JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Junjie Xu,Wei Sun,Xiang Xiong,Hongbo Zhang,Lingkun Yang
To improve the mechanical properties and ablation resistance of Cf-reinforced ceramic-based materials, ZrC–W cermet composites (C/C–ZrC–W) were prepared in C/C preforms using slurries and low-temperature reactive melt infiltration , and their microstructure, formation mechanism, and mechanical and ablation properties were investigated. The obtained results revealed that the formation of C/C–ZrC–W composites involved the dissolution–precipitation and C diffusion processes. Owing to the precipitation of W nanoparticles in the ZrC phase and interdiffusion of W/ZrC, the fabricated C/C–ZrC–W composites exhibited superior mechanical properties with a flexural strength of 280.65 ± 12.84 MPa and fracture toughness of 13.87 ± 0.56 Mpa.m 1/2 . The formation of a Zr–W–O dense oxide layer resulted in the excellent ablation performance of the C/C–ZrC–W composites in oxyacetylene flame with a temperature of 2200 °C, and their mass ablation rate and linear ablation rate were 1.14 mg/s and 2.42 µm/s, respectively. The described method can be potentially used for preparing high-strength, high-toughness, and ablation-resistant materials at low temperatures.
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DOI
高影响因子
MATERIALS & DESIGN
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2024
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IF 7.6
Nana Zhu,Lu Zhu,Baojing Zhang,Peizhong Feng,Shiheng Li,Philipp V. Kiryukhantsev-Korneev,Evgeny A. Levashov,Xuanru Ren,Xiaohong Wang
An innovative two-step approach of self-propagating high-temperature synthesis (SHS) and spark plasma sintering (SPS) was developed to rapidly fabricate MoSi 2 and Mo(Al,Si) 2 ceramics for high-temperature anti-oxidation applications. The SHS process predominantly promoted the synthesis of high-purity and high-yield MoSi 2 and Mo(Si,Al) 2 phases in the alloyed powders. Subsequently, dense and crack-free MoSi 2 and Mo(Al,Si) 2 ceramics were produced using SPS. 1500 °C oxidation tests of the ceramics (100 h) revealed the formation of a protective SiO 2 oxide layer on the surface of MoSi 2 ceramics, while an Al-Si-O composite glassy oxide layer formed on Mo(Si,Al) 2 ceramics, which exhibited better thermal stability and lower oxygen permeability compared to the single SiO 2 oxide layer. However, an excessive Al content (>0.05 at.%) compromised the oxidation resistance due to the emergence of a Si-depleted Mo 5 (Si,Al) 3 layer with inferior oxidation resistance, which was caused by the high-temperature diffusion of Si. Therefore, via this novel two-step SHS-SPS technique compact and crack-free Mo(Si,Al) 2 ceramics can be rapidly synthesized at high temperatures. When trace amount of Al was added (0.05 at.%), Mo(Si 0.95 Al 0.05 ) 2 showed optimum high-temperature oxidation resistance.
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2019
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IF 4.029
Lu Zilong,Yue Jianling,Fu Zeyu,Huang Xiaozhong,Yang Haitang
SiC f /BN/SiC mini-composites comprising single tow SiC fibre-reinforced SiC with chemical vapour deposited (CVD) BN interface layers were fabricated. The mechanical performance and binding strength of the composites and the fibre/interface for the oxidized SiC f /BN/SiC mini-composite samples (oxidation at 1000, 1200, 1300, 1400 and 1500 °C in air for two hours) were investigated by tensile tests and fibre push-out tests, respectively. The value of oxidation mass change was also measured. Some unusual phenomena for the SiC f /BN/SiC mini-composites oxidized at 1000 °C were discovered in this work. The tensile strength reached a maximum value, and the mass gain rate showed as a singular negative value, while the shear strength between the fibre and the matrix was moderate. Scanning electron microscopy, energy dispersive spectrometry, infrared spectroscopy and X-ray diffraction characterization methods were used to reveal the microstructural evolution and investigate the unusual phenomenon during oxidation procedures. This work will provide guidance for predicting the service life of SiC f /BN/SiC composite materials and may enable these materials to become a backbone for thermal structure systems in aerospace applications .
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2024
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IF 5.1
Ruiji Zhang,Fangwei Guo,Wenchen Zhang,Fei Pan,Xing Zhang
Ceramics containing profiled fiber-like additives (nanotubes, whiskers, etc.) show high mechanical properties. However, the toughening mechanism is debated due to its complex multi-scale microstructure. In this work, ZrB 2 (Z)-20 vol%SiC(S) spiral fibers (ZS sf ) were prepared by liquid rope effect and non-solvent induced phase separation, while quantitative relation of mechanical properties and structure were investigated by using SEVNB with femtosecond lasers and in-situ 3D-XRM simulation. The ZrB 2 -SiC composites with hierarchy ZS sf exhibited a ∼60 % increase in fracture toughness (5.45 MPa m 1/2 ) compared with blank composites, while the toughening efficiency of the hierarchy ZS sf increased over 2 times compared to the 1D and 2D toughening additives. The ZS sf with a thin graphite-like layer and spiral structure with hierarchy pores provided a torsional release effect that changed brittle fracture to the pseudoplastic fracture, where topological interlocking of 3D crimped structure hindered rapid cracking propagation. Additionally, the enhanced toughness was attributed to the uniform reconstruction of the stress field induced by hierarchical inner pores. The preserved 3D topological interlocking and uniform stress reconstruction lead to the highly stable fracture toughness of the ZS sf composites up to 1500 °C.
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DOI
高影响因子
危险品化学品经营许可证（带存储）