The Bypass-Electrode GMAW method was introduced. The Siemens's S7-200PLC was used to be the core of the control system. Also the high-speed welding control system was designed and realized. The welding program was...
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The Bypass-Electrode GMAW method was introduced. The Siemens's S7-200PLC was used to be the core of the control system. Also the high-speed welding control system was designed and realized. The welding program was written by STEP7-Micro/WIN language. Sequential control, real-time data acquisition and processing signal were realized by controlling program, displaying by touch screen. The welding parameters of flat surfacing and flat lap welding were ensured with experiments. The results show that the welding equipment has high precision of welding and stable performance characteristics and can realize more stable Bypass-Electrode GMAW process. The weld pool is beautiful and little splash.
The CaF_(2)-4LiF additive was added into SrTiO_(3)ceramics in order to decrease the sintering temperature for compact pulse power *** crystalline structure,microstructure and energy storage performance of sintered cer...
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The CaF_(2)-4LiF additive was added into SrTiO_(3)ceramics in order to decrease the sintering temperature for compact pulse power *** crystalline structure,microstructure and energy storage performance of sintered ceramics were *** CaF_(2)-4LiF additive to SrTiO_(3)ceramics contributes to a notably enhancement of the energy storage *** great enhancement in energy storage density occurred due to the notable increase in breakdown strength and the refinement of *** 2 at%additive,the samples exhibited an average breakdown strength of 31.8kV/mm,and an energy storage density of 1.212 J/cm^(3)which is about 1.4 times higher than pure SrTiO_(3).
Ceramic sintering in microwave field is a new ceramic processing method. In present paper, we detected the microstructures and boundary segregation of BaTiO3 ceramics which were sintered in microwave field. Scanning e...
Ceramic sintering in microwave field is a new ceramic processing method. In present paper, we detected the microstructures and boundary segregation of BaTiO3 ceramics which were sintered in microwave field. Scanning electron microscopy(SEM), and transmission electron microscopy(TEM), and chemical analysis methods were employed to detect the microstructure of BaTiO3, element distribution near the boundary of BaTiO3 ceramic. The results shown growth of grain of the ceramic was influenced by impurities such as acceptor, benefactor et al, and the element distribution near the grain boundary of BaTiO3 sintered in microwave field were different with that sintered in conventional method. The boundary segregations of BaTiO3 sintered in microwave field were not obvious as compared to the conventional method because the diffusion was enhanced due to the microwave field.
Highly oriented titanate nanotube (TNT) film was successfully synthesized by a simple electrophoretic deposition (EPD) method without any hard templates and surfactants. This oriented films adequately utilized the exc...
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The effects of the modification of electrode/ceramic interfaces through a chemical solution deposition-derived PbO buffer layer on the fatigue endurance of lead zirconate titanate（PZT） thin films were *** grain size...
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The effects of the modification of electrode/ceramic interfaces through a chemical solution deposition-derived PbO buffer layer on the fatigue endurance of lead zirconate titanate（PZT） thin films were *** grain size and the surface roughness of the PZT films increased through PbO interfacial ***,the PZT films with PbO interfacial modification had a better crystallographic structure and no evident secondary phases were *** the remanent polarization and dielectric constant were reduced,the fatigue endurance was *** on the results,the mechanism for the fatigue endurance improvement was discussed.
This paper reviews the recent research progress in the hetero-nanostructure of silver nanoparticles on MOx (M=Mo, Ti and Si). It describes the general synthesis of hetero-nanostructure of silver nanoparticles on MOx, ...
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This paper reviews the recent research progress in the hetero-nanostructure of silver nanoparticles on MOx (M=Mo, Ti and Si). It describes the general synthesis of hetero-nanostructure of silver nanoparticles on MOx, and then outlines the interesting catalytic and sensing properties found in these hetero-nanostructures of silver nanoparticles on MOx.
In the present work, silicon nitride nanowires (SNNWs) have been synthesized via nitriding cryomilled nanocrystalline silicon powder. The silicon powder exhibits a fine polycrystalline structure after the cryomilling ...
In the present work, silicon nitride nanowires (SNNWs) have been synthesized via nitriding cryomilled nanocrystalline silicon powder. The silicon powder exhibits a fine polycrystalline structure after the cryomilling process, with an average grain size of 25 to 125 nm at various cryomilling times. The SNNWs that form after the nitridation of the cryomilled silicon powder exhibit single crystal structure and are 20 to 100 nm in diameter and ∼10 µm in length. The diameter of the nanowires is in agreement with the grain size of the cryomilled Si powder. Microstructural characterization reveals that the as-synthesized nanowires have a hexagonal structure and their primary growth direction is along the [0001] direction. The formation of the Si–N–Si bond during the cryomilling process, as investigated theoretically with density functional theory, promotes the subsequent synthesis of the α-Si3N4 nanowires. The mechanism for nanowire formation appears to be a vapor-solid (VS) reaction.
Structural characteristics, chemical bonds and thermoelectric properties of Si-doped boron carbides are studied through calculations of various structural unit models by using a self-consistent-field discrete variatio...
Structural characteristics, chemical bonds and thermoelectric properties of Si-doped boron carbides are studied through calculations of various structural unit models by using a self-consistent-field discrete variation Xα method. The calculations show that Si atom doped in boron carbide is in preference to substituting B or C atoms on the end of boron carbide chain, and then may occupy interstitial sites, but it is difficult for Si to substitute B or C atom in the centers of chain or in the icosahedra. A representative structural unit containing a Si atom is [C-B-Si]ε+ [B11C]ε-, while the structural unit without Si is [C-B-B(C)]δ--[B11C]δ+, and the coexistence of these two different structural units makes the electrical conductivity increases. As the covalent bond of Si-B or Si-C is weaker than that of B-B or B-C, the thermal conductivity decreases when Si is added into boron carbides. With the electrical conductivity increases and the thermal conductivity decreases, Si doping has significant effect on thermoelectric properties of boron carbides.
Aluminum oxynitride (AlON) is a nitrogen-stabilized defective spinel phase of alumina (y-Al2O3). Its structure has not been well understood so far. Solid-state27 Al magic-angle spinning nuclear magnetic resonance and ...
Aluminum oxynitride (AlON) is a nitrogen-stabilized defective spinel phase of alumina (y-Al2O3). Its structure has not been well understood so far. Solid-state27 Al magic-angle spinning nuclear magnetic resonance and quantum chemistry calculation are used to characterize y-Al2O3 and AMON ceramics in the present study. The resonance spectra clearly show different units (e.g. [AlN4], [AlO4] and [AlO6]) and vary with composition. The calculation shows that the vacancy located at octahedral site is more stable than that located at the tetrahedral site, and nitrogen atoms preferentially replace oxygen atoms in the tetrahedral site, which is in agreement with the experimental analysis by nuclear magnetic resonance.
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