COMPOSITES PART B-ENGINEERING
·
2024
·
IF 12.7
Yu Zhang,Xu Shen,Qin Ma,Shuang Mu,Shaoming Dong,Jinshan Yang
In this work, the mechanical behavior of NITE-SiC f /SiC composites, accompanied by the damage mechanisms of SiC fibers and BN interphase during NITE process, are investigated. The results show that the fracture characteristic of NITE-SiC f /SiC composite is transformed from quasi-ductile mode to brittle mode with the elevating temperature, as well as severe damage of SiC fiber and BN interphase. The damage of SiC fibers is originated from high temperature, sintering aids corrosion and matrix compression. High temperature and sintering aids diffusion lead to the grain growth and strength degradation of SiC fibers. The damage of BN interphase is caused by the sintering aids corrosion, mainly the reaction of Al 2 O 3 , and matrix compression. The stress distribution is simulated via finite element analysis proving that up to 17.5 GPa and 17.0 GPa stress originated from matrix shrinkage during sintering process is applied to the fiber and interphase respectively, making the fiber deformation and interphase fragmentation. The degraded fiber strength and destroyed interphase structure weaken the load-bearing capacity and crack deflection ability, causing degradation of mechanical properties and reliability of composites. This work helps to comprehensively understand and optimize the properties of SiC f /SiC composites prepared by NITE process.
研究领域:
材料科学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Jiang Wan,Gehui Wang,Weiyu Liang,Cheng Peng,Wei Zhang,Rongbing Fu
The unsatisfactory reuse performance of biochar in the catalytic system has become an important factor limiting its application. Damage of biochar in the catalytic systems has been reported, but the mechanism of damage is still unclear. In this study, cotton stalk and walnut shell biochar were used to activate peroxydisulfate (PDS) for sulfamethazine degradation, and multiple characterization methods were used to determine the damage of biochar. The comparative experiments of biochar, recycled biochar, and the biochar treated by PDS in catalytic reaction showed that the performance of biochars decreased by 37.5%–65.3%. After the catalytic reaction, the unstable carbon in biochar was lost, and the biochar surface was oxidized, which reduced its affinity to organic matter. CO 2 physisorption showed that the pore structure of biochars barely changed. However, for walnut shell biochar, its adsorption capacity of nitrogen decreased obviously. Moreover, the electrochemical tests showed that the conductivity of walnut shell biochar decreased, which would lead to the reduction of its catalytic performance through the electron transfer path. Overall, the effects of catalytic process on the performance of biochar cannot be ignored. Therefore, more efforts are needed to improve the stability and homogeneity of biochar as an efficient and sustainable PDS activator.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Ping Hu,Yuan Cheng,Maosong Xie,Yu Yang,Chang Liu,Qiang Qu,Xinghong Zhang,Shanyi Du
The damage mechanism of carbon fiber and fiber-ceramic interface of C f /ZrC-SiC were investigated and revealed. The chemical reactions of C with ZrO 2 and SiO 2 impurities during the sintering resulted in the surface and grain etching of fiber. The ZrC-SiC ceramics diffused into interface to form a strong bonding under high temperature and press, leading to a failure of stress release and guiding the crack propagation direct across fiber. Both consequently impeded the fiber pull-out and bridging. By obvious contrast, the chemical etching of fiber was effectively inhibited utilizing PyC coating as transition layer, and the strong bonding of fiber with ceramic was relieved at the same time replaced by a relatively weak bonding. As a result, the fiber pull-out and fiber bridging were boosted with a longer length more than 50 µm, over 2 times of uncoated composite, accompanied with obvious crack branching and deflection, together resulting in a graceful mechanical feedback with 2.5 times of work of fracture and improved fracture toughness . This work not only revealed the microstructure forms and inherent mechanism on structure damage of carbon fiber, but also offered an effective method of protecting fiber and tailoring the interface bonding, thereby guiding the design of C f /ZrC-SiC with graceful mechanical performance.
研究领域:
材料科学
·
复合材料
·
界面工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Wenhao Dou,Bingzhu Wang,Daxin Li,Haobo Jiang,Xiaoliang Sun,Ling Li,Yingying Wang,Zhihua Yang,Dechang Jia,Yu Zhou
To enhance the ablation resistance of porous C sf /MA–SiBCN composites, the polymer infiltration and pyrolysis (PIP) process is adopted to obtain layered C sf /SiBCN composites containing MA–SiBCN and PDCs–SiBCN. After ablation for 10 s, the ablative layer fails to remain on the C sf /MA–SiBCN surface with mass ablation rate of 0.062 g/s and linear ablation rate of 0.208 mm/s, while the dense C sf /SiBCN surface is covered by a dense and stable ablative layer mainly consisting of amorphous SiO 2 glassy phase due to the synergistic ablation effect of MA–SiBCN and PDCs–SiBCN, which could resist the intense scour by ablation flame and prevent internal corrosion, and thus the ablation resistance improves with a 37% decrease in mass ablation rate (0.039 g/s) and an 18% decrease in linear ablation rate (0.171 mm/s), respectively.
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
International Journal of Applied Ceramic Technology
·
2023
·Vol. 20
·期 3
·1646-1657
·
IF 2.1
Lu Fu,Shifeng Wen,Wanbo Hou,Xinhao Shi,Tao Feng,Mingde Tong
2D-C/HfC–SiC composites were prepared by a combination of precursor infiltration and pyrolysis (PIP) and chemical vapor infiltration (CVI). Creep tests were performed at 1100°C in air under different stress conditions. Unlike most, C/SiC and SiC/SiC ceramic matrix composites only underwent primary and secondary creep stages, and the C/HfC–SiC composites underwent tertiary creep stage in the creep process. The reason was that the mechanical properties of C/HfC–SiC materials prepared by PIP + CVI methods were different from those prepared by traditional methods. The microscopic morphological analysis of the sample fracture showed that the oxidation products SiO 2 and Hf–Si–O glass phases of the HfC–SiC matrix played a crack filling role in the sample during creep. In turn, it provided effective protection to the internal fibers of the sample. The creep failure of C/HfC–SiC composites in a high-temperature oxidizing atmosphere was caused by the oxidation of the fibers. The total creep process was dominated by the oxidation of carbon fibers. It is noteworthy that there was the generation of Hf x Si y O z nanowires in the samples after high-temperature creep. The analysis of the experimental data showed that the creep stress had a linear negative correlation with the creep life.
研究领域:
材料科学
·
力学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Xinlei Zhang,Bin-Bin Zhang,Xiao Ma,Maosen Fu,Gangqiang Zha,Wanqi Jie
Irradiation damage in halide perovskites usually enhances ion migration, decomposition, formation of intermediate phases, etc., which further decrease the working stability of halide perovskite optoelectronic devices. For example, due to the beam-sensitive nature of halide perovskites, the artifact information about local structures and microstructures is difficult to avoid during transmission electron microscopy (TEM) characterization. The interaction mechanism between high-energy electron beams and halide perovskites is still unclear. In this work, the electron-beam irradiation effect on solution-grown halide double perovskite Cs2AgBiBr6 crystals was systematically investigated by TEM. Depending on the different orientations of Cs2AgBiBr6, two kinds of electron beam irradiation damage were observed. When the irradiation on Cs2AgBiBr6 is along the [110]pc zone axis, a new phase Cs2Ag0.5BiBr6 with a vacancy-ordered superstructure forms, which is attributed to the “knock-on displacement” mechanism. In contrast, when the electron beams are along the [111]pc zone axis of Cs2AgBiBr6, an amorphous phase is gradually generated due to the “radiolysis” mechanism. Our finding clearly reveals the characteristics of irradiation damage in representative halide perovskites and further provides a new understanding of the working instability of halide perovskite optoelectronic devices.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
International Journal of Applied Mechanics
·
2024
·
IF 2.9
Kunquan Wang,Lu Dai,Ji Lin,Ping Rao,Rui Xiao
We combine experimental analysis and modeling to investigate the complex mechanical behaviors of copolymer elastomers. Experimental studies are conducted to analyze the impact of monomer ratio, strain rate, and loading mode on the response of copolymer elastomers, which reveal the distinct hyperelastic, viscoelastic, damage and self-recovery behaviors of the materials. Based on the experimental observations, we develop a finite deformation hyperelastic-viscoelastic constitutive model, which incorporates multiple discrete relaxation processes. For the hyperelastic process, an extended eight-chain model is employed. Different from the classic viscoelastic model, the strain hardening and damage/recovery mechanisms are also included in the relaxation processes. The model successfully describes the complex mechanical responses observed in elastomers, including quasi-static loading, strain rate effects, and stress relaxation phenomena. Additionally, the model captures the behavior of elastomers during loading-unloading cycles in a reasonable manner. The work offers an efficient theoretical tool for the design and practical application of elastomers.
研究领域:
材料科学
·
固体力学
·
高分子科学
·
本构关系
·
实验力学
✓ 已验证
DOI
高影响因子
ERGONOMICS
·
2023
·
IF 2.4
Veeresalingam Guruguntla,Mohit Lal
Biomechanical models are mathematical representations of human structure. These models are used to analyse joint and injury mechanics and design of prosthetic devices for human body under various conditions. Biomechanical model development involves the integration of knowledge from various fields, including mechanics, biology, physiology, and mathematics. Biomechanical models have become more significant in the healthcare sector as researchers strive to offer better medical supplies and ride comfort. It has uses in automobile and sports science as well, to create human dummies for accident and segmental vibration transmissibility study, improve training routines, and prevent injuries. These biomechanical models might be anything from straightforward lumped parameter models to intricate multi-body models. The virtues, weaknesses, and contemporary uses of lumped parameter modelling and multi body modelling in biomechanical modelling are discussed in this article. Subsequently, emphasised the recent modelling improvements and explored the future direction of biomechanical modelling. Researchers and professionals who wish to apply biomechanical models to comprehend human movement and enhance performance may find this review to be helpful.
研究领域:
生物力学
·
生物医学工程
·
运动医学
·
康复工程
·
人体工效学
·
创伤力学
·
计算生物学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）