COMBUSTION AND FLAME
·
2024
·
IF 5.8
Peihui Xu,Xingang Dong,Wenke Zhang,Yuxin Yang,Xueqin Liao,Jianzhong Liu
Overcoming the difficulty of ignition and combustion of aluminium in water vapour is the key to being applied in underwater propellant applications. The effect of coating or blending 20 mass% ammonium perchlorate (namely, AP@Al or AP–Al samples) on the ignition and combustion of Al particles in a 1.0 MPa water vapour–Ar environment was investigated using a constant temperature pressurized combustion chamber and a CO 2 laser. The results show that the combustion of Al particles in a water vapour–Ar environment is a non-homogeneous reaction and that agglomeration processes of Al droplets are observed. The ignition and combustion properties of the AP@Al and AP–Al samples under water vapour were greatly improved due to the decomposition of AP for heat/oxygen (particularly, O 2 provided a new pathway for AlO(g) generation) supply and the effect of dispersed particles. The maximum pressure change and combustion temperature ( T max ) were increased significantly for the AP@Al and AP–Al samples combustion, while their ignition delay time ( t i ) and combustion time ( t c ) decreased remarkably. In addition, the coating form is more effective in the combustion-promoting effect of AP than the blending form. Interestingly, the increase in water vapour concentration is not conducive to the ignition and combustion of samples in this work. It is probably because the reaction system is lean-fuel where the excess water vapour absorbs some of the heat and prevents effective collisions among the radicals. In addition, the chemical equilibrium largely influences the combustion temperature, resulting in a conspicuous effect of changes in water vapour concentration on the T max values. The reaction interface largely influences the combustion reaction rate of Al, so changes in particle size have a significant effect on the t i and t c values.
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2023
·
IF 5.4
Jiao Li,Jian Zhang,Hongyu Zhang,Xuwen Wang,Taojie Lu,Jiayan Liang,Yulin Yang,Kaifeng Lin,Debin Xia
Interface modification of aluminum particles plays a crucial part in reducing the agglomeration during the combustion of solid propellants . In this study, the aluminum (Al) particles are pretreated with gallic acid (GA) to get Al@GA with an adhesion-favorable surface, which facilitates the further coating procedure. One new fluorine-containing organic substance is prepared, namely p-HFBA. The p-HFBA further coats the Al@GA to produce Al@GA/p-HFBA. The interface between Al@GA and the coating layer p-HFBA forms Al F bonds and induces a pre-ignition reaction with an aluminum oxide shell. Hence, the agglomerate size of propellants containing Al@GA/p-HFBA significantly decreases from 176.30 μm to 84.72 μm. The agglomerates volume is reduced by approximately 97 %. Additionally, more gaseous products investigated by TG-MS provide the Al particles with greater impetus (aerodynamic forces, F ae ), enabling them to leave the burning surface and reduce the residence time. The rise in F ae and drop in adhesion force ( F ad ) effectively reduce the agglomeration intensity according to the skeleton layer model. This work proves that interface modification can effectively enhance the combustion performance of aluminized solid propellants .
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
COMBUSTION AND FLAME
·
2025
·
IF 6.2
Xueqin Liao,Peihui Xu,Mengxia Sun,Fan Zhang,Jianzhong Liu
Aluminum (Al) particles are widely used in propellants, thermite and explosives. However, its energy release process is still not thoroughly investigated. In this paper, the reaction properties of Al particles at low and high heating rates were investigated using a thermal analysis system and a single-particle combustion system, respectively. At a low heating rate (10°C/min), when the temperature is raised to 1200°C, the oxidation efficiency of Al (which can also be regarded as the average oxidation rate) increases first and then decreases as the oxygen concentration increases. In addition, XRD results of intermediate oxidation products under air show that the oxidation of Al particles deepens with increasing temperature. The SEM results reveal that broken particles and large-size aggregates gradually appear in the sample as the temperature increases, and the surface of the Al particles becomes rougher. At high heating rate (combustion), with the increase of oxygen concentration, the probability of microexplosion of Al particles increases from 19.77 % under air to 82.67 % under 100 % O 2 . Furthermore, the combustion time gradually decreases with the increase of oxygen concentration, while the average mass burning rate gradually increases from 1.65 g/ms under air to 2.73 g/ms under 100 % O 2 . Based on the analysis of the surface structure of the intermediate oxidation products and the microexplosion of single particles, it is believed that the difference of the reaction law of Al particles at different heating rates may be related to the structural evolution behavior of the oxide film. This study provides basic data support for understanding the heat release behavior of Al particles.
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2025
·
IF 3.5
Xueqin Liao,Binghong Chen,Qiaoyu Zhang,Zehao Li,Jianzhong Liu
Herein, a thermal analysis system and a laser combustion diagnostic system were employed to comparatively investigate the reaction behavior differences of Al particles in N 2 and oxidizing atmospheres. The results show that Al particles have higher mass gain and heat release in N 2 compared to air and carbon dioxide at low heating rates. When the temperature is increased to 1000 °C, the reaction efficiency of Al in nitrogen is as high as 56.68%, much higher than that of 16.02% for air and 17.41% for carbon dioxide. Broken particles and large-sized agglomerates are found in the intermediate nitride products, and the particle surfaces become loose and porous. Combustion test results show that the combustion performance of Al particles in air is better than that in N 2 . Nanoscale smooth spherical alumina particles are found in the condensed combustion products of Al particles under air. Whisker-like aluminum nitride (AlN) is observed under nitrogen.
研究领域:
材料科学
·
燃烧学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Bo Yang,Jianping Deng,Liyan Wei,Yanni Han,Gang Yu,Shubo Deng,Caizhen Zhu,Huabo Duan,Qiongfang Zhuo
2,2′,4,4′-Tetrabromodiphenyl ether (BDE47) is known as a recalcitrant bromated organic pollutant with the significant persistence, toxicity, and bioaccumulation. In this study, a synergistic effect of ball-milled Al particles with vitamin B 12 on the degradation of BDE47 was found according to the coordinated catalytic reduction process. The micro-scale Al particles prepared by ball milling and vitamin B 12 as common pharmaceutical composed a new combination reagent for hydrodebromination with low-cost and high reactivity. The degradation conditions were optimized by the addition of 2.0 g/L BM Al particles and 0.3 mM VB 12 using the solvent of methanol/H 2 O (v:v = 40:60) at pH 4.0. More than 97% of 25 mg/L BDE47 was debrominated into lower-brominated diphenyl ethers in a sequential pattern and finally into diphenyl ethers within a 120-min reaction. UV/Visible spectra showed that vitamin B 12 (Co(III)) was reduced to vitamin B 12s (Co(II)) by the ball-milled Al particles, which possesses super nucleophilic property to associate the carbon atom on C Br bond and then facilitates the hydrodebromination process of brominated diphenyl ethers. The experimental results can provide basic understanding to identify a reaction process of vitamin B 12 /vitamin B 12s for the enhanced reductive debromination of polybrominated diphenyl ethers by ball-milled Al particles, which would be possibly applied to treat soil washing solvent in the field of soil remediation.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2022
·
IF 4.865
Jingyan Wang,Yaning Li,Zhiwei Han,Saichao Song,Jian Li
Oxidants, such as oxygen, cannot easily approach the core Al due to the presence of dense alumina on the surface of aluminum particles, thereby resulting in high ignition temperature and long ignition duration. To overcome this challenge, we employed the solvent/non-solvent method using Viton A (a copolymer of 1,1-difluoroethylene and hexafluoropropylene) as a coating material to prepare the core-shell Al/Viton A composite particles . An orthogonal experiment was designed to identify the optimal preparation parameters by evaluating the peak pressure in a closed vessel. The sample with the largest peak pressure was compared with raw Al and Al/Viton A (prepared by the physical mixing method) using the combustion pressure and open combustion tests to evaluate the solvent/non-solvent method. The results from the orthogonal experiment revealed that the water bath temperature exhibited the greatest influence on the coating effects. The composite prepared under a water bath temperature of 55 °C and a stirring rate of 250 rpm, using 20 mL of acetone and a 5 mL/min dripping rate of the Viton A acetone solution, were uniformly coated by Viton A, and exhibited excellent combustion characteristics. In addition, the sample generated using the optimal preparation parameters burnt more vigorously and rapidly than raw Al and Al/Viton A. Finally, the reaction molecular dynamics simulation was employed to gain insight into the effect of Viton A on the combustion of Aluminum particles at the molecular level.
研究领域:
材料科学
·
燃烧化学
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2025
·
IF 4.6
Xueqin Liao,Jianzhong Liu,Mengxia Sun,Xiaohui Xue
Fluoride has shown great potential for improving the burning rate and combustion efficiency of aluminum (Al) particles. Herein, the effects of metal fluoride (ferric fluoride, FeF 3 ) and organic fluoride (polytetrafluoroethylene, PTFE) on the combustion of Al particles were comparatively investigated using various characterization methods. The results showed that both FeF 3 and PTFE could improve the thermal reaction properties of Al particles, including thermal oxidation rate, heat release, mass gain, and thermal oxidation efficiency, and the improvement of FeF 3 was better. Thermal reaction curves and tube furnace tests together demonstrated that fluoride and Al particles undergo pre-ignition reaction at low heating rates. Combustion diagnostic results and condensed combustion products (CCPs) analysis of the samples revealed that both fluorides reduced the ignition delay time and increased the combustion intensity, burning rate, combustion efficiency and maximum combustion temperature. When ammonium perchlorate (AP) was not added, PTFE improved the combustion performance of Al particles better due to its high gas production characteristics. PTFE is not as good as FeF 3 after adding AP. Furthermore, varying the FeF 3 content in the binary mixture (Al/FeF 3 ) between 5 % and 20 % did not significantly affect the combustion characteristics of the samples. Interestingly, the high-speed camera captured the jetting phenomenon of Al droplets during combustion, which is attributed to the erosive effect of F on the alumina cap. The jet phenomenon is the direct evidence of the reaction between Al particles and F during combustion, which provides new insights into the complex reaction mechanism between the two. Statistics on a large number of particles indicated that FeF 3 can increase the frequency of the particle jet phenomenon. Finally, the phenomenological mechanism of fluoride promoting Al particle combustion is proposed. Considering the catalytic effect of metals and their corresponding oxides on AP, the addition of metal fluorides to AP-based energetic materials may be a more preferable option.
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Chao Wang,Ying Liu,Kang Niu,Jia Li,Qing Cao,Xiuchen Zhao,Hongyang Li,Ningfei Wang,Baolu Shi
To improve the combustion efficiency of widely used micro-aluminum (μAl) particle, enhancing its ignition and combustion performances is a critical issue via breaking through the intrinsic Al 2 O 3 layer covering the Al-core. This study proposed a facile in-situ ‘one-pot’ electroless plating method to functionalize the surface of μAl particles with ternary-shelled nickel-phosphorus-copper alloy coating and furthermore investigated the thermochemical and ignition/combustion behaviors of energetic core–shell composites (defined as Al@Ni-P-Cu). The microstructure characterization results of Al@Ni-P-Cu demonstrated that a spherically distributed triple-shell Ni-P-Cu alloy with the thickness of 129 nm was tightly coated on μAl particle surface. Through TG-DSC analysis, the Al@Ni-P-Cu composites exhibited improved heat release (7597.7 J/g) and decreased initial oxidation temperature (814.3 °C) in comparison to that of μAl particle with 949.2 J/g and 960.1 °C, respectively. The Al@Ni-P-Cu exhibited extremely shorter laser ignition delay time of 36.3 ms under 1 MPa O 2 atmosphere, reducing by 86.86% compared with that of raw μAl particles (276.3 ms); and its maximum flame temperature could reach up to 1588.93 °C, increasing by 243.36 °C compared with that of μAl (1345.57 °C). The drastic improving performances were attributed to the synergistic effects of surface/interfaces reactions along with heat release in the core–shell structure, resulting in enhanced mass and heat transfer to facilitate the combustion of internal Al-core.
研究领域:
材料科学
·
燃烧学
✓ 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）