COMBUSTION AND FLAME
·
2024
·
IF 5.8
Jiabao Zhu,Shuo Wang,Weiqiang Xiong,Jun Wang,Xiaodong Li,Meishuai Zou
Aluminum-lithium alloy powder exhibits better thermal properties and combustion performances than aluminum , thus showing promising applications in the field of energetic materials such as explosives and propellants. However, the high activity of lithium also raises issues of stability and compatibility with propellant components, deteriorating the powder's overall performance. In this study, a facile coating method is presented using 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTS) as a surfactant to coat hydroxyl‑terminated polybutadiene (HTPB) on the surface of Al-5Li powder, forming the core-shell composite Al-5Li@HTPB. The microstructure and chemical composition characterized by SEM, EDS , XPS , FT-IR, and nano-CT demonstrated that a uniform and dense layer was successfully coated on the surface. The thermal analysis results showed a significant improvement in the thermal properties and stability compared to pure Al-5Li. In addition, ignition tests were conducted, and the results showed that Al-5Li@HTPB could reduce the ignition delay time and significantly reduce agglomeration. Overall, our strategy provides a novel method to solve the stability issues of Al-Li powders and simultaneously enhance combustion performance.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Haiyang Wang,Shuo Wang,Xuanyan Liu,Youqi Zhu,Tinglu Song,Haiyue Yu,Hongdi Fu,Kangcheng Xu,Huaqiang Zhu,Yonghao Zhao,Siyuan Tang,Meishuai Zou
Aluminum-lithium alloy powders receive extensive concern as metal fuel in propellants for high heat value and coefficient of combustion. However, the presence of highly active metal lithium leads to the instability of alloy powder, limiting its application in propellants. Herein, the fluorination-energetic modification is developed to solve the activity problem of aluminum–lithium alloy (Al-5Li, Li 5 wt%) powders and increase their energy level. The first fluorinated layer is constructed by fluorosilane and epoxy silane coating to achieve the modifiable and functional aluminum–lithium alloy (Al-5Li@FS). Afterwards, the energetic layer is coated on Al-5Li@FS surface by glycidyl azide polymer (GAP) to obtain the fluorination-energetic composite powders (Al-5Li@FSG). The microstructural and chemical composition characterizations of Al-5Li@FSG are performed by SEM, FTIR, XPS, TEM, and TOF-SIMS. TG-DSC results show that the coated alloy powders can exhibit excellent thermal properties with remarkably enhanced exothermic enthalpy and thermal weight gain. The Al-5Li@FSG shows significantly improved combustion performances with reduced ignition delay time and repressed agglomeration phenomenon. Furthermore, hydrophobicity, water-reactivity, and compatibility with propellant components are also well modified of the Al-5Li@FSG. This work provides a guideline for preparing aluminum–lithium alloy powders with remarkable stability, excellent combustion performance, compatibility, and high energy level.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wei Le,Wanjun Zhao,Yanli Zhu,Ziting Wei,Zhigang Liu,Dazhi Liu,Qingjie Jiao
As a highly reactive metal fuel, aluminum–lithium (Al-Li) alloy is an ideal candidate for replacing Al powders in solid propellants. However, the Li solid solution and AlLi compounds on the surface of Al-Li alloy powders display high reactivity, which can react with a large number of organic and inorganic reagents. Thus, the incompatibility of Al-Li alloy with other components of propellants makes it difficult to be further applied in propellants. In this study, surface-modified Al-Li alloy powders (Li content of 5 wt%) with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS17) were prepared by a facile self-assembly method, which made the alloy powders super-hydrophobic. The results of SEM, XPS and FIB-TEM show that the surface of Al-Li alloy powder is well-coated by an evenly distributed FAS17 layer. Due to the fluoroalkyl on the surface of the powders, the water contact angle increased by 91°and the intensity of the reaction between alloy powders and water is significantly reduced, which results in improved compatibility with other components of propellants. Meanwhile, the propellant grain of surface-modified powders had fewer defects than the sample before coating, and showed original excellent combustion performance. The average combustion pressure and pressurization rate increased by ∼114 kPa and ∼8613 kPa/s, and the steady burning rate increased by 0.24 mm/s. Therefore, the surface-modified Al-Li alloy powders with FAS17 are expected to be an attractive candidate as a highly active and stable fuel in solid propellants.
研究领域:
材料科学
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化学工程
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2020
·Vol. 45
·期 7
·1141-1152
·
IF 1.544
Zhengyu Cao,Aobo Hu,Bin Xia,Ai-min Pang,Shuizhou Cai
Aluminum-lithium alloy powder has broad application prospects in the field of energetic materials due to its good thermal performance. However, the high reactivity of lithium and the incompactness of the surface oxide layer result in the continuous oxidation of the active metal during storage, thereby deteriorating the thermal performance of the powder. In this paper, a layer of polystyrene (PS) was successfully coated on the surface of Al-10Li (10 wt.%) alloy powder by in-situ polymerization of styrene (St). According to an orthogonal test, the optimum coating conditions for protection factor were as follows: m(St)/m(Al-10Li) was 1 : 1; m(AIBN)/m(St) was 5 %; the reaction temperature was 75 °C; the reaction time was 4 h. The structure, surface morphology and thermal properties were characterized by XPS, FTIR, SEM and TG-DTA. Furthermore, the aging stability of powders were studied by TG-DTA. The results showed that the decay rate of the weight increase of the active metal of Al-10Li alloy powder decreased significantly after coating, which demonstrated that the polystyrene coating effectively protected the active metal of Al-10Li alloy powder, prevented pre-oxidation of Al-10Li alloy powder in air and improved its storage stability.
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
危险品化学品经营许可证（带存储）