JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Biao He,Zhiwei Han,Jingyan Wang,Yaning Li,Jian Li,Saichao Song,Chen Li,Wei Liu,Chengyang Wu
Fluorine-based aluminum thermite have excellent ignition and combustion properties. Nonetheless, its combustion kinetics and energy release are hindered by slow mass diffusion and incomplete reactions. Therefore, this study successfully prepared an Al@PTFE composite with a core-shell structure, utilizing mechanical activation and sintering techniques, to enhance combustion properties and energy release rate. SEM, XRD, FTIR and XPS characterization results demonstrate the unique core-shell structure of the samples and the homogeneous distribution of elements on the surface. In comparison to the physical mixture, the Al@PTFE composite exhibits significantly higher values for P max (2.19 times), P max /Δt (11.30 times), and flame propagation velocity (4.5 times). Furthermore, the combustion duration required to reach the maximum flame height was reduced by 131.75 ms. The adsorption, decomposition and reaction processes of PTFE on the surface of aluminum particles were demonstrated based on RMD simulations. The promotion mechanism of PTFE on combustion in aluminum particles was elucidated.
研究领域:
材料科学
·
燃烧化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 5
·4115-4123
·
IF 2.993
Zhou Xiang,Zhu Ying,Ke Xiang,Zhang Kaili
In this study, we use simultaneous differential scanning calorimetry and thermogravimetric analysis to analyze the solid-state reaction characteristics of Al/Fe 2 O 3 nanothermites before n -Al melts. Different experimental setups for thermal analysis are compared, and the heat-release characteristics are studied on Al/Fe 2 O 3 nanothermites in the form of powder and pellet, respectively. It is found that protection provided by mere argon flow is far from enough for thermal analysis of Al/Fe 2 O 3 nanothermites. The experimental setup must be free of oxygen; otherwise, the determined exothermic peak is mostly the oxidation of n -Al by the residue oxygen molecules in the furnace body, due to the high reactivity and moderate accessibility of free oxygen molecules. Under proper experimental setup, it is found that besides the redox reaction between n -Al and n -Fe 2 O 3 , intermetallic reaction also occurs to form Fe 4 Al 13 . Moreover, the intermetallic reaction is more noticeable for nanothermite pellet than for nanothermite powder, and the eutectic reaction of Fe 4 Al 13 and n -Al leads to melting peaks below 655 °C. The results indicate that instrument configuration and sample status affect the testing results to a large extent, and one should be prudent to derive reaction characteristics of nanothermites.
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 ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Haifeng Yang,Chuanhao Xu,Shuaishuai Man,Hebin Bao,Yuting Xie,Xiaodong Li,Guangcheng Yang,Zhiqiang Qiao,Xueming Li
Effects of hollow carbon nanospheres on the combustion behavior of Al/Fe 2 O 3 -based thermite sticks are studied in this work. The results from laser ignition experiments confirm that the presence of hollow carbon nanospheres not only can reduce the ignition threshold because of the excellent laser energy absorption capacity, but also play a positive role in heightening the heat transfer efficiency by introducing pores and increasing heat-flow output during the combustion process. The video snapshots indicate that the combustion propagation stages, including ignition, acceleration, and steady combustion, all improved significantly with the suitable inclusion of hollow carbon nanospheres. The modified composites containing 4 wt% hollow carbon nanospheres exhibit a minimum ignition threshold (28 mJ), shorter acceleration duration (76 ms), higher combustion rate (10.10 cm/s) and steady combustion temperature (~2850 K). Furthermore, it exhibits a remarkable enhancement in energy release (537.36 J/g) and pressure output (0.91 Mpa), which are 1.67 and 1.34 times than that of pristine thermite sticks, respectively. Overall, this work demonstrates that the high porosity structure and heat-flow release of thermite sticks facilitate convective heat transfer and eventually improve the combustion behavior, which can provide some reference in the design and optimization of microstructure and composition in micro-energetic devices.
研究领域:
材料科学
·
燃烧与爆炸
✓ 已验证
DOI
高影响因子
COMBUSTION SCIENCE AND TECHNOLOGY
·
2025
·
IF 1.5
Baichen Chen,Yi Wang,Jianchen He,Xiaolan Song,Chongwei An
This article uses a combination of experimental and simulation methods for mutual verification to explore the possibility of nano aluminum thermite damaging chips and disrupting circuit systems. In terms of experiments, Fe2O3/SiO2/Al and SnO2/SiO2/Al aluminum thermites were prepared by physically mixing micro Al powder, nano SiO2, and nano metal oxide powder in a certain proportion. The binder was added and pressed into a charge column for ignition testing. The prepared aluminum thermite was characterized and its performance was tested using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy(XPS), and constant pressure combustion experiments.In terms of molecular dynamics simulation, Materials Studio software was used to investigate the interaction relationships between atoms in the aluminum thermite. The reaction process and properties of the aluminum thermite under adiabatic conditions at different initial temperatures were explored from the perspectives of potential energy, radial distribution function, mean square displacement, and self diffusion coefficient. The simulation results were compared with experimental reaction phenomena. The results show that the aluminum thermite prepared by physical method is uniformly mixed, various materials are fully adhered, well dispersed, and there is no agglomeration phenomenon. In terms of combustion performance, the overall performance of Fe2O3/SiO2/Al thermite is better than that of SnO2/SiO2/Al thermite, with higher combustion efficiency, higher reaction temperature, and the ability to maintain high temperature for a longer period of time. The combustion of Fe2O3/SiO2/Al aluminum thermite is more complete, and the reaction generates more elemental Si, which plays a positive role in the damage of chips. In terms of molecular dynamics simulation, the aluminum thermal reaction of Fe2O3/SiO2/Al at different initial temperatures is more stable, with a faster energy release rate and a higher total energy content than SnO2/SiO2/Al. The aluminum thermal reaction generates oxides of elemental Fe/Sn, Si, and Al. Overall, the diffusion coefficients of both aluminum thermites increase with the increase of initial temperature, and the intensity of the reaction also increases with the increase of initial temperature. Temperature has an accelerating effect on their diffusion, and SnO2/SiO2/Al has stronger diffusion ability than Fe2O3/SiO2/Al. The Fe2O3/SiO2/Al aluminum thermite has a better damage effect on chips, and the simulation and experimental results are consistent.
研究领域:
材料科学
·
计算化学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2025
·
IF 4.6
Wenyu Li,Yajun Wang,Qiang Gan,Zhengliang Deng,Junhan Gao
Developing efficient oxidizers is critical for advancing nano thermites. Titanium oxyfluoride (TiOF 2 ) with oxygen/fluorine dual-active centers is innovatively employed as an oxidizer in Al/TiOF 2 composites prepared via physical mixing. Structural and morphology characterization confirms uniform interfacial contact while preserving component stability. The system demonstrates exceptional reactivity: onset and peak reaction temperatures (409.4°C, 470.0°C) are reduced by 139.1°C and 130.7°C, respectively, versus Al/TiO 2 , with activation energy lowered to 84.35 kJ·mol −1 . Synergistic F–O interactions impair reaction barriers, yielding 3692.2J·g −1 heat release (120 % increase over Al/TiO 2 ). Combustion tests reveal vigorous ignition under low energy input, rapid flame propagation, and two-stage spark ejection. This work reveals the activation mechanism of oxyfluoride as an oxidizer for thermites: fluorine enhances the reaction kinetics through an interfacial modification effect, while oxygen guarantees the energy density of the system. The synergy of the two elements realizes the optimization and regulation of combustion performance.
研究领域:
材料科学
·
化学工程
·
含能材料
·
纳米技术
·
燃烧化学
✓ 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）