Journal of Asian Ceramic Societies
·
2023
·
IF 2.3
Yangshuo Bai,Weixia Shen,Chao Fang,Liangchao Chen,Qianqian Wang,Biao Wan,Xiaopeng Jia,Yuewen Zhang,Zhuangfei Zhang
Ultra-high-temperature ceramics are required for many aerospace applications. In this work, HfB2-30 vol.% HfC and HfB2-26 vol.% HfC-43 vol.% MoB high-density composites were prepared by one-step in-situ reactive spark plasma sintering (R-SPS) using Hf, B4C and Mo powders as starting materials. The influences of sintering temperature on the densification mechanism, microstructural evolution, mechanical properties and oxidation resistance of the composites were thoroughly investigated. The results demonstrate that the raw materials undergo a complete chemical reaction to form new binary HfB2-HfC and ternary HfB2-HfC-MoB composite structures at a temperature of 1300°C. The HfB2-HfC and HfB2-HfC-MoB composites prepared at the optimal conditions (pressure = 50 MPa, temperature = 1800°C, holding time = 5 min) had highre densities of 97% and 98%, respectively. The Vickers hardness, Young’s modulus and fracture toughness of the HfB2-HfC composite were 18.3 GPa, 525 GPa and 6.34 MPa·m1/2, respectively. However, after molybdenum was added, the Vickers hardness of the ternary HfB2-HfC-MoB composite increased to 19.4 GPa but its fracture toughness decreased slightly to 6.1 MPa·m1/2. Compared with the binary composite, the ternary composite exhibited a low and thermally stable oxidation rate up to a temperature of 1400°C, and the test was conducted in air atmosphere.
研究领域:
材料科学
·
航空航天工程
·
陶瓷
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2024
·
IF 4.1
Xingang Luan,Qinghua Zhao,Xuefei Sun,Shaomin Gu,Xichao Dong,Laifei Cheng,Ralf Riedel
Aiming at the lack of stable and reliable electrode materials for high temperature wireless sensors , a solution was proposed to use SiBCN ceramic as thin film electrode. To optimize the conductivity of SiBCN coatings, different conductive fillers were incorporated into the precursor solution to prepare conductive SiBCN coatings and the relationship between the coating process parameters, surface morphology and conductivity was established. The results show that the microstructure of the composite can be adjusted in terms of the HfB 2 /CNT ratio to optimize the electrical conductivity . HfB 2 and CNTs are evenly distributed in the coating by adding dispersants and ground SiBCN self-fillers. The electrical conductivity of SiBCN coatings can be greatly enhanced by adding HfB 2 and CNTs fillers. Integrating conductive fillers such as HfB 2 and CNTs can form a diafiltration path and the resistivity of the prepared coating has been determined to be as low as 0.13 ± 0.01 Ω m. The conductivity did not necessarily increase with an increasing amount of fillers. Adding a balanced amount of filler particles to the ceramic matrix is the requirement for optimizing the electrical conductivity of the coating.
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
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Bolin Yang,Changliu Kuang,Zhenglong Liu,Chao Yu,Chengji Deng,Jun Ding,Zhoufu Wang,Shixian Zhao
In order to effectively improve the density and oxidation resistance of ZrB 2 -SiC coating materials, HfB 2 was added into ZrB 2 -SiC system and their physical properties, oxidation resistance were explored. It was observed that the flexural strength of the spark plasma sintered sample with 8 vol% HfB 2 was 717.1 MPa, which was 162.6 % higher than that of the sample without HfB 2 (273.1 MPa). At the same time, the oxidation activation energy of the sample with 15 vol% HfB 2 was increased to 511.98 kJ/mol, showing excellent oxidation resistance. The oxidation process is that HfB 2 and ZrB 2 were oxidized prior to SiC to form HfO 2 and ZrO 2 to form a dense oxide layer on the outermost layer of the sample, and SiC reacted to form a second dense SiO 2 layer to hinder oxygen intrusion. In summary, diboride can achieve the synergistic effect of improving the oxidation resistance and structural optimization of ZrB 2 -SiC-HfB 2 coatings composites, which provides a theoretical basis for its practical application.
研究领域:
材料科学
·
高温材料
·
涂层技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2015
·
IF 2.947
Rong Tu,Nian Li,Qizhong Li,Song Zhang,Lianmeng Zhang,Takashi Goto
In order to improve the hardness and toughness simultaneously, B 4 C–HfB 2 –SiC ternary composites were synthesized by arc-melting using B 4 C, HfB 2 and β-SiC powders as raw materials. The ternary eutectic composition of 45B 4 C–15HfB 2 –40SiC (mol%) was first identified with a lamellar eutectic texture. HfB 2 about 500 nm in thickness and SiC about 700 nm in thickness were uniformly dispersed in B 4 C matrix of the eutectic composite, much smaller than raw powders. The Vickers hardness and fracture toughness of B 4 C–HfB 2 –SiC ternary eutectic were 35.7 GPa and 6.5 MPa m 1/2 at the eutectic composition, respectively.
研究领域:
材料科学
·
复合材料
·
陶瓷材料
·
高温材料
·
力学性能
✓ 已验证
DOI
高影响因子
CORROSION SCIENCE
·
2023
·
IF 8.3
Zhenyue Zou,Yan Qin,Kai Chang,Zhixiong Huang
Ceramicizable phenolic resin matrix composites are widely used in aerospace fields, and their heat resistance rating can reach 1400 °C. To further improve heat resistance, HfB 2 -SiB 6 ceramicizable phenolic resin matrix composites were prepared, and their thermal properties and oxidative corrosion behaviour were studied. The results showed that the composites with 30 % SiB 6 had a ceramic yield of 69.69 % at 1600 °C, and their linear and mass ablation rates were as low as 0.004 mm/s and 0.043 g/s, respectively. XRD and thermodynamic calculation showed that there were complex reactions to form Hf ceramics and Si-B-N-O to prevent corrosion under high temperatures of about 2000–2400 °C.
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 AMERICAN CERAMIC SOCIETY
·
2023
·
IF 3.9
Zhe Zhao,Cheng Han,Xiaozhou Wang,Yingde Wang
Metallopolymers containing refractory metal in the main chain are highly desired but rarely reported as oxygen-free single-source precursors for preparing ultrahigh-temperature ceramics. Herein, a novel single-source precursor of poly-hafnium-borocarbosilane (PHBCNS) with an Hf–N–B backbone molecular structure was synthesized through the dehalogenation reaction between HfCl 4 and B(NHCH 3 ) 3 . The polymeric Hf–N–B chain with large bond angle and conjugated molecular structure endowed the PHBCNS precursor to be relatively stable, dissolvable, and meltable. Subsequent precursor pyrolysis up to 1800°C resulted in an HfC/HfB 2 nanocomposite comprising an Hf content of 87.54 wt%, with the average grain size of HfC and HfB2 to be 34.9 and 74.1 nm, respectively. The ceramization mechanism and phase evolution from the PHBCNS precursor to HfC/HfB 2 composite ceramics were thoroughly investigated. This work not only highlights a novel Hf–N–B backbone polymer with high metal content and good shaping properties but also provides fresh insights of designing single-source precursors for ultrahigh-temperature composite ceramics.
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
COMPOSITE STRUCTURES
·
2024
·
IF 6.3
Fushuai Wang,Chi Zhang,Xinhui Geng,Qiang Gao,Liancai Xun,Wuju Wang,Xinghong Zhang,Ping Hu
With the increasing Mach numbers of hypersonic vehicles, extreme aerothermal environments impose substantial challenges on vehicle materials. High thermal conductivity materials facilitate rapid heat redistribution to diminish localized thermal accumulation and reduce material thermal damage, providing a viable route for further enhancing the operational temperature of materials. Here, we successfully fabricate high thermal conductivity C f /HfB 2 -SiC composites through the solid–liquid combination process, achieving an x-direction thermal conductivity of 161.11 W/(m·K), which represents an order of magnitude improvement over traditional carbon fiber-reinforced ultra-high temperature ceramic composites. 3D X-ray computed tomography (CT) is employed to analyze the structural composition of the high thermal conductivity C f /HfB 2 -SiC composites, and the Gaussian Mixture Model is applied to segment the CT images, thus establishing a mesoscale representative volume element (RVE) model based on CT. Combining theoretical models and finite element analysis, we propose a multiscale heat transfer model for high thermal conductivity C f /HfB 2 -SiC composites, which effectively investigates the heat transfer mechanisms of the composites. The fabrication and multiscale heat transfer modeling of high thermal conductivity C f /HfB 2 -SiC composites provide a theoretical basis and guidance for enhancing material performance and design optimization.
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Fan Zhang,Dewei Ni,Bowen Chen,Feiyan Cai,Hongda Wang,Le Gao,Ping He,Yusheng Ding,Shaoming Dong
Ultrahigh temperature and long-term ablation-resistant properties are critical and challenging for the utilization of materials as the thermal components of hypersonic vehicles. In this work, Y 2 O 3 reinforced C f /HfB 2 -SiC composites are designed and fabricated, which present superior ablation resistance with a mass recession rate of 2.10 mg/s and linear recession rate of 0.67 μm/s (with 3 wt% Y 2 O 3 addition) under long term ablation at a heat flux of 5.5 MW/m 2 (up to ∼ 2700 °C) for 300 s. The long-term ablation mechanisms of the composites are studied and revealed with the help of a detailed microstructure analysis and thermodynamic considerations. It is indicated that Y 2 O 3 reacts with both HfO 2 and SiO 2 , leading to the formation of a stable oxide layer with small HfO 2 -based grains skeleton dispersed in HfO 2 -Y 2 O 3 -SiO 2 glassy phase, subsequently improving the ablation-resistant performance of the composites. This work inspires new strategies for further optimization of ablation resistance of ultra-high temperature ceramic matrix composites.
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Hanwen Zhang,Zhen Wang,Kewei Li,Xian Dang,Mengen Hu,Yue Li,Shuxin Li,Ming Li,Zhulin Huang,Xiaoye Hu
Comprehensive performance of ultra-high temperature ceramic composites is predominantly governed by purity, morphology and crystallinity of HfB 2 powders. Nevertheless, achieving controllable synthesis of high-quality HfB 2 ceramic powders remains challenging due to insufficient mechanistic insights into the evolution and growth of powder morphology. In this work, we systematically investigate the effects of diverse carbon sources on the morphology and crystallinity of HfB 2 powders during carbothermal reduction. The results demonstrate that the graphitization degree of carbon sources directly governs whether HfB 2 powder exists in particle or rod-like morphology. Microstructural evolution analysis indicates that the morphological differentiation in HfB 2 powders is predominantly determined by the graphitization degree of the carbon source, which directly controls the oriented attachment of HfO 2 particles in precursors and modulates the reaction temperature during subsequent carbothermal reduction processes. The elevated graphitization degree promotes a more orderly arrangement of HfO 2 nanograins. The HfB 2 powders maintain the anisotropic rod-like morphology inherent in their HfO 2 precursors throughout the growth process, resulting in high-crystallinity, rod-shaped ceramic powders. These crystalline, rod-shaped powders display remarkable antioxidant properties; their mass fraction decreases by only 2.25 % following non-isothermal oxidation at 1000 °C. This research holds significant implications for developing controllable preparation methods for ceramic powders of different morphologies and provides a theoretical foundation for enhancing the performance of ultra-high temperature ceramic materials.
研究领域:
材料科学
·
陶瓷
·
纳米技术
·
热还原
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Yunlei Lv,Yongsheng Liu,Binghui Zhang,Xiaokun Sun,Yejie Cao,Yaming Wu
High-density HfB 2 -SiC ceramics were prepared by reactive melt infiltration (RMI) at a relatively low temperature (1500°C). The ceramics had the open porosity of 0.5 % and the uniform distribution of constituent phases. The long-term oxidation behavior of HfB 2 -SiC ceramics in air was investigated at 1650°C. After oxidation for 100 h, the weight gain rates of ceramics varied within the range of 1.30–2.26 %. The oxidation products included SiO 2 , HfO 2 , and HfSiO 4 phases, among which the HfSiO 4 compound possessed the higher stability resulting from the reaction between the HfO 2 and SiO 2 phases. The samples all exhibited the typical feature of layered scale structure after HfB 2 -SiC oxidation, which was composed of the outermost SiO 2 glass layer with the uneven thickness, followed by a relatively porous oxide layer containing white HfO 2 and slight HfSiO 4 , below it was the unoxidized HfB 2 -SiC. The presence of this multiphase glass layer endowed the samples with excellent oxidation resistance.
研究领域:
材料科学
·
高温材料研究
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2020
·Vol. 104
·期 2
·785-792
·
IF 3.502
Jinhua Zhang,Si Xiong,Jingran Wang,Yue’e Ni,Changming Ke
Phase pure and nano-sized hafnium diboride (HfB 2 ) fine powder was prepared via a novel sustainable silicothermic route at 1100°C from inexpensive raw materials HfO 2 , Na 2 B 4 O 7 and Si. By introducing sodium oxysalts as source of Na 2 O into the batch mixtures, the SiO 2 / Na 2 O modulus in the melt were reduced from 5:1 to 2:1, and the original water-insoluble byproduct SiO 2 was taken by the melt at test temperature and converted into water soluble sodium silicate (Na 2 Si 2 O 5 ) which was easily removed from the reacted mass via simple hot water washing. Consequently, the aqua sodium silicate could be readily recycled and used as a precursor for preparing many other valuable materials due to absence of foreign salts (eg halides, especially in the molten salt-assisted synthesis process) in the synthesis process, and the relevant environmental concerns could be alleviated. Using excessive amount of 20 wt% Si and 15 wt% Na 2 B 4 O 7 as compensation for the evaporation loss of silicon, in the form of SiO (g), and B 2 O 3 in the reduction process, a high reaction extent was achieved and HfO 2 and Na 2 B 4 O 7 were completely converted into HfB 2 at 1100°C.
研究领域:
材料科学
·
化学工程
·
可持续化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 24
·21305-21315
·
IF 2.195
Deng Qihuang,Wang Fupeng,Feng Yefeng,Xu Zhichao,Peng Cheng,Xu Xiaoqing,Li Wei,Wu Guoxun
The contradiction between high permittivity and breakdown strength in dielectrics is acknowledged. Although a sandwich structure endows the nanocomposites with ultrahigh breakdown strengths, the permittivity is limited ascribed to series connection of layers. In this work, a novel strategy from “meaty-sandwich” food was utilized to prepare the multi-layer polymer nanocomposites with finely balanced high permittivity and breakdown strength. HfB 2 nanorods, BaTiO 3 nanoparticles, and BN nanosheets were used as fillers. HfB 2 were surface-coated by polydopamine to gain the core–shell nanorods. High-content middle-layer composite results in a large dielectric response, while low-content bilateral-layer composite leads to high breakdown strength. Tri-layer composites with core–shell filler show high breakdown strengths. Five-layer composite with four high-insulation thin layers exhibits an ultrahigh breakdown strength and favorable permittivity. Breakdown mechanisms of composites were proposed. The best tri-layer composite shows a high permittivity of ~ 136@100 Hz and breakdown strength of ~ 263 MV m −1 . This work might pave a road for fabrication of promising dielectrics.
研究领域:
材料科学
·
电气工程
✓ 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）