JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2019
·Vol. 137
·期 5
·1615-1620
·
IF 2.471
Yang Hongtao,Liu Yunfei,Huang Haitao,Zhao Yu,Song Kuanguang,Wang Haiyang,Xie Wuxi,Cheng Yi,Fan Xuezhong
In this study, an advanced electrospray process was successfully used to fabricate aluminum nanopowders (Al)/iron oxide nanopowders (Fe 2 O 3 )/hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)/nitrocellulose (NC) composite materials containing different RDX contents. Differential scanning calorimetric analysis indicates that the decomposition temperature of the RDX in the composition prepared by electrospray has a decrease of about 20 °C compared with the raw RDX. Combustion performances in air show that the RDX decreases combustion performance of nanothermites, and the combustion intensity decreases as the RDX content increases. Furthermore, the combustion cell test indicates that the maximum pressure peak has been greatly improved for the Al/Fe 2 O 3 /RDX/NC composites. The amount of released gas can be adjusted by the RDX content in Al/Fe 2 O 3 /RDX/NC composite.
研究领域:
材料科学
·
燃烧与爆炸
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2020
·
IF 3.784
Mikhailov Mikhail,Iurina Victoria,Neshchimenko Vitaly,Li Chundong
The effects of proton (E = 100 keV, F = 5 × 10 15 сm −2 ) exposure on the reflective spectra of Al 2 O 3 , CeO 2 , TiO 2 , Y 2 O 3 , ZrO 2 , ZnO micro- and nanopowders in wavelength range from 250 to 2500 nm have been investigated. It has been established that titanium dioxide nanopowders have higher radiation stability to protons exposure in comparison with the other white powders (TiO 2 , Y 2 O 3 , Al 2 O 3 , ZnO, ZrO 2 ) used as pigments for coatings. This effect is caused by high specific surface area of the nanoparticle causing fast recombination processes of electrons and holes in various surface drains.
研究领域:
材料科学
·
核物理学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2011
·
IF 1.472
Xinghong Zhang,Yang Hou,Ping Hu,Wenbo Han,Junting Luo
The dispersion and co-dispersion behavior of ZrB 2 and SiC nanopowders in ethanol solution was studied by sedimentation test, particle size measurement and transmission electron microscope (TEM) analysis. The dispersion behavior of ZrB 2 and SiC nanopowders in ethanol solution was strongly dependent on the pH values, types and amounts of dispersant. PEI was found to be effective for the dispersion of both ZrB 2 and SiC nanopowders in ethanol solution. With the addition of PEI, the isoelectric points of ZrB 2 and SiC nanopowders in ethanol solution were at pH 10 and pH 9.5, and shift to pH 13 and pH 12.3, respectively. The stability of ZrB 2 suspension increased with the dispersant content increasing until reached 0.7 wt% and well-dispersed SiC slurry can be obtained with more than 2.5 wt% PEI. The suitable pH value for the dispersion of ZrB 2 and SiC nanopowders should be lower than 12 and 10, respectively. The well co-dispersed ZrB 2 and SiC nanocomposite powders can be achieved by using 1 wt% or more PEI below pH 10.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2016
·
IF 2.188
Siyuan CHEN,Jintai FAN,Liangjie PAN,Benxue JIANG,Xiaojian MAO,Rihong LI,Xinqiang YUAN,Xiongwei JIANG,Long ZHANG
Yb:Lu 3 Al 5 O 12 (Yb:LuAG) nano powders were synthesized with the co-precipitation method from cation (Lu 3+ , Yb 3+ , Al 3+ ) solution of different concentrations using NH 4 HCO 3 as the precipitant. The influence of cation concentration on the morphology and purity of the calcined powders was studied. Contrary to the conventional suggestion that recommends thin solution to obtain loosely agglomerated nano powders, results showed that thin cation (Lu+Yb+Al) concentration ≤0.08 mol/L led to formation of Al 2 O 3 and LuAP impurities in the obtained nano powders. By means of Tg/(DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), the cause was revealed to be re-dissolution of Lu at high pH value that resulted from the decomposition of NH 4 HCO 3 . (Lu+Yb+Al) concentration of ∼0.24 mol/L was recommended to achieve pure Yb:LuAG nano powders. Transparent Yb:LuAG ceramics were fabricated with the prepared Yb:LuAG nano powders. The transmittance around 800 nm was 77.5%.
研究领域:
材料科学
·
光学材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Jiang Tan,Yuchang Su,Hongbo Tang,Te Hu,Qiushan Yu,Rabigul Tursun,Xiangyu Zhang
10Sc1CeSZ (10 mol% Sc 2 O 3 –1 mol% CeO 2 –89 mol% ZrO 2 ) nanopowders were prepared by hydrothermal and calcinations . The calcined powders were uniaxially compacted into pellets and sintered at 1400 °C for 2 h. The calcined powders and sintered pellets were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared transmission spectroscopy (FTIR) and impedance spectroscopy . The powders calcined at 800 °C for 2 h (and below 800 °C) was beneficial to pellets densification. After the powders were calcined at 800 °C for 2 h, the sintered pellets showed relative density of 97.5%, and its conductivity was 0.108 S cm −1 at 800 °C. The powders calcined at 800 °C for 24 h showed the better conductivity of 0.131 S cm −1 at 800 °C. The microstructure, bulk density and electrical properties of the sintered pellets can be tuned using different calcined parameters.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2012
·
IF 0
Yang Hou,Ping Hu,Wen Bo Han
The dispersion of SiC nanopowders in ethanol solution was studied by sedimentation test, particle size measurement and TEM analysis. The dispersion behavior of SiC nanopowders in ethanol solution was strongly dependent on the pH values, types and amounts of dispersant. PEI was found to be effective for the dispersion of SiC nanopowders in ethanol solution. With the addition of PEI, the isoelectric points of SiC nanopowders in ethanol solution were at pH 9.5, and shift to pH 12.3. The stability of SiC suspension increased with the dispersant content increasing until reached 2.5 wt% PEI. The suitable pH value for the dispersion of SiC nanopowders should lower than 10.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 19
·1-8
·
IF 2.8
Yan Shuai,Hu Wencai,Wang Sen,Liu Gaobin
In this paper, Sr-doped BaTiO 3 nanoparticles were synthesized via electrochemical method, leading to the successful preparation of Ba 0.67 Sr 0.33 TiO 3 (BST) powders. The phase composition and microstructure of the powders were characterized using X-ray diffraction small angle X-ray scattering, scanning electron microscopy (SEM), and transmission electron microscopy. The results show that the average grain size of the nanoparticles is in the range of 10–20 nm, and the particles with good crystallinity are obtained under the environment of 3 mol.L −1 NaOH concentration. Sintering at 1250 ℃ for 3 h yields nanoscale BST ceramics with a dense structure and an average grain size of about 300 nm. These fine-grained ceramic samples exhibit superior temperature stability compared to relatively coarser BST ceramics. Furthermore, due to their nanoscale grain size, extensive phase transitions result in a low dielectric constant as observed from the dielectric property data. This work presents a novel approach for preparing nanoscale powders and homogeneous ceramics applicable in various electronic applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2022
·Vol. 25
·期 5
·2200175
·
IF 4.122
Meiqin Zeng,Youtao Pan,Weifeng Liu,Jie Cui,Zhongchen Lu,Min Zhu
This work prepares nanocrystalline tungsten carbide (WC) powder using conventional ball milling or plasma milling (P-milling) to process tungsten trioxide (WO 3 )–carbon (C) mixtures, with subsequent carbothermal reduction. The aim is to assess the effects of a discharge plasma on the microstructure of these materials. The results indicates that WC powders with particle sizes of less than 100 nm could be fabricated through heating at a relatively low temperature of 1150 °C for 1 h under vacuum after P-milling. This process is found to allow a lower processing temperature and provided more complete carburization in comparison with conventional ball milling. P-milling is determined to produce more loosely adhering WO 3 nanoparticles and a higher surface area, resulting in more reactive sites and a larger contact area between WO 3 nanoparticles and C atoms. This technique simultaneously generates more oxygen vacancies and defects on the surfaces of the WO 3 and C, respectively, based on the use of a plasma discharge. It is evident that this new technology permits nanocrystalline WC to be readily obtained from WO 3 and C in a reduced time span and at a lower cost and greater efficiency. This technique could also be used to fabricate WC nanopowders on an industrial scale.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Penghui Chen,Qiang Liu,Yagang Feng,Xiaoying Li,Xiaopu Chen,Yumin Liu,Jiang Li
Y 0.16 Zr 0.84 O 1.92 transparent ceramics were successfully fabricated by air pre-sintering combined with HIP post-treatment from the nanopowder synthesized by the co-precipitation method. Fine and low-agglomerated Y 0.16 Zr 0.84 O 1.92 powder with the average particle size of 14.8 nm was obtained by calcining the precursor at 800 °C for 4 h. The influences of pre-sintering temperature on the microstructure and optical quality of Y 0.16 Zr 0.84 O 1.92 ceramics were investigated. It is found that the relative density of pre-sintered Y 0.16 Zr 0.84 O 1.92 ceramics increases from 82.1% to 96.1% and the average grain size increases from 0.6 μm to 6.0 μm with the pre-sintering temperature increasing from 1250 °C to 1500 °C. The Y 0.16 Zr 0.84 O 1.92 ceramic sample pre-sintered at 1300 °C for 2 h and HIP post-treated at 1800 °C for 3 h without sintering additives exhibits the best transparency. In-line transmittance of Y 0.16 Zr 0.84 O 1.92 ceramics with the thickness of 1.0 mm reaches 72.4% at 800 nm, which is near to the theoretical transmittance.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2017
·
IF 2.238
Weiwei Li,Haijun Huang,Bingchu Mei,Jinghong Song
In this paper, ytterbium doped strontium fluoride (Yb: SrF 2 ) nanoparticles were synthesized by direct precipitation method. High-speed centrifugation was used to separate high sintering activity of nanopowders from powders with hard aggregated and large size. Using powders at different parts of the centrifugal tube as starting powders, Yb: SrF 2 transparent ceramics was fabricated by hot pressed (HP) method for the first time. Effects of morphology and particle size on the sinterability of Yb: SrF 2 nanopowders were investigated. The transmittance reached 77% at the wavelength of 1200 nm and pores stilled remained in the ceramics. The spectroscopic and thermal properties of Yb: SrF 2 transparent ceramics were also investigated. This paper provides an effective way to obtain well dispersed and high sinterability nanoparticles for SrF 2 ceramics sintering.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2021
·Vol. 35
·期 6
·1098-1103
·
IF 0.957
Zhai Xiaoyu,Peng Xiang,Ma Yunqian,Liu Ting,Liu Jiaxiang
The effect of particle size on the density and resistivity of ITO green bodies and targets was systematically investigated. The experimental results show that the relative density of ITO green bodies decreases with the increase of ITO particle size. When the particle size is 10.7 nm, the relative density of ITO green bodies rises to the maximum value of 56.6%. The resistivity declines exponentially with the increase of particle size, which satisfies the exponential equation of R = exp(−41.823 × d). When the particle size is 41.6 nm, the resistivity reaches the minimum value of 0.8 Ω·cm. The relative density of ITO target decreases with the increase of particle size. Fine particles can increase the driving force of densification in initial stage. Electron mobility, caused by grain boundary scattering, will increase due to the increase of particle size or the decrease of grain boundary potential. When the particle size is 10.7 nm, the target with compact grain stacking and low porosity shows a maximum relative density of 99.25%, and the resistivity reaches the minimum value of 0.34×10 −3 Ω·cm.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Wenwen Zhao,Kuibao Zhang,Zongsheng He,Jiali Xue,Weiwei Li,Dayan Xie,Haibin Zhang
Highly transparent La 1.28 Yb 1.28 Zr 2 O 7.84 ceramic was prepared by vacuum sintering using nanosized raw powders, which were synthesized by a simple solution combustion method using rare earth nitrate as the raw materials. The as-burnt powders were calcined at 1200 ℃ and then ball-milled for 24 h with resultant particle size of about 60 nm. The two phases, cubic pyrochlore and defective fluorite, are uniformly distributed in the ceramic. La 1.28 Yb 1.28 Zr 2 O 7.84 transparent ceramic with the maximum in-line transmittance of 83.9% was successfully prepared at 1850 ℃ for 6 h in a vacuum furnace.
研究领域:
材料科学
·
无机化学
✓ 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）