The solubility of layered perovskite-type organic-inorganic hybrids (CnH2n+1 NH3)2MCl4 (where M = Mn, Co, Cu, Zn;n = 2, 4, 6, 8, 10, 12) in seven kinds of solvent are obtained by atomic absorption spectrometry and tit...
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The solubility of layered perovskite-type organic-inorganic hybrids (CnH2n+1 NH3)2MCl4 (where M = Mn, Co, Cu, Zn;n = 2, 4, 6, 8, 10, 12) in seven kinds of solvent are obtained by atomic absorption spectrometry and titration method. The solvents are sherwood oil, cyclohexane, acetone, trichloromethane, DMF, methanol and water. The results show that the hybrids are prone to dissolve in polar solvent. This is attributed to the polarity of the hybrids. The hybrids disassembly dissolve when the interaction between the ammonium and the electron-donating group of the solvent is stronger than that between the organic and the inorganic parts in the hybrids. The series of M = Zn and Co have better solubility in the polar solvent than that of M = Mn and Cu and this is presumably because there are weaker interactions between the organic and inorganic parts in hybrids of M = Zn and Co.
Using a reticulated polyurethane sponge with interconnected pores as primal framework and immersing into TiB2 slurry consisting of Ni and Mo as sintering additives, a porous TiB2 ceramics with high porosity and interc...
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Using a reticulated polyurethane sponge with interconnected pores as primal framework and immersing into TiB2 slurry consisting of Ni and Mo as sintering additives, a porous TiB2 ceramics with high porosity and interconnected pores was prepared by immersing and high temperature sintering process. The rheology of TiB2slurry which used silica sol as a binder was studied. The optimum condition of the slurry suitable for impregnating the polyurethane sponge was obtained. The flexural strength of the porous reticulated TiB2 ceramics can reach 1 MPa.
Based on the empirical electron theory (EET) of solids and molecules, the valence electron structures (VESs) of TiC-Mo(Ni)-Fe system were calculated by building proper structure model. The results indicate that additi...
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Based on the empirical electron theory (EET) of solids and molecules, the valence electron structures (VESs) of TiC-Mo(Ni)-Fe system were calculated by building proper structure model. The results indicate that additives of Mo and Ni improve the interface conjunction factors of the cermets in different ways. By adding Mo, the VESs of the ceramic phase are improved for the formation of the rim phase (Ti1-xMox)C, which leads to the enhancement of the interface conjunction, while the improvement of the VESs on metal phase by adding Ni is due to the formation of the Fe100-yNiy. Mo and Ni additives increase the interface electron density of cermets, that is, the adding of the Mo and Ni enhance the overlapping grade of the electron cloud on interface and increase the binding energy of the interface, which is propitious to the wettability. The best wettability was found at x=0.5 or y=30.
Sodium potassium bismuth titanate (KNBT) slurry with high plasticity was prepared by the viscous polymer processing. The effects of milling time, bonding agent content, dispersant content, and pH value on the rheologi...
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Sodium potassium bismuth titanate (KNBT) slurry with high plasticity was prepared by the viscous polymer processing. The effects of milling time, bonding agent content, dispersant content, and pH value on the rheological properties were investigated by rheograms, and the optimal technological parameters were investigated. The KNBT fibers with improved properties were fabricated via an extruding machine. The results show that the slurry has optimal rheological behavior when the milling time is 16 h, the pH value is 7, the bonding agent content is 1.22% (in mass, the same below), and the dispersant content is 0.4%.
Well-crystallized LiFePO4 cathode materials were synthesized by NaCl-KCl molten salt method. The effect of heating time on the structure, morphology and electrochemical properties of the materials were studied in deta...
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Well-crystallized LiFePO4 cathode materials were synthesized by NaCl-KCl molten salt method. The effect of heating time on the structure, morphology and electrochemical properties of the materials were studied in detail. Single olivine-type LiFePO4 phase was obtained, and the morphology and particle size of the powders could be controlled by changing the synthesis conditions. It was shown that LiFePO4 cathode material synthesized at 680°C for 3h with the salt content N=2 (defining the molar ratio of NaCl-KCl/LiFePO4 as N) had a narrow particle-size distribution and spherical or quasi-spherical shape. Meanwhile, the tap density of the cathode material reached the maximum of 1.501gcm-3. The charge-discharge test indicated that the initial charge and discharge specific capacity reached 138mAhg-1 and 125mAhg-1 respectively at the current density of 0.3mAcm-2.
CuIn1-xGaxSe2 (CIGS) precursor films were fabricated on Mo foils by one-step electrodeposition in water and alcohol solutions. The precursor films were annealed in Ar atmosphere at 450°C to synthesize the polycry...
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CuIn1-xGaxSe2 (CIGS) precursor films were fabricated on Mo foils by one-step electrodeposition in water and alcohol solutions. The precursor films were annealed in Ar atmosphere at 450°C to synthesize the polycrystalline thin films. The current density vs. potential curves of Cu2+, In3+, Ga3+ and Se4+ was studied by cyclic voltammetry. The compositions of CIGS, were analyzed by energy dispersive X-ray spectrum. The morphology and phase structure of films was characterized by scanning electron microscopy and X-ray diffraction, respectively.
A modification analytical model is presented for the thermal elastoplastic stresses of functionally graded materials subjected to thermal loading. The presented model follows the analytical scheme presented by Y. L. S...
A modification analytical model is presented for the thermal elastoplastic stresses of functionally graded materials subjected to thermal loading. The presented model follows the analytical scheme presented by Y. L. Shen and S. Suresh [6]. In the present model, the functionally graded materials are considered as multilayered materials. Each layer consists of metal and ceramic with different volume fraction. The ceramic layer and the FGM interlayers are considered as elastic brittle materials. The metal layer is considered as elastic‐perfectly plastic ductile materials. Closed‐form solutions for different characteristic temperature for thermal loading are presented as a function of the structure geometries and the thermomechanical properties of the materials. A main advance of the present model is that the possibility of the initial and spread of plasticity from the two sides of the ductile layers taken into account. Comparing the analytical results with the results from the finite element analysis, the thermal stresses and deformation from the present model are in good agreement with the numerical ones.
An analytical model of normal ballistic impact on the ceramic/metal gradient armor, which is based on modified Alekseevskii‐Tate equations, has been developed. The process of gradient armour impacted by the long rod ...
An analytical model of normal ballistic impact on the ceramic/metal gradient armor, which is based on modified Alekseevskii‐Tate equations, has been developed. The process of gradient armour impacted by the long rod can be divided into four stages in this model. First stage is projectile's mass erosion or flowing phase, mushrooming phase and rigid phase; second one is the formation of comminuted ceramic conoid; third one is the penetration of gradient layer and last one is the penetration of metal back‐up plate. The equations of third stage have been advanced by assuming the behavior of gradient layer as rigid‐plastic and considering the effect of strain rate on the dynamic yield strength.
The effect of ceramic/metal gradient armor's components characteristic on its impact‐resistant characteristic has been investigated by a new modified Alekseevskii‐Tate equation. The following researching work is...
The effect of ceramic/metal gradient armor's components characteristic on its impact‐resistant characteristic has been investigated by a new modified Alekseevskii‐Tate equation. The following researching work is done by the former model [1]: the effect of ceramic layer on the impact‐resistant characteristic, the effect of gradient layer on the impact‐resistant characteristic and the effect of metal layer on the impact‐resistant characteristic.
Extrusion gelation freeform fabrication process is an extrusion-based freeforming technique capable of fabricating complex shaped monolithic ceramic prototypes by the sequential deposition and solidification of cerami...
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Extrusion gelation freeform fabrication process is an extrusion-based freeforming technique capable of fabricating complex shaped monolithic ceramic prototypes by the sequential deposition and solidification of ceramic suspensions from a computer aided design model. In this process, ceramic parts are produced using an extrusion nozzle suitable for extruding ceramic suspensions. In this study, the processing parameters influencing on manufacturing Al2O3 parts were discussed. Air pressure on top of suspensions, rotating speed of screw, nozzle diameter and scan speed are the main factors to influence the dimensional precision of ceramic bodies. By optimizing these processing parameters, the green bodies were fabricated with high precision. The sintered samples with homogenous microstructure and ∼97.6% relative density could be prepared by sintering of these green bodies at 1600°C for 2 hours.
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