ENERGY & FUELS
·
2017
·
IF 3.091
Baozhong Zhu,Fan Li,Yunlan Sun,Yuxin Wu,Qichang Wang,Qi Wang,Weikang Han
To improve the ignition and combustion characteristics of micrometer-sized aluminum powder in steam at 900 °C, the present study focuses on the effects of adding different contents of Mg, NaF, and NaBH4. Experiments were conducted in two high-temperature tubular resistance furnaces to measure ignition temperatures, maximum combustion temperatures, and ignition delay times and to understand the combustion features of all samples. The experimental results show that Mg addition results in a reduced ignition temperature and ignition delay time of the micrometer-sized aluminum powder and causes two burning stages (a double-peak feature) because the Mg powder preferentially ignites before the micrometer-sized aluminum powder. The maximum combustion temperature increases with increasing Mg content. The ignition temperature and the ignition delay time are also significantly decreased with increased NaF or NaBH4 addition. However, the addition of NaF or NaBH4 lowers the maximum combustion temperature. The morphology, components, and residual aluminum contents of the solid combustion products are analyzed by scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. The combustion efficiency is slightly improved with the addition of NaF. The different mechanisms by which the additives influence the ignition and combustion of micrometer-sized aluminum powder are believed to underlie these experimental results.
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2019
·
IF 4.046
Jun Chang,Cang Xiong,Yangyang Zhang,Dan Wang
The present paper discusses investigated the foaming behaviors and microstructure of three aerated steel slag block (ASSB) samples prepared with three different foaming agents (namely animal protein, hydrogen peroxide, aluminum powder) and by accelerated carbonation. The composition and microstructure of the ASSB samples before and after accelerated carbonation were characterized using X-ray diffraction (XRD), Rietveld method, thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM). It is an advisable method for foamed steel slag products to use the aluminum powder and accelerated carbonation technology. The aluminum powder favored a good foaming behavior for steel slag owing to (i) a high porosity and low dry density, (ii) a high hydration degree of minerals in steel slag, including brownmillerite, larnite, and lime, which was confirmed by the analysis of mineral compositions using Rietveld method, and (iii) the interlaced lamellas of monocarboaluminate and calcium silicate hydrate (C-S-H) gel strengthen the bubbles wall, which was confirmed by morphology analysis using FE-SEM. After accelerated carbonation, the monocarboaluminate shifted to aragonite, vaterite, calcite and amorphous aluminum hydroxide (Al(OH) 3 ), which was confirmed by XRD, TGA and FT-IR. The network skeleton formed by aragonite crystals improved the compressive strength of ASSB prepared by aluminum powder. In addition, the reactions of the formation and carbonation of monocarboaluminate phase were proved to be thermodynamically possible in this work.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Yeming Huang,Jingxuan Zhang,Renhong Wang,Bing Gao,Ruyi Miao,Sirun Zhang,Dunju Wang
Improving the energy release efficiency of aluminium powders in weaponry is essential. In this study, uniform core-shell Al@(PFDTES/GAP) was prepared by hydrolyzing PFDTES and co-reacting it with GAP on aluminum powder. It showed better thermal reaction, combustion and energy release. The thermal properties of Al@(PFDTES/GAP) exhibit a significant aluminum-fluorine exothermic phenomenon in DSC, with a 4.9 % increase in exothermic heat in the combustion test compared to raw-Al. For the samples blended with PTFE, Al@(PFDTES/GAP)/PTFE demonstrated excellent performance in terms of increased heat release (increased by 28.0 %) in DSC, higher heat release (increased by 10.2 %) in the heat of combustion test, larger combustion flame area and faster combustion speed (the time reduced by 20.0 %) in the air, compared with that of raw-Al/PTFE. In conclusion, this method is simple and effective to enhance the energy release of aluminium powder, which is of great significance for improving the energy of weapons and equipment.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Dongyang Qiu,Xianfeng Chen,Lijuan Liu,Chuyuan Huang,Xiangyu Lv,Xuxu Sun
To ensure the safety of the Al powder/H 2 hybrid system in industrial production, the variation law of H 2 explosion parameters under the environment of Al powder with a concentration of 0–150 g/m 3 was investigated in the confined container, and feasible hybrid explosion suppression approaches were explored. The results show that with the increasing concentration of Al powder , the explosion intensity of the hybrid systems exhibited an enhancing trend in all cases. The explosion hazard of the hybrid system was most severe when the concentration of H 2 reached stoichiometry . At 30 % H 2 and 150 g/m 3 of Al powder, the maximum explosion pressure ( P max ) of the hybrid system was almost 2.4 times compared to the pure 30 % H 2 explosion. CO 2 -driven silica/sodium phytate (SiO 2 /PA-Na) suppressed explosions more effectively than N 2 -driven SiO 2 /PA-Na. As the mass fraction of SiO 2 /PA-Na was increased to 50 wt%, the CO 2 -driven solid inhibitors decreased the P max and deflagration index ( K st ) of the hybrid system by 60.9 % and 90.1 %, respectively, and the delay of the time to peak explosion pressure ( T p ) was elevated to 306.4 %. Furthermore, it was revealed that the multi-component inhibitors suppressed the Al powder/H 2 hybrid explosion mainly through comprehensive effects such as adsorption of heat , dilution of oxygen, disruption of chain reactions, and isolation reactants. This study contributes to the enrichment of experimental evidence of Al powder/H 2 hybrid explosion and the precise development of efficient explosion prevention technology.
研究领域:
工业安全
·
化学工程
·
爆炸科学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xiandie Zhang,Haozhe Li,Xuxu Cui,Weiduo Fei,Xinwen Ma,Jiaming Liu,Pingyun Li,Xiaode Guo,Xiang Zhou
Aluminium (Al) powder is the most common solid fuel component in metastable intermolecular composites (MICs). It is used in the field of propellants to provide energy for the flight of rockets and missiles. However, the passivation layer overlaying its surface hinders its energy release. Using fluorine (F)-containing oxidisers may etch the passivation layer, enabling Al to achieve a more direct redox process and improving its energy-release capacity. Herein, NH 4 CuF 3 , which has nano-network structure, was synthesised through the solvo-thermal method, and n-Al was filled into the nano-pore channels using a simple ultrasonic mixing method to form a new n-Al/NH 4 CuF 3 MICs with excellent dispersion and interfacial contact. The thermal decomposition process of NH 4 CuF 3 was investigated, and the results showed that NH 4 CuF 3 could release hydrogen fluoride (HF) and ammonia (NH 3 ) gaseous products. The passivation layer on the surface of the Al powder was etched by HF, and the abundance of gaseous products during the reaction of n-Al/NH 4 CuF 3 Extended the combustion region. This can enhance air capture in the reaction system, minimise reaction sintering and aid in performing external work. Furthermore, n-Al/NH 4 CuF 3 exhibits a lower onset reaction temperature, shorter ignition delay time and greater external work ability than n-Al/CuF 2 and n-Al/CuO.
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
·
2020
·
IF 4.57
De-Yun Tang,Zhi-Min Fan,Guangcheng Yang,Yinglei Wang,Pei-Jin Liu,Qi-Long Yan
Aluminum (Al) has been widely used in solid composite propellants (SCPs) to increase the specific impulse. However, Al always subjects to coalescence , sintering to large agglomerations during combustion of SCPs resulting in larger two-phase flow losses. Herein, core-shell μ-Al@M(IO 3 ) x composites have designed and synthesized as a replacement for micron-sized Al (μ-Al) in the Al/AP/RDX/HTPB propellant with tunable combustion behavior. The results show the thermal reactivity and heat releases of SCP are largely enhanced by using these novel metal-based composites. With the inclusion of μ-Al@EGCG@Fe(IO 3 ) 3 (EGCG: Epigallocatechin gallate), the major exothermic peak is reduced by 29.1 °C compared to the reference propellant with a heat release increase up to 5475 J g −1 , exceeding that of the reference sample (86 J g −1 higher). The burn rates are increased with the inclusion of μ-Al@(MIO 3 ) x , while the pressure exponent is higher. The SCP-1 (0.3), SCP-2 (0.18) and SCP-4 (0.25) that have relatively low pressure exponent and high burn rates are good candidates for future applications. The major condensed combustion products (CCPs) of these SCPs are Al 2 O 3 , Al 2.81 O 3.56 N 0.44 , Al 4 C 3 , Al 2 OC, AlN and C 7 H 18 ClN. The agglomeration can be reduced with a minor inclusion of μ-Al@M(IO 3 ) x due to the enhanced interfacial reactions, and the average CCP sizes (0.5 μm for SCP-1 and SCP-4) are even smaller than that of initial μ-Al (1.2 μm).
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 10
·5725-5732
·
IF 3.108
Baozhong Zhu,Fan Li,Yunlan Sun,Qichang Wang,Yuxin Wu,Zicheng Zhu
To develop the combustion characteristics of aluminum powder in steam, the ignition and combustion process of aluminum powder with different additives (KBH4, ammonium perchlorate (AP) and NaCl) addition at different levels were studied using a transparent pipe furnace. The temperature variation of these samples was measured using a thermocouple, and a high-speed camera was used to record combustion phenomenon. The solid combustion products of these samples with good characteristics were collected to analyze the microstructure and component. The results indicate that the ignition temperature of aluminum powder is decreased by adding these additives or increasing the content of the additive, whereas the maximum combustion temperature is different. When adding 3 wt% KBH4, the maximum combustion temperature reaches up to 1404 °C, which is higher than that of the original aluminum powder. However, upon addition of AP or NaCl the maximum combustion temperature decreases. Simultaneously, the combustion flame of aluminum powder with addition of KBH4 or AP is comparatively intense and bright, whereas the addition of NaCl reduces combustion intensity. The different influence mechanisms of additives on the ignition and combustion of aluminum powder are believed to be responsible for the experimental results.
研究领域:
材料科学
·
燃烧学
·
化学工程
✓ 已验证
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2019
·Vol. 45
·期 3
·493-502
·
IF 1.634
Zhicheng He,Zhixun Xia,Jianxin Hu,Likun Ma,Yang Li
To study the mechanical properties of lithium-perchlorate/polyvinyl alcohol-based aluminized electrically controlled solid propellant (LP/PVA-Al-ECSP), the effects of Al particle size, grading, and content on the mechanical properties of the propellant at various temperatures were investigated. The uniaxial tensile experiments were conducted over the temperature range from −40 °C to +50 °C using universal testing machine with a crosshead speed of 100 mm min −1 . A scanning electron microscope (SEM) was employed to observe the fracture surface morphologies of the specimens. The results indicate that Al powder and temperature greatly affects the mechanical properties of the composite propellant. From experiments in which the size and the fine-to-coarse ratio of Al were changed at constant solid loading, the tensile strength and initial modulus of the propellant are improved with the increase of Al particle size and coarse-to-fine ratio at 25 °C. The increase in Al content improves the tensile strength and initial modulus of the propellant, whereas reduces the elongation. The results of experiments in which the temperature changed indicate that the tensile strength and initial modulus of the propellant are improved at low temperatures, whereas the mechanical properties of the propellants deteriorate at high temperatures. The elongation of the propellants is greatly reduced at low temperatures. The stress−strain curve of ECSP shows three regions at low temperatures and five regions at room temperature and high temperatures. The LP/PVA-Al-ECSP has poor tensile strength and initial modulus, whereas its elongation is extremely high at room temperature. The propellant with 5 μm Al to 65 μm Al ratio of 3/7 exhibits the best comprehensive mechanical properties.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Xiang Lv,Yi Gao,Yueshuai Cui,Chen Wang,Gangchui Zhang,Fang Wang,Peijin Liu,Wen Ao
The ignition and combustion properties of n -Al/CuO/kerosene nanofluid fuels are examined, with a focus on the formulation effects of the n -Al/CuO nano-thermite. The DSC data shows the addition of CuO facilitates the exothermic process of n -Al particles, which then promote the n -Al/CuO/kerosene droplets to evaporate. There are two exothermic peaks on the DSC curve of n -Al/CuO (5 %) at 249.3 ℃ and 463.8 ℃, respectively. The burning of n -Al/CuO/kerosene droplets consists of four stages: ignition, d 2 -law combustion, vapor flame extinguishment, and agglomerate burning. During the agglomerate burning stage, n -Al/CuO (5 %)/kerosene shows the minimum ignition delay at 0.057 s and the highest emission spectral intensity. Droplet combustion conforms well to the d 2 -law, and the maximum combustion rate is found for n -Al/CuO (20 %)/kerosene, at 1.287 mm 2 s −1 . The particle size of combustion residues is uniform, and the overall appearance smoothens as the CuO content increases. A new nanofluid fuel with better ignition and combustion properties than traditional nanofluid fuels is proposed.
研究领域:
能源科学
·
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Manufacturing Processes
·
2021
·
IF 5.01
He Li,Yongsheng Liu,Yansong Liu,Qingfeng Zeng,Jingjing Liang
Stereolithography based-3D printing technology requires ceramic slurries with high solid content and low viscosity to prevent the formation of cracks, holes, warping, and other defects in sintered ceramic parts. In this study, several approaches based on optimization of alumina powder and coupling agent were explored to improve the solid content of ceramic slurries. It was shown that slurries containing γ-Al 2 O 3 reached solid content of only 22.5 wt% and viscosity of 15,199 mPa·s. By comparison, slurries composed of α-Al 2 O 3 reached higher solid content of 75 wt% and viscosity of 12,780 mPa·s. Three types of coupling agents, namely (3-Aminopropyl) triethoxysilane, (Aminoethylamino) propyldimethoxymethylsilane and 3-(Trimethoxysilyl) propyl methacrylate (abbreviated as E, F and G, respectively) were used to reduce the viscosity of the slurries. The addition of 10 wt% G led to slurry solid content reaching 82 wt% and viscosity of 860 m·Pas. The significant decrease in viscosity was mainly attributed to the presence of bifunctional hydrolyzable groups in G, which could well attach to alumina. On the other hand, the presence of organo-functional groups might also well attach to the photosensitive resin. The ceramics prepared with γ-Al 2 O 3 exhibited numerous pores in both intraparticle and intergranular while those obtained with α-Al 2 O 3 showed pores in only intergranular. The porous structure in γ-Al 2 O 3 occupied large space, leading to low solid content. Ceramics prepared with 75 wt% solid content possessed flexural strength of 29.3 MPa, bulk density of 2.3 g/cm 3 and open porosity of 39.8 %. By comparison, ceramics prepared with 82 % solid content showed flexural strength of 45.0 MPa. In sum, these findings look promising for future preparation of high-solid content 3D printed ceramic slurries for complex ceramics, such as ceramic cores.
研究领域:
材料科学
·
3D打印技术
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Longfei Yun,Yanan Wang,Baozhong Zhu,Yunlan Sun
Aluminum (Al) powder is easy to agglomerate in the combustion process , thereby inhibiting its continuous combustion, which results in the reduction of combustion intensity and combustion efficiency directly. Polyacrylamide (PAM), as a high molecular weight polymer , has the potentiality to react with Al via many aromatic compounds produced from its cracking. In this study, a solvent/non-solvent method was used to successfully coat micron-sized Al particles with PAM to form the PAM@μAl, aiming to improve their ignition and combustion properties . The results show that PAM and μAl interact in the PAM@μAl samples, and PAM inhibits the generation of oxide layer on the Al surface during the combustion process, while the presence of Al affects the thermal behavior of PAM. The combustion process of the PAM@μAl samples includes three stages: explosive combustion, transitional combustion, and stable combustion. Compared with the monolithic Al, the PAM@μAl samples have a shorter ignition delay and greater combustion intensity, and the oxide shell on the surface of Al particles is more easily broken, which is beneficial to the internal molten Al overflow. In addition, PAM can effectively inhibit the agglomeration behavior between Al particles during the combustion process. In particular, the best ignition and combustion performance of the PAM@μAl samples appears when the mass percentage of PAM is 7 wt.%.
研究领域:
材料科学
·
燃烧与热能工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
S.H.E.N. Ya-Qiang,L.I. Dong-Yun,X.U. Yang,G.E. Hong-Liang,X.U. Qiang,Y.A.N.G. Hui
High purity ultrafine alumina powders with different crystalline phases and morphologies were prepared by solid-phase sintering method. The influence mechanism of halides on the particle characteristics of alumina powders was studied. The results showed that NH 4 F additives induced the conversion of metastable alumina to α-alumina at high temperature, lowered the phase transformation temperature of α-alumina by about 300 °C, increased the α-alumina conversion rate by about 11.6%, reduced the sodium oxide content by about 72.3 wt%, and caused the alumina crystals to grow in a platelet shape manner. By comparison, NH 4 Cl additives had less effect on the transition temperature of α-alumina and the impurity content, and the particle morphology of alumina was a mixture of vermicular and platelet shapes. This study revealed the influence mechanism of two kinds of halides on the phase conversion, morphology evolution, and sodium removal of alumina powders from sintering mechanism and the theories of crystal structure, adsorption on the solid surface, and electronegativity of atoms.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）