COMBUSTION EXPLOSION AND SHOCK WAVES
·
2014
·Vol. 50
·期 6
·664-669
·
IF 0.486
Ao W.,Zhou J. H.,Yang W. J.,Liu J. Z.,Wang Y.,Cen K. F.
Ignition, combustion, and oxidation characteristics of mixtures of amorphous and crystalline boron powders are studied by using a laser ignition system and a thermogravimetric analyzer. Yellow, green, and white-glow flames are observed. When the weight ratio of the amorphous boron powder ( K ) is lower than 0.33, burning of the mixtures is found to be at the ignition stage, while the combustion stage gradually appears with increasing K . The emission spectrum intensity is weakened by 3/4 as K decreases from 1 to 0.75. No obvious emission spectrum is detected at K < 0.33. The ignition delay time is found to decrease significantly with increasing K , but it does not change much at K < 0.8. Mixtures with larger values of K have a lower peak temperature of differential thermal gravity and a greater weight gain and maximum reaction rate. The Satava-Sestak method is applied to study the kinetics of the oxidation reaction of the mixtures. The calculated apparent activation energy decreases from 297 to 191 kJ/mol as K increases from 0 to 1. For mixtures with K ranging from 0.23 to 0.75, the apparent activation energy mainly stays constant at a value of 280 kJ/mol.
研究领域:
材料科学
·
燃烧与热能工程
✓ 已验证
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2022
·Vol. 48
·期 3
·e202200277
·
IF 2.134
Yang-Fan Cheng,Yu-Le Yao,Dan-Yi Li,Zi-Han Li,Ying-Kang Yao
To study the effects of boron powders on the detonation performance of emulsion explosives, the explosion temperature field, shock wave parameters and explosion heat of emulsion explosives were studied. The differences of boron powders with and without microcapsule cladding on improving the explosion performance were also discussed. Experimental results showed that, when the mass ratio of boron powders increased from 0 to 20 mass %, the average explosion temperature, explosion pressure, positive impulse and explosion heat of boron-containing emulsion explosives increased at first and then decreased. When the content of boron powders was 16 mass %, the average explosion temperature, explosion pressure, positive impulse and explosion heat of emulsion explosives reached their maximum values of 2521 K, 0.0385 MPa, 7.11 Pa ⋅ s and 6335 kJ/kg, which were 22.2 %, 30.1 %, 43.0 % and 42.1 % higher than those of the pure emulsion explosive (Sample A), respectively. Furthermore, the explosion temperature, positive impulse and explosion heat of emulsion explosive with boron powder-microcapsule (Sample B5) were up to 2648 K, 7.65 Pa ⋅ s and 6694 kJ/kg, increased by 5.0 %, 7.6 % and 5.7 % when compared with those of emulsion explosive with 16 mass % boron powders (Sample B3). Therefore, micro-encapsulation technology could improve the detonation performance of boron-containing emulsion explosives, which would be helpful to the formula design of high energy emulsion explosives.
研究领域:
化学工程
·
爆炸力学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Jie Liu,Deqi Wang,Guozhen Xu,Fengsheng Li
Due to the high mass calorific value, boron powder is widely used in energetic material systems such as solid propellants and ignition powders. Especially, boron powder has very broad application prospects in the field of fuel-rich propellants. However, due to the cross-linking reaction between the boric acid contained on the surface of boron powder and an adhesive called hydroxylated polybutadiene (HTPB), the viscosity of the propellant mixture system increases sharply, which seriously affects the preparation of the propellant. In this paper, “click chemistry” is intended to be used to graft the functional groups on the surface of boron powder to reduce the viscosity of the boron powder and HTPB in the initial mixing stage. In addition, a rheometer was used to test the viscosity of the boron powder and the HTPB system. The test results showed that compared to the viscosity of the raw boron powder system at 24.1 Pa·s, the mixing termination viscosity of the grafted sample was 17.1 Pa·s, a decrease of 29.0%.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Crystals
·
2021
·Vol. 11
·期 3
·278
·
IF 2.589
Liangqun Yang,Hongli Suo,Lin Ma,Min Liu,Wanli Zhao,Jianhua Liu,Lei Wang,Zili Zhang,Qiuliang Wang
In this study, boron powder with different particle sizes was purified by both chemical and heat treatment methods. The reduction in the particle size can improve the chemical purification with no effort on the heat treatment. The superconducting properties of the powder drastically changed even with only a partial elimination of oxygen. On the one hand, less oxygen content resulted in highTcandJcvalues under the low magnetic field, and most importantly, a significant improvement in the superconducting connectivity (Afvalue). On the other hand, the degradation ofJcunder a high field and a change in the pinning mechanism were also found, along with decreasing oxygen. This result indicated that oxygen, probably MgO, might act as the pinning center and as an obstacle for the supercurrent in MgB2at the same time. This work paves the way for obtaining pure oxygen-free MgB2and understanding the real effect of oxygen in MgB2.Keywords:boron powder;purification;particle size;MgB2;superconducting connectivity
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Journal of Energetic Materials
·
2022
·
IF 2.421
Shu-Ji Wang,Di Wang,Ping Liu,Xiao-le Sun,Shi Yan,Xue-Yong Guo
TKX-50, as a representative of a new nitrogen-rich energetic compound, has attracted extensive interests due to its high energy and low sensitivity properties. As an important energetic material, combustible agent has great influence on improving the energy level of explosives and propellants. Boron powder has become the most potential combustible agent in energetic fields because of its unique performances. In this work, nano-boron-based microspheres containing TKX-50 are directly fabricated by electrospray deposition. The prepared microspheres showed high monodispersity with particle size ranging from ~1–3 μm. Thermal behavior results show that the mass gain of the electrostatically sprayed sample is 163.3%, which is much higher than that of pure boron and physically mixed samples. Combustion behavior tests show that electrosprayed microspheres exhibit outstanding performance in comparison to physical mixed sample, the peak pressure improved by 85%, the burning time decreased by 21% and the pressurization rate improved by 136%. These excellent properties are probably related to their uniform microstructure. Therefore, electrospray preparation of microspheres with controllable structure has a good application prospect in energetic materials.
研究领域:
化学
·
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Hailong Zhou,Jiuyu Chen,Yunlan Sun,Naiqiang Huang,Jiang Liu,Xuan Jiang,Baozhong Zhu
Boron (B) powder has been considered a promising high-energy material due to its high calorific value. Nevertheless, the low combustion efficiency and the difficulty in ignition restrict its application. To solve the problems, in this study, an energetic metal-organic framework (EMOF) was used as a modifier for the nano-sized B powder, and its effect on the ignition and burning performance of B powder was examined. EMOF can significantly increase the heat release of B powder and lower its initial oxidation temperature. The best improvement is achieved with 10% EMOF contents in air, while the highest heat release is obtained with 25% EMOF contents in pure oxygen. Furthermore, EMOF can also reduce the ignition delay of B powder, enhance the flame intensity, and increase the flame propagation rate. This study offers new perspectives on modifying B powder with incorporating EMOF to develop multifunctional energetic particles with improved ignition and combustion characteristics.
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2023
·
IF 3.5
Lijuan Yan,Baozhong Zhu,Xiaohan Yan,Wenhua Wang,Jiuyu Chen,Jun Liu,Yunlan Sun
Boron (B) is an ideal fuel due to its high mass and volumetric calorific values. However, its high ignition temperature and poor combustion efficiency affect its wide use in propellants. Nickel oxide (NiO) has been found to possess strong catalytic activity as a metal oxide in a transition state. In this study, composites of three different particle sizes of B particles and various concentrations of NiO were prepared. Thermal analysis, combustion process, and combustion mechanisms were investigated. Modifying B with NiO can decrease the initial oxidation temperature and ignition temperature. The flame temperature and combustion efficiency are increased after B powder is modified by NiO. The mechanism of the combustion reaction was further investigated to gain a deeper understanding of the NiO-catalyzed B oxidation process.
研究领域:
材料科学
·
燃烧学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Energetic Materials Frontiers
·
2023
·
IF 0
Yu-shu Xiong,Yong-qi Wang,Chong Wan,Wen-zhen Zhang,Zhao Qin,Su-hang Chen,Kang-zhen Xu
To overcome the agglomeration and insufficient combustion of nano-boron (n-B) powders, this study successfully prepared two novel types of boron-based nanocomposites using the acoustic resonance technology, namely high-substitute nitrochitosan/nano-boron (NCh-B) with ratios of 1:3, 1:5, 1:7 and 1:9, and nitrochitosan/nano-boron powder/nano-titanium (NCh-B-Ti) with Ti contents of 5 wt%, 10 wt%, 15 wt% and 20 wt%. The structural morphologies, laser ignition and combustion properties of the composites were systematically investigated. The results suggest that the addition of NCh can significantly improve the dispersion of n-B. NCh-B exhibited a higher combustion performance than n-B, as evidenced by their ignition delay and flame areas. When the laser power density was 81 W, NCh-B 5 -Ti 15% exhibited a combustion time and an ignition delay of 240 ms and 5.5 ms respectively, which were higher and lower than those of NCh-B 5 (199 ms and 17 ms, respectively). Furthermore, NCh-B 5 -Ti 15% displayed a lower ignition delay than both n-B powders (12 ms) and NCh-B (11 ms), as well as brighter flames and a larger combustion area. Therefore, the addition of n-Ti can promote the combustion of n-B powders, with the combustion products of NCh-B-Ti including H 3 BO 3 , B 2 O 3 , TiB 2 , and TiO. This study provides a new method for improving the ignition performance and combustion efficiency of n-B powders.
研究领域:
材料科学
·
燃烧学
✓ 已验证
DOI
Chinese Journal of Aeronautics
·
2023
·
IF 5.7
Lingqi ZHU,Baozhong ZHU,Xiaolong ZHAO,Yanan WANG,Mengchen LI,Jiuyu CHEN,Yunlan Sun
Boron has a promising application in the field of propellants due to its high calorific value. However, the difficulty of ignition and the poor combustion efficiency of boron (B) have severely limited its efficient application. In response to this issue, this paper proposes to improve the ignition and combustion performance of micron-sized boron by the Polyvinylidene Fluoride (PVDF) coating. The effect of PVDF content on the B combustion performance was systematically studied using a Thermogravimetry-Differential Scanning Calorimetry (TG-DSC), a Transmission Electron Microscope (TEM), an X-Ray Diffractometer (XRD), a laser Particle Size Analyzer (PSA), and a high-speed camera. The results show that PVDF can significantly reduce the initial oxidation temperature of B powder and increase its reaction heat. When the PVDF content is 23wt%, the reaction heat and the combustion intensity of B powder reach the maximum and are significantly higher than those of the uncoated B powder. Moreover, the fluorination reaction that occurs during the combustion process not only can effectively shorten the combustion time of B powder, but also has a positive effect on its flame intensity and propagation speed, and it significantly reduces B particle agglomeration, which improves the combustion efficiency significantly. This study lays the foundation for the application of PVDF modified B in B-based solid propellants.
研究领域:
材料科学
·
燃烧学
·
推进剂技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 36
·17145-17161
·
IF 3.5
Huang Naiqiang,Zhu Baozhong,Yang Tianyu,Chen Jiuyu,Sun Yunlan
Boron (B) powder is considered to be an excellent fuel for propulsion applications due to its remarkable energy density. However, B is severely affected by boron oxide (B 2 O 3 ) on its surface. To solve this problem, polyvinylidene fluoride (PVDF) and copper oxide (CuO) coatings were applied onto B particles, leveraging their synergistic effects to enhance the ignition and combustion performance (ICP) of B. Various characterization methods and CO 2 laser ignition experiments were used to determine how PVDF and CuO impact B combustion. PVDF and CuO are helpful to improve the ICP of B. Especially for the (B/CuO 4 )@PVDF 16 sample, it exhibits 28.2% higher combustion heat, 46.4% shorter ignition delay, and flame expansion rate (FER) increases from 0.091 to 0.280 m s −1 versus unmodified B. Furthermore, PVDF suppresses B powder agglomeration during combustion. The present work provides a new idea for improving the combustion of B powder. Graphical abstract
研究领域:
材料科学
·
燃烧与推进
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2025
·
IF 6.2
Yang Chen,Junfei Ou,Tianyu Yang,Baozhong Zhu,Yunlan Sun
The restricted energy release efficiency has been a significant hindrance to the utilization of boron (B) powder as a fuel in solid propellants because of the presence of oxidation film on the B surface. To address this issue, poly (vinylidene fluoride-co-hexafluoropropylene) (Viton A) and glycidyl azide polymer (GAP) were used for the collaborative modification of micron-sized boron (µB) powder. The thermal oxidation, ignition, and combustion performance of µB before and after modification were investigated by thermogravimetric-differential thermal analysis (TG-DTG), differential scanning calorimetry (DSC), and carbon dioxide laser ignition testing. The dual-layer coating interface structure of B@Viton A@GAP is more conducive to reducing the ignition delay time, accelerating the flame expansion rate, enhancing the combustion intensity, improving the combustion efficiency, and reducing agglomeration of combustion products of B powder. The study offers an effective method to promote the combustion of B through its modification with Viton A and GAP.
研究领域:
材料科学
·
燃烧与推进
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Lijun Qin,Dan Li,Yiyun Hu,Qiuhong Wang,Ting Gong,Jian Zhang,Hao Feng
Boron has emerged as a highly attractive high-energy fuel/additive for multi-scenario applications including powder ramjet engines and rocket propellants, owing to its exceptional calorific value. However, the inherent surface oxide layer impedes oxygen diffusion during combustion, resulting in ignition difficulties and incomplete combustion. This study provides a methodology for constructing titanium oxide activation layers on boron particles via atomic layer deposition (ALD), with systematic investigation of how coating thickness (precisely controlled at 0.046 nm/cycle) influences thermal oxidation behavior and ignition characteristics through multi-technique characterizations. It is demonstrated that complete and uniform encapsulation of boron particles was achieved by TiO 2 nano-coatings. Compared to pristine boron, ALD TiO 2 -activated specimens exhibit significant performance enhancements including reduced oxidation temperature (ΔTp = 133 °C), shortened laser ignition delay (32 % reduction), minimized ignition energy of dust clouds (over 90 % decrease), and accelerated flame propagation velocity in dust clouds (one order of magnitude increase). Mechanistic analysis reveals that these improvements originate from a synergistic oxygen transport mechanism between oxygen vacancies in TiO 2 and B 2 O 3 -TiO 2 solid-solution interfaces. The uniformly distributed TiO 2 surface modification layer establishes sustainable oxygen transport channels through surface vacancy defects, maintaining stable oxygen concentration at reaction interfaces and thereby accelerating boron oxidation kinetics. This work provides both theoretical foundations and practical engineering solutions for overcoming critical bottlenecks in boron-based energy applications.
✓ 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）