JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Fuping Li,Zhuoli Xu,Kang Zhao,Yufei Tang
ZrB 2 -ZrC composite nanofibers were fabricated by electrospinning and carbothermal reduction. The morphology, phase composition and interface were characterized. The fabricated ZrB 2 -ZrC composite nanofibers are uniform and the diameter is about 100 nm. The effects of heat-treatment temperature, n(B)/n(Zr) and n(C)/n(Zr) on the microstructure and phase composition of composite nanofibers were systematically investigated. The results shows heat-treatment temperature has influence on the phase composition and grain size of the ZrB 2 -ZrC composite nanofibers. The content of ZrC in the ZrB 2 -ZrC composite nanofibers can be adjusted by the value of n(B)/n(Zr) in the precursors. As n(B)/n(Zr) equal to 3.5, the mass ratio between ZrB 2 and ZrC is about 48:52 which is very close to the eutectic composition of ZrB 2 -ZrC composites. The value of n(C)/n(Zr) also affects the phase composition of composite nanofibers. Reaction process and phase evolution during heat-treatment were studied based on analysis of reaction thermodynamics. The value of n(B)/n(Zr) influences the phase evolution during fabrication of ZrB 2 -ZrC composite nanofibers. The tensile mechanical properties were tested, indicating that the addition of ZrC has the ability to improve the plasticity of ZrB 2 .
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2019
·
IF 2.338
Li-ping RAN,Fei RAO,Ke PENG,Huan YIN,Mao-zhong YI
Ultrahigh-temperature ceramics were added to C/C composites to meet their application requirement in a high-temperature oxidizing environment. C/C−ZrB 2 −SiC composites were fabricated by high-solid-loading slurry impregnation with polymer infiltration and pyrolysis. The dispersion and rheological behavior of ZrB 2 slurry and the microstructural, mechanical, and ablation properties of the C/C−ZrB 2 −SiC composites were investigated. Results indicated that a well-dispersed and low-viscosity ZrB 2 slurry was obtained using 0.40 wt.% polyethyleneimine as a dispersant at pH 5. Ceramics were uniformly distributed in the short-cut fiber layer and needle-punched area. The flexural strength of the C/C−ZrB 2 −SiC composites was 309.30 MPa. The composites exhibited satisfactory ablation resistance under the oxyacetylene flame of 2500 °C, and the mass and linear ablation rates were 0.40 mg/s and 0.91 μm/s, respectively. A continuous and compact ZrO 2 layer, which could effectively reduce the diffusion rate of oxygen and protect the composites from being ablated, was formed.
研究领域:
材料科学
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航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
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2016
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IF 2.263
J.J. Sha,J. Li,S.H. Wang,Z.F. Zhang,Y.F. Zu,S. Flauder,W. Krenkel
Ultra-high temperature ceramics are potential materials for a variety of high temperature applications because of excellent thermo-mechanical properties and oxidation resistance . To further improve their fracture properties, a novel colloidal process was proposed to fabricate the short carbon fiber-toughened ZrB 2 –ZrSi 2 composites. Microstructure analysis found that the colloidal processing route could avoid the fibers' agglomeration and alleviate the fibers' damage, which minimizes the structural defects and retains the fibers' strength . The relative density of composites achieves 98.35% and the distribution of fibers in matrix is homogeneous. Mechanical tests indicate that the flexural strength is 458 MPa and the fracture toughness is 6.9 MPa·m 1/2 . In comparison to the composite obtained by conventional processing route, the fracture toughness increases by 47%. The main mechanisms for improved fracture properties could be attributed to the crack deflection, fiber sliding and fiber bridging.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Mingcheng Zhu,Lan Zhang,Na Li,Desen Cheng,Jidong Zhang,Shiyao Yu,Hui Bai,Huizhong Ma
Ternary ZrB 2 –SiC–MoSi 2 composites with different nominal volume fractions of SiC (10–25 vol%) and MoSi 2 (5–20 vol%) were sintered by reactive spark plasma sintering (RSPS) at 1650 °C and 35 MPa from the starting powders of ZrB 2 , Si, Mo and activated charcoal. The densification behaviour, microstructures and mechanical properties were comprehensively investigated. SiC clusters and MoSi 2 were formed by in-situ reactions and the improved sintering efficiency was attributed to the mass transfer by liquid Si. The formation of a core–shell (Zr, Mo)B 2 solid solution was confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). With the addition of the nominal MoSi 2 content up to 15 vol%, the molar ratio of MoB 2 in the solid solution shell increased owing to the increase of Mo; the densification and mechanical properties decreased owing to the softness of MoSi 2 , the cracks, and the large size of SiC clusters. The relative density, Vickers hardness , and fracture toughness of ZrB 2 –SiC–MoSi 2 composites were significantly better than those of bulk ZrB 2 owing to the combined effect of phase enhancement and solid solution strengthening.
研究领域:
材料科学
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机械工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Ceramic Engineering and Science
·
2020
·Vol. 2
·期 2
·101-109
·
IF 0
Anzhe Wang,Hailong Liao,Tao Zhang,Minqi Jiang,Fuxiao Guo,Yongzheng Wang
Reliable evaluation of the thermal shock behavior of sharp leading edges (SLEs) was hampered by a lack of available experimental method in past decades. Herein, a novel water spraying method was utilized to investigate the shape effect of ZrB 2 -SiC-Graphite SLEs during thermal shock. Experimental results indicated that the critical failure temperature of ZrB 2 -SiC-Graphite SLEs was most sensitive to the wedge angle, which could lead to a dramatic attenuation by about 35% from 12° to 9°, and was relatively little affected by the tip radius of curvature and the thickness. Simulation results further revealed that the decay of critical failure temperature was mainly due to the significant stress concentration caused by the reduction of wedge angle. Scanning electron microscopy observation proved that cracks tend to bypass graphite flakes due to their weak interfacial bonding, while branching always occurred when encountering hard phases or inclusions.
研究领域:
材料科学
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热力学
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结构力学
✓ 已验证
DOI
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Dongyang Zhang,Hongying Yu,Anzhe Wang,Qi Wang,Lu Ren,Ping Hu,Dongbai Sun
The need for synergy of strengthening and anti-oxidation under high-temperature and oxidative environment imposes new demands on nonablative thermal protection materials. Herein, 2D C f /ZrB 2 -SiC composite with superior damage tolerance and excellent oxidation resistance were constructed using a simple fiber heat treatment. An enhanced flexural strength of 234 ± 18 MPa and an intermediate work of fracture of 1342 J/m 2 were obtained for 2D C f-HT /ZrB 2 -SiC composite, increasing by nearly 19.4% and 171.7% as compared with those of C f-AR /ZrB 2 -SiC sample, triggered by multiple toughening mechanisms including crack bifurcation, fiber bundles pull-out and bridging. The surface of 2D C f-HT /ZrB 2 -SiC composite was covered with a dense silica glass layer and embedded with a few zirconia particles after oxidation at 1500 °C for 1 h, resulting in an excellent oxidation resistance. This work presents a simple approach to achieve the synergy of superior damage tolerance and oxidation resistance of continuous carbon fiber reinforced ceramic matrix composite.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2020
·
IF 4.495
Yingjun Liu,Yufei Zu,Hongliang Tian,Jixiang Dai,Jianjun Sha
A process combining electrophoretic deposition (EPD) with hot pressing (HP) was developed to fabricate continuous carbon fiber-reinforced ZrB 2 -based composites (C f /ZrB 2 -based composites). ZrB 2 -based ultra-high temperature ceramic (UHTC) particles were uniformly pre-coated on continuous carbon fibers via EPD. Then, the UHTC-coated carbon fibers were stacked and hot pressed to prepare the C f /ZrB 2 -based composites. Microstructure observations revealed that almost no micro-pores were found in the inter-bundle and intra-bundle regions of fibers after HP. The flexural strength , fracture toughness and the work of fracture of the C f /ZrB 2 -based composite were measured as 199 ± 26 MPa, 6.71 ± 1.29 MPa·m 1/2 , and 754 ± 58 J/m 2 , respectively. Based on the observations of non-brittle fracture behavior , fractured morphology and crack propagation , the enhanced fracture properties were mainly attributed to the multiple toughening mechanisms, such as fiber pull-out, fiber bridging, crack deflection and branching along the interfaces.
研究领域:
材料科学
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复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Xiangzhao Zhang,Puhao Xu,Xinyue Wu,Xinyi Gui,Guiwu Liu,Mingfen Zhang,Haining Meng,Guanjun Qiao
The wetting of ZrB 2 ceramic by molten pure Cu, Cu-(20, 30, 40, 50 at.%)Ti alloys were performed by the sessile drop method under vacuum of ∼4 × 10 −4 Pa in the 1030−1070 °C temperature range. The wetting and interfacial behaviors of Cu-Ti/ZrB 2 systems were analyzed and discussed. Furthermore, the work of adhesion and electronic properties of the Cu(1 1 1)/ZrB 2 (0 0 0 1) and Ti(0 0 0 1)/ZrB 2 (0 0 0 1) atomic interfaces were quantitatively evaluated by first-principles method. The wettability is significantly improved with the Ti concentration or wetting temperature increasing as a result of the formation of (Ti) solid solution at interface. The calculated results show that the B-terminated ZrB 2 (0 0 0 1) surface is preferable to bond with Ti(0 0 0 1) surface, and the electronic structure reveals that the dominant interfacial bonding is the Ti-B ionic bond for the Ti/B-terminated ZrB 2 interface.
研究领域:
材料科学
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表面科学
·
计算材料学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Yehong Cheng,Yang Lyu,Shanbao Zhou,Wenbo Han
Although axially aligned fibrous monolithic ceramics have superior mechanical properties in ceramic fiber axial direction, the obvious anisotropy in physical and chemical properties of fibrous monolithic ceramics predetermine the significant on-axis and off-axis discrepancy. The existing ZrB 2 -based fibrous monolithic ceramics were all arranged by axially aligned ceramic fibers. Non-axially aligned ZrB 2 -SiC/ZrB 2 -SiC-graphene short fibrous monolithic ceramics with isotropic in-plane properties were fabricated by hot pressing of disorderly-arranged short ZrB 2 -SiC/ZrB 2 -SiC-graphene fibers to overcome in-plane anisotropy of the ZrB 2 -based fibrous monolithic ceramics. ZrB 2 -SiC/ZrB 2 -SiC-graphene short fibrous monolithic ceramics have remarkable increase in fracture toughness, critical crack size and work of fracture compared with ZrB 2 -SiC ceramics. The toughening mechanism of ZrB 2 -SiC/ZrB 2 -SiC-graphene short fibrous monolithic ceramics include macroscopic toughening of crack deflection, crack branching, interface friction and ZrB 2 -SiC cell extraction, and microscopic toughening of graphene bridging and pull-out.
研究领域:
材料科学
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陶瓷
·
复合材料
·
力学性能
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Yingjun Liu,Jin Wang,Ran Jing,Yang Zhang,Zhongni Liao,Yufei Zu
Continuous carbon fiber-toughened ZrB 2 -based composites (C f /ZrB 2 -based composites) are potential thermo-structural materials suitable for ultra-high temperature applications. To improve the fracture properties, polydopamine-derived carbon (PDC) was deposited on carbon fibers and used as a boundary layer of C f /ZrB 2 -based composite (C f /PDC/ZrB 2 ). Results indicated that PDC was applied uniformly to fibers, with no instances of cross-sticking observed among adjacent fibers. The matrix could effectively infiltrate into the intra-bundle region, resulting in the formation of a highly dense C f /PDC/ZrB 2 composite. PDC can effectively modulate the interface of C f /ZrB 2 -based composite. Using polydopamine-derived carbon (PDC) as a boundary layer, the average interfacial shear strength of the composite was decreased from 369 MPa to 133 MPa. The fracture toughness of C f /PDC/ZrB 2 composite was 8.4 MPa·m 1/2 , representing a 19 % enhancement in comparison with the composite without a PDC layer. The work of fracture of C f /PDC/ZrB 2 composite was 8.5 kJ·m −2 , significantly surpassing that of the composite without a PDC layer (1.7 kJ·m −2 ). The outstanding fracture properties can be attributed to the beneficial interfacial bonding established by PDC layer between fiber and matrix, which promotes the activation of toughening mechanisms including crack branching/deflection and fiber bridging/pull-out.
研究领域:
材料科学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Zanchao Gao,Yumin An,Kailei Xu,Yehong Cheng,Libin Zhao
This study presents a novel fabrication strategy for unidirectional carbon fiber/ceramic films and integrates them with helical assembly, compression molding, and precursor infiltration and pyrolysis to construct a biomimetic Bouligand structure in ZrB 2 -SiC based composites. With a fixed helix angle of 30°, the influence of carbon fiber volume fractions (20 %, 30 %, 40 %) on the mechanical properties was investigated. The C f /ZrB 2 -SiC composites with 40 vol% carbon fiber exhibited the highest mechanical properties. Building upon this result, the effect of different helix angles (15°, 30°, 45°, 60°) on the mechanical properties was further investigated. The C f /ZrB 2 -SiC composite with 40 vol% fiber and a 60° helix angle sample exhibited the best overall mechanical performance, characterized by a flexural strength of 346.9 MPa, fracture toughness of 11.8 MPa·m 1/2 , and work of fracture of 5170.6 J·m −2 . SEM and CT analysis revealed that toughening was primarily attributed to crack deflection, microcracking, fiber pull-out, and bridging mechanisms.
研究领域:
材料科学
·
复合材料
·
机械工程
·
仿生学
·
陶瓷材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Jun Lu,Dewei Ni,Bowen Chen,Feiyan Cai,Zou Xuegang,Xiangyu Zhang,Yusheng Ding,Shaoming Dong
Pitch-based short carbon fibres reinforced C sf /ZrB 2 -SiC composites were fabricated by direct ink writing of short carbon fibres, followed by slurry impregnation and reactive melt infiltration . Ablation behaviour of the C sf /ZrB 2 -SiC composite was studied by air plasma test. It is indicated that the skeleton of the oriented short carbon fibres provides heat diffusion channels. Consequently, temperatures at the ablation surface are as low as ∼1730 o C and ∼2000 o C respectively at 4 MW/m 2 and 5 MW/m 2 . The composite presents outstanding ablation-resistant performance with a linear recession rate of ∼ − 0.04 µm/s and mass recession rate of ∼ − 3.40 mg/s at 4 MW/m 2 , ∼ − 0.17 µm/s and ∼ 3.58 mg/s at 5 MW/m 2 . It is revealed that the fibres area and matrix area of the composite present different ablation mechanisms. The fibres area is ablated severely, while the matrix area presents excellent ablation-resistance with continuous ZrO 2 -SiO 2 protective layer.
研究领域:
材料科学
·
航空航天工程
✓ 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）