PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2021
·Vol. 46
·期 10
·1598-1610
·
IF 1.887
Xiaoxia Ma,Xi Chen,Yuxiang Li,Zhiqiang Qiao,Guangcheng Yang,Kaili Zhang
The afterburning effect of aluminized explosives makes them have strong damage ability to soft targets, but the aluminum particles in the composition often cannot achieve proper combustion. The high ignition temperature of micron aluminum powder is one of the main reasons. In this work, we introduce nanothermite reaction with low onset temperature (<660 °C) into aluminized explosives by replacing the base explosives with energetic coordination polymers (ECPs). The decomposition products of many ECPs contain corresponding metal oxides that will react with aluminum via thermite reaction. Three kinds of ECPs ([CoC 2 H 4 N 8 O 4 ] n , [NiC 2 H 4 N 8 O 4 ] n and [CuC 2 H 4 N 8 O 4 ] n ) are constructed and compounded with nano-aluminum (nano-Al) particles to form aluminized ECPs. The influence of metal ion species and Al/Metal (Al/Me) molar ratio on their energetic properties are systematically studied. The results show that the exothermic thermite reaction with low onset temperature plays an important role in the combustion propagation of aluminized ECPs, and the possible mechanism is proposed. When the Al/Me molar ratio is 3–4, the aluminized ECPs have the best peak pressure and pressurization rate. At the optimum molar ratio, the pressure and pressurization rate of aluminized ECP(Co) are much higher than those of aluminized ECP(Ni) and ECP(Cu). Among the three kinds of aluminized ECPs, the aluminized ECP(Co) has the best energetic characteristics and can be used as a preferred choice. However, for the applications that require a long-time heat supply, aluminized ECP(Cu) will be suitable.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
BMC Chemistry
·
2024
·Vol. 18
·期 1
·1-13
·
IF 4.3
Chen Jialin,Li Shutao,Dai Mengnan,An Ming,Song Rui,Chen Yeqing,Song Jiaxing,Tian Quanwei,Zhong Xiting,Yan Qiushi
To improve the thermal and combustion properties of nanothermites, a design theory of changing the state of matter and structural state of the reactants during reaction was proposed. The Al/MoO 3 /KClO 4 (Kp) nanothermite was prepared and the Al/MoO 3 nanothermite was used as a control. SEM and XRD were used to characterize the nanothermites; DSC was used to test thermal properties; and constant volume and open combustion tests were performed to examine their combustion performance. Phase and morphology characterization of the combustion products were performed to reveal the mechanism of the aluminothermic reaction. The results show that the Al/MoO 3 /Kp nanothermite exhibited excellent thermal properties, with a total heat release of 1976 J·g − 1 , increasing by approximately 33% of 1486 J·g − 1 of the Al/MoO 3 nanothermite, and activation energy of 269.66 kJ·mol − 1 , which demonstrated higher stability than the Al/MoO 3 nanothermite (205.64 kJ·mol − 1 ). During the combustion test, the peak pressure of the Al/MoO 3 /Kp nanothermite was 0.751 MPa, and the average pressure rise rate was 25.03 MPa·s − 1 , much higher than 0.188 MPa and 6.27 MPa·s − 1 of the Al/MoO 3 nanothermite. The combustion products of Al/MoO 3 nanothermite were Al 2 O 3 , MoO, and Mo, indicating insufficient combustion and incomplete reaction, whereas, the combustion products of Al/MoO 3 /Kp nanothermite were Al 2 O 3 , MoO, and KCl, indicating complete reaction. Their “coral-like” morphology was the effect of reactants solidifying after melting during the combustion process. The characterization of reactants and pressure test during combustion reveals the three stages of aluminothermic reaction in thermites. The excellent thermal and combustion performance of Al/MoO 3 /Kp nanothermite is attributed to the melt and decomposition of Kp into O 2 in the third stage. This study provides new ideas and guidance for the design of high-performance nanothermites.
研究领域:
材料科学
·
燃烧学
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Zili Ma,Yanjun Yin,Fan Li,Jinpei Hei,Yongji Wang,Yang Zhang
Aluminum (Al), with its abundance and high energy release, has attracted great interest in nanocomposite energetic systems. However, the ignition temperature and combustion performance of Al-based thermites are limited by the oxide shell coating on the Al core. A novel metal carbodiimide oxidizer has been employed to assemble thermite with superior energy release in comparison with metal-oxide-based thermite. In this work, titanium (Ti) nanoparticles have been incorporated into the Al/CuNCN system with virous mass ratio (from 0 % to 100 %) to adjust their energetic behavior in comparison with traditional Al/CuO. The component, structure and morphology of the energetic composites were charactered by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectrophotometry (FT-IR). The temporal pressure traces and heat release of Al/Ti/CuNCN and Al/Ti/CuO composites have been measured via combustion cell and calorimetry, respectively. The over pressure of Al/30 %Ti/CuNCN reached to be 80 KPa, which is higher 9 KPa than the maximum pressure of Al/Ti/CuO. The energy release for both Al/Ti/CuNCN and Al/Ti/CuO proved to be lower than that of Al or Ti with oxides (CuO or CuNCN) owing to the alloying reaction. The high pressure of Al/Ti/CuNCN may offer the potential routes to prepare gas generators, and the results would be an essential guide in designing thermites. Besides, the metal nitrides such as AlN, TiN, Ti 9 N 3.87 were obtained in the aluminothermic reaction, providing new possible for the preparation of novel materials following a self-propagating route within one second.
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
Materials Today Communications
·
2025
·
IF 4.5
Wenyu Li,Yajun Wang,Ruihua Liu,Qiang Gan,Zhengliang Deng
Nano-thermite technology stands as a pivotal domain within the field of energetic material research. This study is to explore the innovative utilization of oxyfluorides as oxidants in thermites. High-purity FeOF was synthesized through a solvothermal approach and subsequently physically blended with aluminum (Al) to formulate a novel Al/FeOF nano-thermite. To shed light on the underlying reaction mechanisms, we conducted a comparative analysis of the thermal properties, activation energies, and combustion performances of the Al/FeOF nano-thermite against control samples, namely Al/Fe₂O₃, Al/FeF₃, and Al/Fe₂O₃/FeF₃. Under an air atmosphere, the heat release results revealed that the Al/Fe₂O₃ system released 2692.5 J·g⁻¹ of heat, while the Al/FeF₃ system released 1477.6 J·g⁻¹ . The heat release of the Al/Fe₂O₃/FeF₃ system further decreased to 1030.9 J·g⁻¹ . In stark contrast, the heat release of the Al/FeOF system significantly increased to 3011.9 J·g⁻¹ , highlighting a substantial difference among these systems. These findings imply that during the reaction process, there exists a competitive relationship between the independent metal oxide and metal fluoride. Conversely, when oxygen and fluorine coexist within the same material (FeOF), a distinct synergistic effect becomes evident. Analysis of the onset reaction temperatures demonstrated that the Al/Fe₂O₃ system initiated the reaction at 539.2 °C, the Al/FeF₃ system at 463.8 °C, the Al/Fe₂O₃/FeF₃ system at 572.6 °C, and the Al/FeOF system at 547.9 °C. These suggest that the co-presence of O and F reduces the competitive influence typically observed between fluorides and oxides. Moreover, the Al/FeOF system exhibited the lowest activation energy (170.57 kJ·mol⁻¹), the shortest ignition delay (15.3 ms), and the briefest combustion time (59.7 ms). These superior characteristics underscore its exceptional thermal stability and combustion performance.
研究领域:
含能材料
·
纳米技术
·
材料化学
·
铝热反应
✓ 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）