通过作者查论文: Zheng Guang Zou

文章题目页数

作者: Zheng Guang Zou, Kai Liu, Yu Fang Shen, Zhi Gang Xiao, Fei Long, Yi Wu
摘要: This work focus on the effects of C vacancy on wetting of Fe to TiC/Fe at the cermet interfaces. We do the whole work using the first-principles density functional theories. The ideal work of adhesion of the pure interface is not big enough, comparing with the expeimental value. Our calculations suggest that the C vacancy at the interface is a very important factor for interface banding of TiC/Fe cermet composite. An adequate quantities of C vacancies at the interface can improve the wetting of TiC/Fe interfaces.
368
作者: Yi Wu, Xin Wang, Fei Long, Yu Fang Shen, Zheng Guang Zou
摘要: Steel-bonded cemented carbide GT35 was fabricated from natural ilmenite by in-situ carbothermic reduction and vacuum pressureless sintering. The effects of C content on the mechanical properties and microstructures of GT35 composites were investigated. As an excellent reducer, carbon provides an impetus for a series of reductive process. C content determines the melting point of the steel matrix, and directly affects the mechanism of dissolving and segregating of TiC particles, forming a netlike microstructure. Besides, the liquid steel whose viscosplasticity is determined by C content was coated on the surface of the composite and refrained the release of CO. The results showed that the good mechanical properties of steel-bonded cemented carbide GT35 composite were obtained with 0.9wt.% C at the same sintering conditions and the density reached 6.12g/cm3, the average bending strength was over 1229MPa after heat treatment, the mean hardness HRC was 69.4. It also showed that in-situ reduction of natural limonite was a feasible way to fabricate good performance GT35 composite with a relatively low cost.
687
作者: Yi Wu, Xin Wang, Fei Long, Yu Fang Shen, Zheng Guang Zou
摘要: In the present study, steel-bonded cemented carbide GT35 has been fabricated from natural ilmenite by in-situ carbothermic reduction and vacuum pressureless sintering. The effect of different carbon source on the mechanical properties and microstructure of GT35 composite was studied. The quality of the composite synthesized from natural graphite is higher than those from other carbon source. Some good results were obtained from experiments: the density is about 6.2g/cm3, and the bending strength is 1390MPa, which higher than that of other samples. The structures and ingredient of different carbon source were analyzed to elucidate their different performance in the reactions.
1140
作者: Zheng Guang Zou, Xiao Min Li, Yi Wu, Fei Long, Dong Ye Yao
摘要: 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.
299
作者: Yi Wu, Chuan Qiang Yin, Zheng Guang Zou, Xin Wang, Xiao Min Li
摘要: Steel-bonded cemented carbide GT35 was fabricated from natural ilmenite by in-situ carbothermic reduction and vacuum pressureless sintering. The effects of Mo-doped on the mechanical properties and microstructures of GT35 composites were investigated. That the good mechanical properties of steel-bonded cemented carbide GT35 with 9wt% Mo were obtained at the same sintering condition that the density reached 6.223g/cm3 and the average bending strength reached about 1155.6MPa after heat treatment, but the hardness dropped the lowest value HRC 60.94 and the difference was not apparent with the change of Mo content. The additive of Mo is beneficial to be refinement of carbide particle size, sphericity of grains and formation of compact composite. In-situ reduction of natural ilmenite was a feasible way to fabricate good performance composite GT35 with a relative low cost.
1633
作者: Yuan Chun Liu, Zheng Guang Zou, Fei Long
摘要: It has been demonstrated that V6O13 is a very attractive cathode materials for rechargeable lithium-ion batteries. Cr3+ was doped to improve its electrochemical property. CrxV6O13(x =0.01~0.05) cathode materials were prepared using NH4VO3 and Cr2O3 as raw material by solid phase method in argon atmosphere. The best electrochemical properties of CrxV6O13 were obtained under the optimum conditions as follows: the argon flow rate is 85mL/min, the heating rate is 5°C /min, the holding time 1h at 180°C, 1h at 300°C and 30 min at 450°C. The structural and electrochemical properties were examined by means of X-ray diffraction, SEM and charge–discharge tests. The results demonstrated that the powders maintain double cavity chain structure regardless of the chromium doping. When the Cr doping of x = 0.03, capacity is highest. Maximum initial discharge capacity is 334mA•h/g, 80% of theoretical capacity. During discharge process there is 6.5 Li+ embedded in the Molecules of doping. After discharge cathode became Li6.5Cr0.03V6O13.
1780
作者: Zheng Guang Zou, Yi Wu, Fei Long, Wen Wu Xu, Dong Ye Yao
摘要: 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.
1119
作者: Zheng Guang Zou, Chuan Qiang Yin, Yi Wu, Xiao Min Li
摘要: Fe-Al intermetallic/TiC-Al2O3 ceramic composites were fabricated by in-situ carbothermic and aluminothermic reduction from natural ilmenite. Synthesis and sintering of the composites were accomplished unanimously in the vacuum hot pressure furnace. The thermodynamic process, the composition, the microstructure as well as the properties of the FeTiO3-Al-C system were studied in detail through theoretical analysis and experimental research. It was shown that the synthesis process started from the melting aluminium, followed by the deoxidation of ilmenite step by step via a series of different valent titanium oxides to form TiC, Al2O3 and Fe-Al as the ultimate productions. The particle sizes are mostly 3-5μm, and their distributions are uniform. Meanwhile, the addition of additives can improve the wettability of alloy to ceramic phases and the combination of the interfaces, giving rise to the properties of the composites as a whole.
1501
作者: Zhi Gang Xiao, Yi Wu, Yu Fang Shen, Zheng Guang Zou, Fei Long, Kai Liu
摘要: First-principles plane-wave pseudopotential calculations of the electron structure and energetics of the interfaces of clean and Ni-doped TiC/Fe are reported. We predicted the atomic structure, bonding, and the interface binding energy of TiC(100)/Fe(100) and TiC(100)/Fe(110). By comparing the interface bonding energy and the total charge density distribution, the interface have priority to combine in TiC(100)/Fe(100) and TiC(100)/Fe(110) ways, where the former’s interface binding energy is higher. So the structure of TiC(100)/Fe(100) is more stable. The doped Ni atoms have preferential access to Fe-based body and form FeNi alloy, and enhance the interface bonding energy, thus effectively reducing the system energy of TiC(100)/Fe(100) and TiC(100)/Fe(110) interfaces, increasing the bonding strength and stability of interfaces of the composite materials.
166
作者: Fei Long, Jian Jun Li, Tao Gu, Zheng Guang Zou
摘要: CuIn1-xGaxSe2(CIGS) precursor films are fabricated on Mo foil by coelectrodeposition. The influence of the applied potential and the electrolyte additive in the process of electrodeposition are discussed. The precursor films are annealed in Ar for a short time to synthesize the polycrystalline thin film. The annealed layers are only phase-pure CuIn0.7Ga0.3Se2 and show a good crystallinity.
758
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