VACUUM
·
2020
·
IF 2.906
Jiaxing Song,Tao Guo,Miao Yao,Jialin Chen,Wen Ding,Fengli Bei,Yiming Mao,Zhongshen Yu,Junyi Huang,Xiaonan Zhang,Qin Yin,Shuo Wang
The performance of energetic materials is mainly reflected in two aspects, thermal performance and combustion performance. To figure out the differences in reaction performance, in this paper, thermal and combustion properties of Al/CuO, Al/Fe 2 O 3 and Al/MnO 2 nanothermites were studied respectively by thermal analysis and fast heating wire experiments. According to the thermal analysis, the exothermic peak temperature points of Al/MnO 2 , Al/CuO, Al/Fe 2 O 3 nanothermites were 552.1 °C, 563.1 °C and 565.3 °C, respectively, while the sequence of activation energy calculated from low to high was Al/Fe 2 O 3 , Al/CuO, Al/MnO 2 nanothermites. By the way, the values of Al/CuO and Al/Fe 2 O 3 nanothermites showed little difference in temperature and activation energy. The ignition energy characterized by direct current had little difference among them, and the sequence from low to high was Al/MnO 2 , Al/Fe 2 O 3 , Al/CuO nanothermites, corresponding to 1.169 A, 1.214 A and 1.221 A, respectively. As for burning rate, Al/CuO burnt the fastest clearly while the Al/Fe 2 O 3 burnt the longest. In terms of combustion performance, Al/CuO and Al/MnO 2 were basically the same, with little splash of sparks, and the concentrations of combustion energy were better. The combustion phenomenon of Al/Fe 2 O 3 nanothermite was quite unique with a large number of scattered sparks and poor energy concentration. Finally, the intrinsic reasons for above different phenomena of these three nanothermites were analyzed and discussed.
研究领域:
材料科学
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化学工程
·
燃烧科学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2021
·Vol. 28
·期 11
·1868-1874
·
IF 2.232
Xiong Shan-xia,Kuang Jian-lei,Zheng Qian-fang,Xiao Ting,Liu Wen-xiu,Wang Qi,Jiang Peng,Cao Wen-bin
Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human health. In this study, inorganic aluminosilicate coatings prepared by combining metakaolin, silica fume, NaOH, and H 2 O were applied to the surfaces of wood-based panels to obstruct formaldehyde release. The Si/Al, Na/Al, and H 2 O/Na 2 O molar ratios of the coatings were regulated to investigate their effects on the structure and formaldehyde-resistant barrier properties of coatings. Results showed that the cracks in the coatings gradually disappeared and the formaldehyde resistance rates of the barrier increased as the Si/Al molar ratio was increased from 1.6 to 2.2. This value also increased as the Na/Al molar ratio was increased from 0.9 to 1.2 because of the improvement of the degree of polymerization. As the H 2 O/Na 2 O molar ratio was increased from 12 to 15, the thickness of the dry film decreased gradually and led to the reduction in the formaldehyde resistance rate. When the Si/Al, Na/Al, and H 2 O/Na 2 O molar ratios were 2.2, 1.2, and 12, respectively, the inorganic aluminosilicate coating showed good performance as a formaldehyde-resistant barrier and its formaldehyde resistance rate could reach up to 83.2%.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Hongyu Wang,Tao Wang,Gonghao Li,Bo Wu,Ruijun Gao
Balancing increased recoverable strain with high phase transformation temperature is crucial for Cu-Al-Mn SMAs to cost-effectively overcome the service temperature limitation (<100°C) of NiTi-based SMAs. This study fabricated four types of Cu-12.5Al-3Mn SMAs modified with nano-Al₂O₃ p (0, 0.5, 1.0, and 1.5 wt%) using wire arc additive manufacturing (WAAM) with cored wires. It investigated the effects of nano-Al₂O₃ p on shape memory properties, exploring mechanisms via microstructural, phase, and hardness analysis. Results show that adding an appropriate amount of nano-Al₂O₃ p significantly enhances memory performance while maintaining high martensite transformation temperatures. The 0.5 wt% nano-Al₂O₃ p modified alloy exhibited optimal properties: a shape recovery rate of 87.77 % (13.8 % higher than the base alloy) and a recoverable strain of 7.02 % (>40 % higher than the commonly reported 5 %) under 8 % bending pre-strain. Its Ms temperature remained above 100°C (As, Af, Mf were largely unchanged), and full recovery time was halved compared to the unmodified alloy. The enhancement is attributed to nano-Al₂O₃ p strengthening the parent phase and improving thermoelastic martensite order via pinning. Their high stability under WAAM's high-energy heat source minimizes impact on alloy composition, while dispersed particles create lattice distortion and stress fields, reducing the energy barrier for martensitic transformation.
研究领域:
材料科学
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冶金学
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纳米技术
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机械工程
✓ 已验证
产品关联
DOI
高影响因子
Energetic Materials Frontiers
·
2022
·
IF 0
Hua Fang,Jin-qiang Zhou,Peng Deng,Peng-fei Zhu,Xue-yong Guo
To understand the thermal decomposition and combustion characteristics of HMX/aluminum (Al) composites, this study prepared the HMX/Al composites with different Al contents and carried out the thermal decomposition and combustion performance tests of these composites. The thermal analysis results showed that the activation energy of the HMX/Al composites increased from 483.94 kJ·mol −1 to 541.60 kJ·mol −1 when the Al content increased from 0 to 30 wt%. However, the change in the Al content had little effect on the heat flow of the HMX/Al composites. The combustion results showed that the calorific value of HMX/Al-30 composite reached 16,860 J·g −1 . The flame height and burning intensity gradually increased with an increase in the Al content, and the burning duration of HMX/Al-10, HMX/Al-20, and HMX/Al-30 gradually decreased by 0.21, 0.57 ms and 0.91 ms, respectively. The results showed that Al powder as metal fuel can control the combustion reactions and energy output of HMX-based explosives.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Hui Huang,Xiaowu Chen,Junmin Zhang,Jinshan Yang,Xiangyu Zhang,Yanmei Kan,Yudong Xue,Hao Qin,Xiao You,Shaoming Dong
As the promising candidates for hot section components used in gas turbines , SiC f /SiC composites suffer severe gas steam/melt corrosion, so their long-term stability depends on the surficial environmental barrier coatings . Here, we provide an alternative method to construct the protective structure by thermal diffusion . Firstly, Y-Al diffusants is diffused into the SiC substrate, forming a Y-Al diffusion layer . Then the diffusion layer can transform to a corrosion-resistant Y(Al)Si x O y layer after oxidative treatment. The compositions and morphologies of the as-received diffusion layer and the Y(Al)Si x O y layer were contrasted. Results show that a Y(Al)Si x O y protective layer, which thickens with the extension of oxidative treatment time and the increase of Y/Al ratio, can be formed on the SiC surface. Concentration gradient caused by preferential oxidation of Y-Al prompts the Y-Al diffusing towards surface. Meanwhile, the oxidation of Y-Al makes the Y(Al)Si x O y layer denser and thicker, and finally form the Y(Al)Si x O y protective layer.
研究领域:
材料科学
·
表面工程学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Pan Liu,Xiangyu Li,Long Cheng,Xuqiang Zhu,Yanchun Li,Dongming Song
A new type of nanothermite composed of n-Al (metal fuel) and FeF 3 (oxidizer) was investigated in this paper. The thermal behavior and combustion properties of the n-Al/FeF 3 nanothermite were compared with that of n-Al/Fe 2 O 3 nanothermite by TG/DSC-MS, XRD, SEM and high-speed camera. The results showed that the decomposition of FeF 3 begins at 300 °C and releases free F ions. The F ions react with Al 2 O 3 shell covered on the surface of aluminum. The start and exothermic peak temperatures of the major reaction of n-Al/FeF 3 are at 415 °C and 520 °C respectively, which are 95 °C and 34 °C lower than those of n-Al/Fe 2 O 3 . Furthermore, the FeF 3 will be reduced to Fe completely at 700 °C. However, the Fe 2 O 3 could only be converted to Fe 3 O 4 . It demonstrates that the reaction of n-Al/FeF 3 is completely, but only a part of n-Al/Fe 2 O 3 reacts at 700 °C. The n-Al/FeF 3 has larger, brighter flame and shorter burning time than n-Al/Fe 2 O 3 in open air.
研究领域:
材料科学
·
燃烧化学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION SCIENCE AND TECHNOLOGY
·
2025
·
IF 1.5
Baichen Chen,Yi Wang,Jianchen He,Xiaolan Song,Chongwei An
This article uses a combination of experimental and simulation methods for mutual verification to explore the possibility of nano aluminum thermite damaging chips and disrupting circuit systems. In terms of experiments, Fe2O3/SiO2/Al and SnO2/SiO2/Al aluminum thermites were prepared by physically mixing micro Al powder, nano SiO2, and nano metal oxide powder in a certain proportion. The binder was added and pressed into a charge column for ignition testing. The prepared aluminum thermite was characterized and its performance was tested using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy(XPS), and constant pressure combustion experiments.In terms of molecular dynamics simulation, Materials Studio software was used to investigate the interaction relationships between atoms in the aluminum thermite. The reaction process and properties of the aluminum thermite under adiabatic conditions at different initial temperatures were explored from the perspectives of potential energy, radial distribution function, mean square displacement, and self diffusion coefficient. The simulation results were compared with experimental reaction phenomena. The results show that the aluminum thermite prepared by physical method is uniformly mixed, various materials are fully adhered, well dispersed, and there is no agglomeration phenomenon. In terms of combustion performance, the overall performance of Fe2O3/SiO2/Al thermite is better than that of SnO2/SiO2/Al thermite, with higher combustion efficiency, higher reaction temperature, and the ability to maintain high temperature for a longer period of time. The combustion of Fe2O3/SiO2/Al aluminum thermite is more complete, and the reaction generates more elemental Si, which plays a positive role in the damage of chips. In terms of molecular dynamics simulation, the aluminum thermal reaction of Fe2O3/SiO2/Al at different initial temperatures is more stable, with a faster energy release rate and a higher total energy content than SnO2/SiO2/Al. The aluminum thermal reaction generates oxides of elemental Fe/Sn, Si, and Al. Overall, the diffusion coefficients of both aluminum thermites increase with the increase of initial temperature, and the intensity of the reaction also increases with the increase of initial temperature. Temperature has an accelerating effect on their diffusion, and SnO2/SiO2/Al has stronger diffusion ability than Fe2O3/SiO2/Al. The Fe2O3/SiO2/Al aluminum thermite has a better damage effect on chips, and the simulation and experimental results are consistent.
研究领域:
材料科学
·
计算化学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Yang Xu,Handong Jiao,Mingyong Wang,Shuqiang Jiao
Vanadium-aluminum (V-Al) alloy, the master alloy for the well-known Ti-6Al-4V alloy, is mainly produced via aluminothermic reduction process of V 2 O 5 over the past decades. However, the reaction rate is too fast and it is difficult to control the product quality. Moreover, the utilization of aluminum is very low due to the production of Al 2 O 3 . In this work, a new method is proposed to prepare V-Al alloys by molten salt electrolysis of soluble NaVO 3 on a liquid aluminum (Al) cathode in molten NaCl-KCl melt. The results show that VO 3 − ions can be reduced to metallic V-Al alloys on the liquid Al cathode during electrolysis process. Furthermore, thermodynamic and electrochemical analysis indicate that the reduction of VO 3 − ions on the liquid Al cathode results from the combined effect of electroreduction and aluminothermic reduction. In this process, the liquid Al can not only reduce VO 3 − ions to V, but also to combine with vanadium to form V-Al alloys. However, unlike the traditional aluminothermic reduction process, alumina produced due to the aluminothermic reduction will be in-situ electro-reduced to aluminum, which will be helpful to increase the utilization of aluminum. As a result, when the electrolysis voltage is enough large, VO 3 − ions will be completely reduced. Al 3 V alloy without alumina can be obtained.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Yongzhao Zhang,Xuzheng Chen,Yunlei Zhou,Tao Feng,Luping Lyu,Zhenya Zhu,Yifan Liu
The efficient transformation of glucose into 5-hydroxymethylfurfural (5-HMF) is crucial for sustainable bio-refinery processes, but achieving high production efficiency remains challenging. In this study, we presented the preparation of Al-containing metal-organic frameworks (MOFs), specifically MIL-53(Al), MIL-53(Al)-NO2, and MIL-53(Al)-NH2, using different ligands as catalysts to enhance the production of 5-HMF from glucose. Comprehensive characterization provided valuable insights into the properties of the synthesized MOFs. The synthesized MOFs exhibited varied MIL-53(Al) states, morphologies, and thermal stabilities based on the different ligands employed, which in turn affected their catalytic performance. Among the Al-containing MOFs synthesized, MIL-53(Al)-NH2 demonstrated remarkable catalytic capabilities for the conversion of glucose to 5-HMF. This MOF achieved an impressive 5-HMF yield of 53% and a reaction selectivity of 54%. The catalytic efficiency was further enhanced by leveraging the synergistic effect of MIL-53(Al)-NH2 in combination with Amberlyst-36, resulting in a 5-HMF yield of 59% and a reaction selectivity of 60%.
研究领域:
化学工程
·
催化
·
材料科学
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2012
·
IF 2.234
Wenting Xue,Peng Zhang,Yong Zhao,Pei Liu
Salophen Al complex functionalized graphene (SCFG) nanocomposite was synthesized by simple coordination of phenol functionalized graphene (PFG) and as-prepared salophen Al complex. This process is facile, convenient and high efficient. We also investigated the structure, optical properties and electrochemical properties of the obtained SCFG composites. The results showed that salophen Al conjugated and incorporated onto the graphene sheet surface and the composites maintained the micro-structure of graphene sheets without agglomeration. The photoluminescence of salophen Al was completely quenched by graphene, due to the charge transfer between the salophen Al and the graphene nanosheets. Moreover, a significant electrochemical signal emerged on the SCFG modified electrodes compared with those of the graphene sheets or salophen Al complex. Owing to preliminary results of the excellent electrochemical property, SCFG nanocomposite is a promising electrochemical redox probe material.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Yanghuan Huang,Haocheng Zhang,Lou Gao,Tianlan Yan,Yueer Yan,Yahong Zhang,Yi Tang
A series of Zr–Al-MWW zeolites with different Zr state and layer-stacking structure are successfully synthesized via direct grafting zirconocene dichloride onto the external silanols of three kinds of MWW zeolites, i.e. MCM-22 with multilayered structure, ITQ-2 (through layer delaminated route) and OL-MWW (by direct hydrothermal synthesis) with oligolayered structure. The structure, porosity and state of grafted Zr species are distinctly different among the three Zr–Al-MWW zeolites. Zr-OL-MWW possesses the highest content of single Zr atoms with an ideal micro-meso-macro pore system, while Zr-MCM-22 and Zr-ITQ-2 contain two kinds of Zr species (ZrO 2 clusters and single Zr atoms) coexisting in various proportions. The high dispersion of single Zr atoms on OL-MWW can be assigned to the large amount of external silanols of OL-MWW. The as-prepared three bi-functional Zr–Al-MWW zeolites are used for the cascade Meerwein-Ponndorf-Verley (MPV) reduction and etherification (ETH) reaction. Among them, Zr-OL-MWW shows dramatically higher conversion of cinnamaldehyde and yield of 1-cinnamyl 2-propyl ether than Zr-MCM-22 and Zr-ITQ-2, owing to the higher catalytic activity of Lewis acid centers from single Zr atoms, as well as more integrated framework Al sites as Brønsted acid centers with good accessibility. This study offers a simple and efficient strategy to construct Lewis-Brønsted acidic zeolites with exposed heteroatom sites and integrated framework structure, which will provide especial potential in the catalytic conversion of macromolecules.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2022
·
IF 6.959
Yanxue Guan,Juan Qin,Xinyue Guo,Zongjia Li,Haoran Guo,Miaomiao Zhang,Bailin Zhang,Jilin Tang
Nickel-aluminum layered double hydroxides (Ni-Al LDHs) are widely used in energy storage and conversion devices, and the impact of the Ni/Al molar ratio on the structural evolution and kinetic process is of great significance for improving reaction kinetics and efficiency. In this paper, the morphological evolutions and nanomechanical property changes of Ni-Al-n LDH (n is the Ni/Al molar ratio) nanosheets during potential cycling were explored by in situ electrochemical atomic force microscopy. The conversion of Ni2+ into Ni3+ and the amphoteric properties of Al3+ during potential cycling resulted in the dissolution of Ni-Al-n LDH nanosheets. The dissolution rate of Ni-Al-2 LDH nanosheets was slower than those of Ni-Al-2.5 LDH and Ni-Al-3 LDH nanosheets. Meanwhile, the Young’s modulus value of the dissolved area was much larger than that of the undissolved area, and the dissolved area exhibited a harder property. It was attributed to the different microcrystalline structures of Ni-Al LDH nanosheets affected by the Ni/Al molar ratio and the rearrangement of Ni2+ and Al3+ during the reaction. The slow dissolution of Ni-Al-2 LDH nanosheets was beneficial to improving the electrochemical performance, while the fast dissolution of Ni-Al-2.5 LDH and Ni-Al-3 LDH nanosheets was not conducive to the electrochemical performance. Understanding the effect of the Ni/Al molar ratio on the morphological evolutions and nanomechanical property changes of Ni-Al LDH nanosheets during potential cycling has important guiding significance for the subtle compositional modification and structural design of Ni-Al LDHs as an electrode material.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）