Zhou
In this paper, we propose an effective method for doping WC into Ta-Hf-C ceramics to significantly enhance their densification and mechanical properties. An increasing WC doping amount from 0 to 20 at.%, enhances the densification of Ta-Hf-C ceramics from 92.4 % to 99.1 %. This is mainly due to the fact that the doping of WC effectively removes the harmful oxygen impurities from the ceramics, thereby increasing their sintering activity. Furthermore, the doping of WC plays an active role in the mechanical properties of the ceramics. The Ta-Hf-C doped with 15 at.% WC has the highest value of 36.41 GPa for nano-hardness due to the solid solution strengthening mechanism, while the highest Vickers hardness (38.75 GPa) and fracture toughness (3.76 MPa m 1/2 ) appear in Ta-Hf-C doped with 20 at.% WC. The main toughness mechanism is W segregation at the grain boundary, enhancing grain boundary strength .
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Fang Xu,Dainan Zhang,Gang Wang,Huaiwu Zhang,Yan Yang,Yulong Liao,Lichuan Jin,Yiheng Rao,Jie Li,Fei Xie,Gongwen Gan
NiCuZn ferrite ceramics with high permeability and low magnetic loss have great values in high frequency applications. Here, we synthesized uniform and compact NiCuZn ferrites with small grains (about 1.5 μm) at 875 ° C via adjusting additive amount of Nb 2 O 5 and Bi 2 O 3 . The influence of Bi 2 O 3 additives on the microstructure and magnetic properties of NiCuZn ferrite, especially for grain growth and grain size, have been investigated. SEM results indicated that Nb 2 O 5 can obviously suppress grain growth when a small amount of Bi 2 O 3 was added. Also, the liquid phase of Bi 2 O 3 only can promote movement of grain boundary and reduce porosities between grains. Thus, a NiCuZn ferrite with high permeability ( μ i ′ = 472.79), high saturation flux density ( B s = 0.313 T), high Q value (66.3) and low coercivity ( H c = 94.75 A/m) was obtained when 0.25 wt % Nb 2 O 5 -0.50 wt % Bi 2 O 3 was added. It is proved that improvement of compactness can enhance magnetic properties even though grain growth was suppressed. However, over much Bi 2 O 3 (more than 1.00 wt %) reduced the magnetic properties due to deterioration of grains uniformity and existence of non-magnetic Bi 2 O 3 liquid phase. Such a low temperature solid phase synthesis method (i.e., adding composite additive with different melting point oxide) should also facilitate preparation of other advanced ceramics for practical applications.
研究领域:
材料科学
·
磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2026
·Vol. 46
·期 16
·118692
·
IF 6.3
Chengfan Yuan,Qiang Gao,Xinhui Geng,Wuju Wang,Liancai Xun,Puzheng Zhang,Ping Hu
C/SiC composites known for excellent high-temperature resistance and favorable mechanical properties are promising thermal protection materials. However, pores and microcracks from traditional processes significantly degrade their high-temperature oxidation resistance. Herein, we propose an integrated technique that combines coating preparation with matrix densification. Using this approach, a uniform SiC coating (50 μm thickness) was successfully prepared on C/SiC composites, while simultaneously achieving matrix densification. SiC-C/SiC composites exhibited superior oxidation resistance at 1000–1600 ℃. After 1600 ℃ oxidation, the mass loss rate decreased from 16.8% to 6%, and flexural strength (246 ± 24 MPa) was 2.5 times that of C/SiC composites (91 ± 37 MPa). Additionally, SiC-C/SiC composites demonstrated excellent oxidation and ablation resistance at 1600–1800 ℃ compared with conventional C/SiC composites. This technique allows component design to be tailored to practical requirements, providing a feasible method for efficient preparation of coatings.
✓ 已验证
产品关联
DOI
高影响因子
WOOD SCIENCE AND TECHNOLOGY
·
2026
·Vol. 60
·期 6
·89
·
IF 3.2
He Jianmin,Bai Zhongyang,Cui Xinru,Pan Yuzhen,Hu Yingcheng
Wood, a sustainable building material, faces limitations due to its inherent low mechanical strength and flammability. This study develops a biodegradable, high-strength, and flame-retardant wood composite through a synergistic strategy combining sodium alginate-induced biomimetic mineralization of calcium carbonate with physical densification. The resulting material achieves a limiting oxygen index of 31.5%, meeting the standard for high-performance flame-retardant materials. Its specific modulus reaches 28.26 GPa·cm³·g⁻¹, surpassing that of aluminum. Notably, cone calorimetry analysis reveals a synergistic suppression of smoke production. Environmental evaluations confirm the composite retains excellent biodegradability and exhibits low ecotoxicity. Utilizing industry-compatible processes and low-cost raw materials, this approach offers a scalable and practical pathway for producing advanced bio-based construction materials.
✓ 已验证
DOI
高影响因子
Applied Materials Today
·
2026
·
IF 7
Zijun Yan,Yue Sun,Yurong Dai,Shuhui Wang,Guolong Chen,Yue Lin,Huanhua Wang,Hao-Chung Kuo,Zhong Chen,Tingzhu Wu
Atomic layer deposition (ALD) presents a promising avenue for improving the environmental stability of perovskite quantum dots (PQDs). However, standard ALD processes (120–200 °C) inevitably compromise the PQD lattice structure, while lower temperatures yield porous, non-protective films. To overcome this trade-off, we developed a sequential-temperature ALD strategy that synergizes low-temperature surface passivation with high-temperature densification. First, a low-temperature (65 °C) ALD stage deposits a surface modification layer around PQDs, which leverages energetic precursor molecules to selectively passivate surface/lattice defects, effectively suppressing non-radiative recombination within PQDs and boosting their luminescence efficiency. Crucially, this initial layer plays a pivotal role in preventing thermal degradation of the perovskite during subsequent processing and generates a hydroxyl‑rich surface. These reactive sites facilitate the second stage, a high-temperature (120 °C) ALD, to rapidly deposit a dense Al 2 O 3 protective barrier layer. Remarkably, this sequential process induces the formation of a chemically graded Pb–O–Al–O–Al 2 O 3 interfacial structure remediating defects within the initial layer, exhibiting intrinsic self-healing capability. The resulting CsPbBr 3 /Al 2 O 3 composite manifests exceptional environmental stability, particularly against moisture, representing one of the best performances reported to date for ALD-encapsulated bulk CsPbBr 3 films. Unlike complex hybrid encapsulation schemes, our streamlined, standalone ALD approach enables scalable PQD modification. White light-emitting diodes fabricated with these encapsulated PQDs demonstrate a wide color gamut (∼120% NTSC) and remarkable spectral stability. This work establishes a generalizable paradigm for ALD encapsulation of thermally sensitive materials.
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2026
·
IF 2.6
Xinyuan Wan
Structural colors derived from chiral nematic cellulose nanocrystals (CNCs) hold great promise for sustainable photonics; however, their practical applications are severely impeded by intrinsic mechanical brittleness and extreme vulnerability to environmental hazards, particularly moisture and fire. Herein, we report an ultrastrong, superamphiphobic, and flame-retardant biomimetic composite film designed to fundamentally break this longstanding optical-mechanical trade-off. By encapsulating a fragile CNC photonic core between two robust, highly aligned cellulose nanofibril (CNF) skins derived from natural wood, a synergistic high-pressure densification strategy is employed to reconstruct the mechanical framework. The resulting "sandwich" composite not only perfectly preserves vibrant, tunable macroscopic iridescence but also achieves an unprecedented tensile strength of 474.4 MPa and a remarkable toughness of 21.15 MJ m-3—representing staggering ~50-fold and ~190-fold enhancements over pure CNC films, respectively. Furthermore, the integration of a hierarchical multiscale coating (F-FC-APP/SiO2) endows the composite with robust superamphiphobicity (contact angles >150° for water and varied oils) and excellent self-extinguishing flame retardancy. This rational structural and interfacial engineering strategy effectively shields the photonic core from physical and environmental degradation, paving a sustainable pathway for the deployment of durable, multifunctional structural color materials as eco-friendly alternatives to toxic chemical dyes in demanding optical, decorative, and load-bearing applications.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）