CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yu Wang,Zhi-Bo Li,Kai-Fei Wang,Guo-Hua Zhang
Tungsten borides are special compounds with potential applications in superhard materials, anti-friction materials, and catalytic materials. In this study, a new synthetic method for tungsten boride is proposed using tungsten (W) and boron carbide (B 4 C) as raw materials. First, the boronization reaction between W and B 4 C was carried out at a high temperature; then, the boronization products were reacted with calcium to generate CaC 2 for decarburization. After acidic leaching of the CaC 2 and Ca, pure tungsten boride could be prepared. By investigating the reaction between different ratios of W and B 4 C, it was found that only pure W 2 B and WB were synthesized in the current method, and W 2 B 5 could react rapidly with Ca to form WB and CaB 6 . However, in the absence of a decarburization treatment after the boronization process, carbon-containing WB (C content = 1.2 wt%) and W 2 B 5 (C content = 3.4 wt%) could also be prepared. In addition, it was concluded that the prepared tungsten boride roughly maintained the morphology and particle size of raw W, and ultra-fine tungsten boride could be synthesized with ultra-fine W powder at a low boronization reaction temperature.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 4
·2399-2406
·
IF 3.094
Yu Wang,He Zhang,Shuqiang Jiao,Kuo-Chih Chou,Guo-Hua Zhang
Molybdenum boride is an ideal hard and wear-resistant material. In this study, a new method is proposed for preparing molybdenum boride, by which Mo first reacts with B 4 C to generate the mixture of molybdenum boride and C, and then the product is decarburized by molten Ca to generate CaC 2 . Pure molybdenum boride could be obtained after acid leaching to remove the by-product CaC 2 . According to the experimental and thermodynamic calculation results, it is concluded that the single-phase MoB could be successfully prepared, while Mo 2 B, Mo 2 B 5 , and MoB 4 could not be synthesized by this method. Moreover, it was found that the particle size of finally prepared MoB is determined by particle size of raw Mo powder. The residual carbon content of the product could be decreased to 0.10 wt% after first reaction at 1673 K for 6 hours and then decarburization reaction at 1673 K for 6 hours.
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
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 101
·期 3
·1289-1297
·
IF 2.841
Lixin Liu,Xuhai Li,Qiang He,Liang Xu,Xiuxia Cao,Xusheng Peng,Chuanmin Meng,Wenqiang Wang,Wenjun Zhu,Yuan Wang
Traditionally, densification and grain growth are two competing processes in sintering of ceramics. To improve the density, while limiting grain growth at the same time, an ultrahigh pressure (>1 GPa) is employed here and results in plastic deformation as the dominant densification mechanism during the sintering process. In this way, fully dense boron carbide (B 4 C) structural ceramics without grain growth is prepared under the pressure of 4.5 GPa at low temperature of 1300°C in 5 minutes, while showing excellent mechanical properties such as Vickers hardness of 38.04 GPa, Young's modulus of 487.7 GPa, and fracture toughness of 3.87 MPa·m 1/2 . This study should also facilitate the development of other structural ceramics for practical applications.
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
Materials
·
2024
·Vol. 17
·期 23
·5838
·
IF 3.1
Xiaonan Wang,Dianzhen Wang,Kaixuan Rong,Qiang Tao,Pinwen Zhu
Introducing a second phase has been an effective way to solve the brittleness of boron carbide (B4C) for its application. Though reduced graphene oxide (rGO) is an ideal candidate for reinforcing the B4C duo’s two-dimensional structure and excellent mechanical properties, the toughness is less than 6 MPa·m1/2, or the hardness is lower than 30 GPa in B4C–graphene composites. A barrier to enhancing toughness is the weak interface strength between rGO and B4C, which limits the bridging and pull-out toughening effects of rGO. In this work, internal stress was introduced using a high-pressure and high-temperature (HPHT) method with B4C–rGO composites. The optimal hardness and toughness values for the B4C-2vol%rGO composite reached 30.1 GPa and 8.6 MPa·m1/2, respectively. The improvement in toughness was 4 times higher than that of pure B4C. The internal stress in the composite increased gradually from 2.3 GPa to 3.3 GPa with an increase in rGO content from 1vol%to 3vol%. Crack deflection, bridging, and rGO pull-out are responsible for the improvement in toughness. Moreover, the high internal stress contributed to the formation of good interface strength by embedding rGO into the B4C matrix particles, which further enhanced the dissipation of the crack energy during the pull-out process and led to high toughness. This work provides new insights into synthesizing high-toughness B4C matrix composites.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jidong Zhang,Xuexi Zhang,Mingfang Qian,Junjian Zhou,Zhenggang Jia,Lin Geng
Nacre-inspired (TiBw-TiB 2p )/2024Al aluminum-matrix composites (AMCs) were fabricated using the pressure infiltration of molten Al into a porous TiBw-TiB 2p preform obtained by ice templating. Hot extrusion (475–520 °C) was utilized to control the nacre-inspired architecture and tailor the tensile properties of the nacre-inspired AMC. The continuous ceramic-rich layers transitioned to quasi-continuous ones after hot extrusion. As the extrusion temperature increased, the thickness of the ceramic-rich and Al layers decreased from 27.2 and 25.4 μm in the cast composite to 12.8 and 11.6 μm, respectively, in the composite extruded at 520 °C. The Al composite extruded at 520 °C exhibited an optimal balance between strength and ductility, with tensile strength and elongation reaching 470.5 MPa and 1.9 %, respectively, which was 21 % and 660 % higher than that of the cast composite. The improved strength and ductility of the high-volume Al composites (over 20 vol%) were attributed to the quasi-continuous architecture, which improved the plastic deformation ability of the ceramic-rich layers. For the composite extruded at 520 °C, the quasi-continuous architecture resulted in a back stress of up to 235 MPa higher than that of composites extruded at lower temperatures, accounting for 54 % of the flow stress. Additionally, the quasi-continuous architecture coordinated plastic deformation, mitigating the premature appearance of stress concentrations. This study provides a useful approach to enhancing the mechanical properties of nacre-inspired composites produced via ice templating, thereby broadening the range of applications for this technique.
研究领域:
材料科学
·
机械工程
·
复合材料
·
冶金学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2018
·
IF 4.92
Xiaomin Li,Juying Wu,Changyu Tang,Zhoukun He,Ping Yuan,Yong Sun,Woon-ming Lau,Kai Zhang,Jun Mei,Yuhong Huang
Boron carbide (B 4 C) is an important type of neutron radiation shielding material with relatively high efficiency due to the high content of 10 B element. Incorporation of B 4 C particles into polymer to prepare high-performance neutron radiation shielding material has become more and more important for the safe operation of nuclear power in the defense industry and nuclear power plant . The polyimide/B 4 C composite films with different micro-sized B 4 C contents were successfully prepared by in-situ polymerization. Silane coupling agent KH550 was employed to functionalize B 4 C particles to improve the dispersion of B 4 C particles in the polyimide matrix with strengthened interfacial interaction . As shown that the micro-sized B 4 C functional particles can be well dispersed in the BPDA/ODA polyimide matrix. With the B 4 C content increase, thermal stability of the polyimide/B 4 C composite films can be significantly improved, even mechanical properties partly declined. Meanwhile, the polyimide/B 4 C composite films exhibit good thermal neutron radiation shielding properties. The neutron permeability I/I 0 changes exponentially with the change of B 4 C content. When the B 4 C content is increased to 30 wt%, the polyimide/B 4 C composite films show optimum properties combination with thermal decomposition temperature (T d 10 ) of 622 °C, neutron permeability ( I/I 0 ) of 0.24 (800 μm in thickness), and tensile strength of 406 MPa. The composite thus shows great potential for use in applications which require materials with high thermal stability and neutron radiation shielding ability, such as fusion reactor system and nuclear waste disposal.
研究领域:
材料科学
·
核工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 14
·5153
·
IF 3.4
Qian Xia,Shihao Sun,Jun Ye,Cuiping Zhang,Hongqiang Ru
Reaction-bonded boron carbide (RBBC) composites have broad application prospects due to their low cost and net size sintering. The microstructure, reaction mechanism of boron carbide with molten silicon (Si), and mechanical properties have been substantially studied. However, the mechanical properties strengthening mechanism of reaction-bonded boron carbide composites are still pending question. In this study, dense boron carbide ceramics were fabricated by liquid Si infiltration of B4C-C preforms with dispersed carbon black (CB) as the carbon source. Polyethyleneimine (PEI) with a molecular weight of 1800 was used as the dispersant. CB powders uniformly distributed around boron carbide particles and efficiently protected them from reacting with molten Si. The uniformly distributed CB powders in situ reacted with molten Si and formed uniformly distributed SiC grains, thus forming a continuous boron carbide–SiC ceramic skeleton. Meanwhile, the Si content of the composites was reduced. Using PEI-dispersed CB powders as additional carbon source, the composites’ flexural strength, fracture toughness, and Vickers hardness reach up to 470 MPa, 4.6 MPa·m1/2, and 22 GPa, which were increased by 44%, 15%, and 10%, respectively. The mechanisms of mechanical properties strengthening were also discussed.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2017
·
IF 6.395
H.R. Jiang,W. Shyy,M.C. Wu,L. Wei,T.S. Zhao
The potential of B 4 C as a metal-free catalyst for vanadium redox reactions is investigated by first-principles calculations. Results show that the central carbon atom of B 4 C can act as a highly active reaction site for redox reactions , due primarily to the abundant unpaired electrons around it. The catalytic effect is then verified experimentally by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests, both of which demonstrate that B 4 C nanoparticles can enhance the kinetics for both V 2+ /V 3+ and VO 2+ /VO 2 + redox reactions, indicating a bi-functional effect. The B 4 C-nanoparticle-modified graphite felt electrodes are finally prepared and tested in vanadium redox flow batteries (VRFBs). It is shown that the batteries with the prepared electrodes exhibit energy efficiencies of 88.9% and 80.0% at the current densities of 80 and 160 mA cm −2 , which are 16.6% and 18.8% higher than those with the original graphite felt electrodes. With a further increase in current densities to 240 and 320 mA cm −2 , the batteries can still maintain energy efficiencies of 72.0% and 63.8%, respectively. All these results show that the B 4 C-nanoparticle-modified graphite felt electrode outperforms existing metal-free catalyst modified electrodes , and thus can be promising electrodes for VRFBs.
研究领域:
电化学
·
能源材料
·
催化化学
·
储能技术
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED RADIATION AND ISOTOPES
·
2021
·
IF 1.513
Oussama Mehelli,Mehdi Derradji,Raouf Belgacemi,Slimane Abdous,Abdelmalek Habes,Wenbin Liu
Aiming the development of advanced and lightweight thermal neutrons shields, a new hybrid composite was developed from UHMWPE fibers, epoxy and boron carbide (B 4 C) particles. The UHMWPE fibres were chosen because of their high hydrogen contents and exceptional mechanical properties. The neutrons shielding tests were performed using an optimized experimental setup at NUR research reactor, Algiers. Overall, the developed materials displayed remarkable neutrons screening performances. Meanwhile, the best performance was recorded at B 4 C amount of 20 wt% with a macroscopic cross-section (Σ) of with a 0.313 cm −1 equivalent to a mean free path (λ) of 2.2 cm.
研究领域:
材料科学
·
核工程
·
复合材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Macromolecular Science Part B-Physics
·
2024
·
IF 1.2
Wei Zhang,Guoqin Jiang,Yang Liu,Zongyi Deng,Zhixiong Huang,Xueyuan Yang
Carbon fiber/phenolic resin composites (CF/Ph) are often used on the surface of hypersonic vehicles as thermal protection materials. In this paper, the composite materials were prepared by a compression molding process with carbon fiber and boron phenolic resin modified by TiC and B4C. The high-temperature flexural strength and anti-ablation behavior of the composites (TB) were studied. The results showed that the residual weight yield at 1500 °C of TB-10 (B4C content of 10 phr) increased by 39.22% compared to that with no B4C (TB-0). The flexural strength of TB-10 was increased by 19.51% and 19.69% at 1400 °C and 1600 °C, respectively, with respect to TB-0 at the same temperatures. The linear ablation rate and mass ablation rate of TB-10 were reduced by 24.32% and 5.58%, respectively, compared with TB-0. By exploring the anti-ablative mechanisms, it was revealed that PyC, liquid B2O3 and TiO2, all of which were formed at high temperatures, tended to fill the inner cracks of the composite and, therefore, prevent the oxide to further diffuse in. Along with the outer ceramic layer, the three components above play a synergistic effect to improve the ablative property.
研究领域:
材料科学
·
航空工程
·
复合材料
·
高温技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Qian Kou,Chuntao Ge,Junjie Xu,Wenjuan Qi,Weiliang Jin,Ping Wang,Jun Zhang,Hongmin Zhu,Saijun Xiao
TiB 2 -coated cemented carbide cutting tools perform excellently in machining difficult-to-process metals such as titanium and aluminum alloys. We fabricated TiB 2 coatings on cemented carbides using molten salt electrophoretic deposition, consisting of in-situ synthesis of TiB 2 nanoparticles by borothermal reduction of TiO 2 in NaF-AlF 3 molten salts and subsequent electrophoretic deposition of the as-synthesized TiB 2 nanoparticles to form TiB 2 coatings in the same molten bath. This technique prepares a fully dense TiB 2 coating with a thickness of approximately 60 μm on a WC-8wt% Co substrate, exhibiting high hardness (36.7 GPa) and adhesion strength (48 N). Moreover, tribological property testing indicates that it possesses a lower coefficient of friction (0.55) and wear rate (8.69 × 10 −7 mm 3 /(N∙m)) compared with those of WC-8wt% Co substrate(coefficient of friction, 0.58; wear rate, 9.14 × 10 −7 mm 3 /(N∙m)).
研究领域:
材料科学
·
表面工程
·
电化学
·
制造工程
✓ 已验证
DOI
高影响因子
Journal of Macromolecular Science Part B-Physics
·
2023
·
IF 1.4
He Ding,Sige Huang,Xiaofan Liu,Zongyi Deng,Minxian Shi,Zhixiong Huang,Yue Wu
In order to investigate the effect of refractory metal on the high temperature properties of phenolic resin matrix composites, modified quartz fiber reinforced ceramizable composites were prepared by a molding process with a refractory component, tungsten, as the functional component and boron carbide as the ceramic forming agent. The effects of the tungsten and the boron carbide on the heat resistance of the composite were investigated. The results showed that the introduced refractory metal tungsten and the boron carbide can react to form tungsten borides and tungsten carbides at high temperature, and form a ceramic layer on the surface of the composite, which can fill the defects caused by pyrolysis of matrix and improve the high temperature performance of the composite. When the content of boron carbide was 10 wt% and the content of tungsten powder was 30 wt%, the flexural strength of the composite before and after heat treatment at 1200 °C were increased by 54.6% and 30.2% respectively compared with that without filler.
研究领域:
材料科学
·
复合材料
·
高温材料
·
陶瓷材料
·
聚合物基复合材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）