Translucent AlN ceramics were fabricated using spark plasma sintering (SPS) technique with 3wt% CaF2 as sintering additive. The samples achieved 52.4% maximum transmittance in medium IR region after 10 min holding tim...
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Translucent AlN ceramics were fabricated using spark plasma sintering (SPS) technique with 3wt% CaF2 as sintering additive. The samples achieved 52.4% maximum transmittance in medium IR region after 10 min holding time by spark plasma sintering at 1800°C and 30 MPa pressure in N2. The results from XRD, SEM, TEM and EDX showed that the sintered bodies were densely compacted and highly pure with fine grain size and uniform microstructures. No secondary phases were observed at the grain boundaries and triple grain junctions, which guaranteed good optical property of the sintered bodies.
A novel water-based magnetorheological (MR) suspension is based on the poly(ethy1ene glycol)-coated carbonyl iron particles, which is prepared by the co-sol-gel reaction using carbonyl iron particles as raw materials,...
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ISBN:
(纸本)9812771190
A novel water-based magnetorheological (MR) suspension is based on the poly(ethy1ene glycol)-coated carbonyl iron particles, which is prepared by the co-sol-gel reaction using carbonyl iron particles as raw materials, and water without any other additive. The microshucture, anti-oxidation properties, magnetic and magnetorheological properties of the core-shell particles are characterized by scanning electronic microscopy, transmission electronic microscopy, Fourier transform infrared spectroscopy, thermogravimetric- differential thermal analysis, vibrating sample magnetometer, and ARES2000 rheometer, respectively. The results show that the as prepared particles have core-shell structure with a polymer shell of less than 100 nm and its anti-oxidation property is enhanced due to the compound coating. Both the core-shell particles and its based MR suspension exhibit excellent soft magnetic performance. The based MR suspension shows low zero viscosity and high MR effects, especially greatly improved anti-settlement and redispersibility. The phenomena are attributed to the hydrophilic thin shell of the core-shell particles.
In the present study, α-Si3N4 is prepared by using MgO and Al2O3 as the sintering additives and spark plasma sintering (SPS) technique. The SPS sintering mechanism is discussed. The relationship between the content o...
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In the present study, α-Si3N4 is prepared by using MgO and Al2O3 as the sintering additives and spark plasma sintering (SPS) technique. The SPS sintering mechanism is discussed. The relationship between the content of sintering additives, sintering temperature and relative densities of the samples is analyzed. The results suggest that when the sintering temperature is 1300-1500°C, the content of sintering additives is 6wt.%-10wt.%, the relative density of sintered samples is 64%-96%. When the sintering temperature reaches 1400°C, the content of sintering additives is 10%, the samples can be fully dense sintered and the relative density can be up to 95%. The sintering mechanism is liquid phase sintering. The bending strength of the sintered samples is 50-403MPa and has a close correlation with the relative density.
This paper was the experimental research of photographic progress on BN-303 photo-resist, in which the ultraviolet light was used in exposure. The surface morphology was observed with SEM. It was discussed that the ef...
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This paper was the experimental research of photographic progress on BN-303 photo-resist, in which the ultraviolet light was used in exposure. The surface morphology was observed with SEM. It was discussed that the effect of soft-baking on 3D structure of MEMS, qualitatively. Finally, the optimized technical parameters obtained through experiments were as follows: soft-baking time was 80°C and soaking time was 30 min, under the condition of cleaning oxidized silicon mask with standard methods, activating sample surface for 30 min at drying temperature 200°C, coating photo-resist at 6000 r/min of rotating speed for 15 s with 17 s of exposure time. The above research results might provide some reliable technical parameters for fabricating micro-device.
Novel mesoporous ZnO-SiO2 (MZS) composites with rod-like morphology were synthesized from coprecipitation method, which was the first time to apply this method in the successful synthesis of ordered mesoporous composi...
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Novel mesoporous ZnO-SiO2 (MZS) composites with rod-like morphology were synthesized from coprecipitation method, which was the first time to apply this method in the successful synthesis of ordered mesoporous composites to our knowledge. This direct-synthesis method was more simple, convenient and efficient, compared with the post-synthesis ones. Structural characterization and spectroscopic study were discussed.
This article introduces a process for the growth of one-dimensional oxide nanomaterials that combines rheological phase reaction and hydrothermal self-assembling process. Fundamentals and practical approaches of hydro...
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This article introduces a process for the growth of one-dimensional oxide nanomaterials that combines rheological phase reaction and hydrothermal self-assembling process. Fundamentals and practical approaches of hydrothermal self-assembling process and rheological phase reaction are briefly described. Particular attention is devoted to the rheological self-assembling for the growth of low dimensional oxide nanomaterials. Many examples are shown that the rheological self-assembling is an effective method to prepare one-dimensional nanomaterials, organic-inorganic hybrids and 1-D nanomaterial array for optical-electronic and electrochemical devices and catalysis. Morphologies, microstructures, properties, and application of one-dimensional oxide nanomaterials are reviewed.
Single-phase n-type (AgIn)xPb1-2xTe compounds were synthesized using the melting reaction method. Influences of (AgIn) substituting for Pb on the constituent phases and thermoelectric properties of the (AgIn)xPb1-2xTe...
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Single-phase n-type (AgIn)xPb1-2xTe compounds were synthesized using the melting reaction method. Influences of (AgIn) substituting for Pb on the constituent phases and thermoelectric properties of the (AgIn)xPb1-2xTe(x=0.01-0.05) were investigated. Results indicate that single phase compound is obtained when the (AgIn) substitution fraction x&le0.04. However, the second phase (AgInTe2) was observed in the sample with x=0.05. The Seebeck coefficient increases gradually with the increasing of the (Agin) substitution fraction x, and the electrical conductivity of the compounds decreases with the increasing of x. Thermal conductivity decreases with the increasing of x. In all of the n-type (AgIn)xPb1-2xTe compounds, (AgIn)0.01Pb0.98Te compound has the greatest ZT value, reaching 1.1 at 800K.
Nearly single-phase and polycrystalline charge-density-wave compound K0.3MoO3 have been prepared by using a simple method. In this work, K2CO3 and MoOs were used as starting materials and reacted by hot isostatic pres...
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Nearly single-phase and polycrystalline charge-density-wave compound K0.3MoO3 have been prepared by using a simple method. In this work, K2CO3 and MoOs were used as starting materials and reacted by hot isostatic pressing （HIP） sintering. The product is nearly single phase K0.3MoO3 determined by X-ray powder diffraction （XRD） and energy dispersive spectroscopy （EDS）. Measurement of temperature dependence of resistivity reveals that the transport property of polycrystalline K0.3MoO3 obviously differs from that of single crystal due to the grain boundaries and the anisotropic structure in this kind of compound.
As one of the advanced functional inorganic power materials, nanometer ZnO has extensive application fields. The specific surface area is considered to be a big factors for its application. In this paper, the gas adso...
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As one of the advanced functional inorganic power materials, nanometer ZnO has extensive application fields. The specific surface area is considered to be a big factors for its application. In this paper, the gas adsorption method was adopted to measure ZnO specific surface area, and the influences of different testing conditions on the results were studied. It was found that optimal testing condition is that sample weight, degas temperature and degas time are 0.3-0.5g, 250°C, 2h respectively.
The method of single detector, direct contact and longitudinal wave were used in this research. Ultrasonic wave attenuation coefficient of nine WC-10 Co hardmetals samples were tested, while fracture toughness values ...
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The method of single detector, direct contact and longitudinal wave were used in this research. Ultrasonic wave attenuation coefficient of nine WC-10 Co hardmetals samples were tested, while fracture toughness values were obtained by indentation method. SEM was performed to observe the sections of the samples. Distributions of the WC grains were analyzed. Density, Vickers hardness and transverse rupture strength were also tested. The relationships among ultrasonic wave attenuation coefficient, mean grain size, fracture toughness, density, Vickers hardness and transverse rupture strength were studied. Results showed that with the decrease of the mean WC grain size, the ultrasonic wave attenuation coefficient and the fracture toughness value increased. However, ultrasonic wave attenuation coefficient had no direct relation with density, Vickers hardness and transverse rupture strength. It was concluded that ultrasonic wave attenuation coefficient could be used to evaluate the fracture toughness of WC-10 Co hardmetals, instead of destructive mechanical method.
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