COMBUSTION AND FLAME
·
2024
·
IF 5.8
Xueqin Liao,Jianzhong Liu,Zexu Li,Mengxia Sun
Aluminum (Al) particles are widely used in propellants, thermite and pyrotechnics. However, commonly used micro Al has drawbacks such as agglomeration, high ignition temperature and slow burning rate, making its energy potential not fully exploited in applications. Therefore, exploring pathways to enhance the combustion of Al particles has become the focus at present. Herein, L -malic acid (LMA) was used to corrode the surface of Al particles to obtain a sample (named LMAl) with an average specific surface area of 11.456 m 2 /g (corresponding to Al particles with a diameter of 194 nm). The particle size distribution of LMAl did not change significantly compared to pristine Al. The XPS results showed that a small amount of LMA and corrosion products remained on the surface of the LMAl particles. Thermal analysis tests showed that the thermal oxidation rate and efficiency of LMAl was dramatically higher than that of pristine Al. Compared with the pristine Al, the combustion characterization parameters of LMAl such as combustion intensity, ignition delay time, maximum combustion temperature, mass burning rate and combustion efficiency were all improved. This trend was maintained after blending the ammonium perchlorate (AP). The condensed combustion products (CCPs) of Al revealed a large number of agglomerates and unburned Al particles. While many broken particles and tentacle-like structures were found in the CCPs of LMAl. Overall, compared to Al, the combustion of LMAl is significantly enhanced. The thermal reaction and combustion behaviors of the two are quite different. This study provides new insights into improving the ignition and combustion of Al.
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2025
·
IF 12.1
Ting Liu,Cui Nie,Yao-feng Mao,Yu Zhang,Gang Li,Fu-de Nie,Jun Wang,Jie Chen
The combustion efficiency and reactivity of aluminum (Al) particles, as a crucial component in solid propellants, are constrained by the inert oxide layer aluminum oxide (Al 2 O 3 ). Polytetrafluoroethylene (PTFE) can remove the oxide layer, however, carbon deposition generated during the reaction process still limits the reaction efficiency of Al/PTFE fuel. Here, a litchi-like Al/PTFE fuel with the nano-PTFE islands distributed on the Al particles surface is successfully designed, based on localized activation and synergistic reaction strategies, to solve the Al 2 O 3 layer and carbon deposition. This unique PTFE-coated structure can achieve localized activation of Al by surface etching, creating reaction channels, and exposing the active Al. Such a channel network promotes the circulation of fluorine and oxygen, stimulating the synergistic reactions of Al-F and Al-O and energy output. Regulating the PTFE content can maximize the elimination of carbon deposition and achieve the full combustion reaction of Al/PTFE. The maximum flame area and pressure output of the litchi-like Al/PTFE fuel increased by 241.9%, 734.7%, 118.4%, and 265.2%, respectively, compared with traditional physical mixture and core-shell structure Al/PTFE fuels. The localized activation and synergistic effects of litchi-like structure effectively transform carbon waste into a valuable resource, introducing a novel approach for the propellants.
研究领域:
材料科学
·
燃烧与推进
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACTA ASTRONAUTICA
·
2024
·
IF 3.1
Huanhuan Gao,Hui Liu,Peihui Xu,Jianzhong Liu
The potential of the Al-F reaction in suppressing agglomeration during propellant combustion and enhancing combustion performance is investigated by introducing fluorinated graphene as a fluorinated oxidizer. Comparative analyses of ignition combustion and agglomeration behaviors are conducted on novel composite powders and propellant samples modified with varying contents of fluorinated graphene using laser and hot wire ignition visualization systems. Characterizing parameters such as characteristic spectra, flame grayscale, ignition delay time, combustion duration, and burning rate are measured during combustion at different pressures. Additionally, agglomerated particles are collected via quenching techniques under 7 MPa pressure to explore the influence mechanism of fluorinated graphene on agglomeration near the burning surface, and a comprehensive influence mechanism is proposed. Results indicate that fluorinated graphene promotes ammonium perchlorate decomposition, accelerates oxidizing gas release, and enhances thermal conduction at the burning surface. The reaction between Al and F decreases the formation of intermediates (AlO and Al 2 O), while the interaction of F with Al and Al 2 O 3 effectively inhibits the clustering of Al particles, replacing conventional oxidation reactions and resulting in a unique micro-explosion jetting phenomenon. The introduction of 15 % fluorinated graphene concentrates most product particles around 10 μm, enhancing energy release during combustion. Overall, this composite powder containing fluorinated graphene effectively improves the combustion performance of aluminum-containing composite propellants, inhibiting Al particle agglomeration and potentially reducing specific impulse loss in solid rocket motors.
研究领域:
材料科学
·
燃烧学
·
推进剂工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Chao Wang,Xiangrui Zou,Shipan Yin,Junlong Wang,Hongyang Li,Ying Liu,Ningfei Wang,Baolu Shi
A novel ‘one-step’ in-situ electroless plating method capable of controlling phosphorus content was proposed for the fabrication of spherical core-shell energetic Al@Ni-P composites, aiming to prompt particle ignition by adding easy-to-ignite P element. In this experimental study, the preparation and characterization of Al@Ni-P composites, as well as the effect of coating an alloy shell on the Al particle surface were mainly addressed. The morphology and chemical composition heterogeneity demonstrated that the Al@Ni-P composites possessed comparatively dense double-shell structure. Thermal analysis showed that these composites could accelerate the rate of energy release by decreasing the apparent activation energy ( E a ) for particles oxidation. Laser ignition experiments were then conducted to examine the influence of Ni-P alloy on breaking through the barrier of ceramic phase Al 2 O 3 shell to improve the ignition and combustion performances. Moreover, the composites with surface P of 12.68 at.% exhibited extremely shorter laser ignition delay time of 86 ms under 1 atm O 2 atmosphere, reducing by 65.46% compared with that of raw Al particle (249 ms); and the pressurization rate reached 88.08 kPa/s under 10 atm O 2 atmosphere, which is approximately 11 times that of raw Al particle (8.09 kPa/s). These drastic improvements were attributed to the synergistic effects of double-shell structure and intermetallic compound exothermic reaction, which enhanced mass and heat transfer. These results demonstrate that Al@Ni-P composites have a promising future in solid composite propellants, which exhibit shorter ignition delay time and more vigorous combustion than raw Al. This strategy is expected to provide a new method for the construction of complex core-shell structural materials in other research fields.
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
Acta Metallurgica Sinica-English Letters
·
2020
·Vol. 33
·期 5
·649-658
·
IF 2.09
Li Dong,Wang Chaoyu,Su Yishi,Zhang Di,Ouyang Qiubao
The inclination angle of the flake particle has a significant impact on the in-plane thermal conductivity of composites. The graphite flake/Al composites (50 vol%) with different inclination angles were fabricated via flake powder metallurgy, and the results show that with increasing the size of Al particle from 25.6 to 50.7 μm, the inclination angle of graphite flake decreases from 7.3° to 4.4°, while the in-plane thermal conductivity of composites increases from 473 to 555 Wm −1 K −1 . Based on the rules of mixture, an effective model was established to qualify and quantify the relation between the inclination angle and the in-plane thermal conductivity of the corresponding composites. This model can also be applied to other flake particle-reinforced composites.
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yage Xia,Wancheng Gu,Li Shao,Xuan Jiao,Yanzheng Ji,Weilin Deng,Xinquan Yu,Yuxin Zhang,Youfa Zhang
Superamphiphobic coatings maintain surfaces clean even facing severe oil contamination, which is crucial for ensuring the lifespan of materials in highly polluted environments. Achieving excellent wear resistance and flexibility individually on superamphiphobic surfaces is relatively simple, but simultaneously obtaining both properties is challenging and often requires compromises. In this study, we develop an innovative approach inspired by “overcoming firmness by gentleness” to create superamphiphobic composite coatings with flexibility and abrasion tolerance. This innovative strategy combines a soft polyurethane resin with rigid diatomite/aluminum hydroxide (core–shell) particles, resulting in a coating structure resembling karst topography. Depositing aluminum hydroxide enhances the reactivity and content of hydroxyl groups on diatomite particles, simultaneously improving the hardness and 1H,1H,2H,2H-Perfluorodecyltrichlorosilane (FDTS) grafting degree of the core–shell particles. Residual hydroxyl groups on the semi-fluorination core–shell particles chemically bond with the isocyanate groups in the waterborne polyurethane resin, leading to enhanced crosslinking density and improved wear resistance of the coating. The top coating of F-SiO 2 particles leads to a reduction in the surface energy of the core–shell coating. The obtained core–shell coating demonstrates excellent oil resistance even after 800 cycles of Taber abrasion under a load of 250 g and 1000 cycles of 360° bending, demonstrating remarkable wear resistance and flexibility simultaneously. This approach provides valuable insights for developing superamphiphobic composite coatings with flexibility and abrasion tolerance and opens new possibilities for their applications in flexible electronics and droplet manipulation.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
Defence Technology
·
2024
·
IF 5
Qihang Chen,Xiaolong Fu,Weitao Yang,Suhang Chen,Zhiming Guo,Rui Hu,Huijie Zhang,Lianpeng Cui,Xu Xia
3D printing technology enhances the combustion characteristics of hybrid rocket fuels by enabling complex geometries. However, improvements in regression rates and energy properties of monotonous 3D printed fuels have been limited. This study explores the impact of poly (vinylidene fluoride) and polydopamine-coated aluminum particles on the thermal and combustion properties of 3D printed hybrid rocket fuels. Physical self-assembly and anti-solvent methods were employed for constructing composite μAl particles. Characterization using SEM, XRD, XPS, FTIR, and μCT revealed a core-shell structure and homogeneous elemental distribution. Thermal analysis showed that PVDF coatings significantly increased the heat of combustion for aluminum particles, with maximum enhancement observed in μAl@PDA@PVDF (denoted as μAl@PF) at 6.20 kJ/g. Subsequently, 3D printed fuels with varying pure and composite μAl particle contents were prepared using 3D printing. Combustion tests indicated higher regression rates for Al@PF/Resin composites compared to pure resin, positively correlating with particle content. The fluorocarbon-alumina reaction during the combustion stage intensified Al particle combustion, reducing residue size. A comprehensive model based on experiments provides insights into the combustion process of PDA and PVDF-coated droplets. This study advances the design of 3D-printed hybrid rocket fuels, offering strategies to improve regression rates and energy release, crucial for enhancing solid fuel performance for hybrid propulsion.
研究领域:
材料科学
·
航空航天工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Energy Technology
·
2020
·Vol. 8
·期 5
·1901429
·
IF 3.404
Qingtong Wang,Jian Yang,Zhuyi Wang,Liyi Shi,Yin Zhao,Shuai Yuan
Herein, the polyethylene (PE) separators are coated by micro/nanoalumina particles. The alumina particles with different sizes play different roles. The microalumina mainly enhances the thermal stability of the polyolefin separator and provides large channels for lithium-ion diffusion. The nanoalumina particles are helpful in improving the lithium-ion transference number by increasing the contact interface area of electrolyte/alumina. The lithium-ion transference number of the separators with different coatings increases from 0.32 to 0.40, mainly due to the ratio of micro/nanoalumina particles. Meanwhile, ion conductivity increases from 0.30 to 0.40 mS cm −1 . As a result, the cycling stability of the lithium metal anode is greatly improved by the synergetic effect of microsized alumina particles and nanosized alumina particles.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2018
·
IF 4.92
Chen Pan,Kaichang Kou,Yu Zhang,Ziyu Li,Guanglei Wu
Due to the strong horizontal orientation tendency of hexagonal boron nitride (hBN) platelets, hBN/polymer composites generally exhibit high in-plane thermal conductivity while low through-plane thermal conductivity. In this work, hBN platelets and aluminum nitride (AlN) particles are used as hybrid fillers to improve the thermal conductivity of polytetrafluoroethylene (PTFE). AlN particles effectively disrupt the alignment of hBN platelets along the lateral direction during the compression processing, which can be proved by the results of SEM and XRD . At 30 vol% filler loading, a high through-plane thermal conductivity as 1.04 W/mK is achieved, which is 3.8 times that of neat PTFE. The significantly increased thermal conductivity is related not only to the synergetic effect of hybrid fillers, but also the reduced in-plane orientation degree of hBN. Hashin-Shtrikman model is also used to quantify the filler connectivity within polymer matrix . The result suggests that filler morphology and orientation influence the filler connectivity and both control the effective thermal conductivity of composites.
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
高影响因子
INTEGRATED FERROELECTRICS
·
2022
·
IF 0.836
Shaopeng Wu,Lei Zhou,Xiaolan Cai,Qianghua Shen,Yuanchao Cheng,Changjiang Yang
Cu-Al2O3 composite materials combining the good electrical of copper matrix and the high hardness of Al2O3 ceramic particles show great performance in electronics, electrical sliding contacts fields. However, the relationship of a dilemma between strength and ductility has become a limitation for the development of copper matrix composites. The previous works indicated that fine grain powders can improve interfacial bonding between the copper matrix and Al2O3 particles to further enhance strength while maintaining ductility. In the present work, the multiscale-alumina particles reinforced copper matrix composites were successfully fabricated by mixing high-energy ball milling and consolidation of hot-press sintering. SEM and TEM were used to observe the powder morphology and microstructure of Cu-Al2O3 composites. The results show that the reinforcing phase Al2O3 particles are uniformly dispersed in the copper matrix, which improves interfacial bonding between the copper matrix and Al2O3 particles. Especially, the micro Al2O3 particles play an important role in achieving an excellent tradeoff of strength and ductility in the Cu-Al2O3 composite. In addition, the microhardness of Cu-Al2O3 composites can be greatly improved by using the high-energy ball milling and hot-press sintering process. The research idea of this paper can provide a reference for other composite materials that need to improve mechanical properties.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
·
2021
·Vol. 219
·期 3
·2100625
·
IF 1.981
Han He,Yehua Jiang,Juanjian Ru,Yixin Hua
Compact and continuous Ni-coated zirconium oxide-toughened alumina (ZTA) particles (ZTA p @Ni) and CuNi-coated ZTA particles (ZTA p @CuNi) are prepared by electroless deposition. The thicknesses of the Ni and CuNi coatings are 6.84 and 21.35−43.10 μm, respectively. The ZTA p @Ni- and ZTA p @CuNi-reinforced high-chromium cast iron (HCCI) composites are fabricated by nonpressure cast-infiltration method. Results show that compact interfacial bonding is formed in S3′-ZTA p @CuNi/HCCI without any casting defect. The addition of Ni element can effectively improve the amount of (Cr,Fe) 7 C 3 and refine the grains in HCCI matrix, and Cu element can improve the strength and toughness of the matrix. The compression performance testing shows that the compressive strength and yield strength of S3′-ZTA p @CuNi/HCCI are up to 1128.03 and 1049.40 MPa, respectively. In addition, three-body abrasive testing demonstrates that the abrasive wear resistance of the S3′-ZTA p @CuNi/HCCI is optimal. This can be attributed to the compact combination between ZTA p @CuNi and HCCI matrix, which benefits the load transfer and the protection of ZTA particles to avoid brittle fracture and debonding. So, the appropriate additions of Cu and Ni elements, that is, the thickness and content control of CuNi coatings on ZTA surfaces, are very crucial for the performance improvement of composites.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
FIBERS AND POLYMERS
·
2015
·Vol. 15
·期 12
·2581-2590
·
IF 0.881
Yuan Zhengkai,Yu Jinhong,He Zihai,Wu Xinfeng,Rao Baolin,Lu Shaorong,Jiang Nan
A liquid crystalline epoxy (LCE) grafted AlN particles (LCE-g-AlN) were fabricated and then incorporated these into epoxy matrix to obtain the composites. The structure of LCE-g-AlN was characterized by Fourier-transform infrared (FT-IR), nuclear magnetic resonance (NMR), thermal gravimetric analyses (TGA), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC). The morphology and thermal properties of composites were systematically investigated. The morphology of the epoxy/LCE-g-AlN composites performed by scanning electron microscopy (SEM) indicated a homogeneous distribution of the LCE-g-AlN particles in epoxy. Moreover, the glass transition temperature (T g ), thermal stability, thermal conductivity and dynamic mechanical properties of composites showed a significant improvement due to the good miscibility and improvement of the interfacial interaction between LCE-g-AlN particles and epoxy matrix.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）