Titanium diboride (TiB2) was hot-pressed with 5% aluminum nitride (AlN) as a sintering at different sintering temperatures (1700-1900°C). The effects of sintering temperatures on microstructure and mechanical pro...
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Titanium diboride (TiB2) was hot-pressed with 5% aluminum nitride (AlN) as a sintering at different sintering temperatures (1700-1900°C). The effects of sintering temperatures on microstructure and mechanical properties were investigated. The results showed that the composites achieved the better properties when sintered at 1800°C.
A kind of Li2O-Al2O3-SiO2 system glass-ceramics, which had a low coefficient of thermal expansion, was prepared by melting method and used as the ramp-wave generator material. On one-stage light-gas gun, the experimen...
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A kind of Li2O-Al2O3-SiO2 system glass-ceramics, which had a low coefficient of thermal expansion, was prepared by melting method and used as the ramp-wave generator material. On one-stage light-gas gun, the experimental technique for quasi-isentropic compression via the ramp-wave generator was explored. By impacting the ramp-wave generator, quasi-isentropic compression waves with an extended wave's front were produced. The quasi-isentropic loadings to LY12-A1 samples were further realized via the ramp-wave generator. The results showed that the more the thickness of the ramp-wave generator, the longer the front of the generated waves and the lower the rate of the compression. The present research offered a feasible loading means for the quasi-isentropic compression under low pressures.
Mg-W composites with 0-92% W were prepared by spark plasma sintering (SPS) technique at 600°C-30 MPa-5 min. The mechanism of densification was researched and the relation between the mechanical property and the c...
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Mg-W composites with 0-92% W were prepared by spark plasma sintering (SPS) technique at 600°C-30 MPa-5 min. The mechanism of densification was researched and the relation between the mechanical property and the content of W was discussed. The results indicated that W and Mg exit in the composites through mechanical mixtures. The samples with low content of W were spread by partly molten Mg connecting the particles of Mg, the ones with high content of W through molten Mg joining the particles of W together. Increasing the content of W, elasticity modulus and bending strength increase, the Poisson's ratio decreases.
Spark plasma sintering(SPS) prepared transparent AlN ceramics by using different-content CaF2 as sintering aids, preparing porous materials and welding of alloys were researched. SPS shows its merits which could prepa...
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Spark plasma sintering(SPS) prepared transparent AlN ceramics by using different-content CaF2 as sintering aids, preparing porous materials and welding of alloys were researched. SPS shows its merits which could prepare transparent ceramics with high transparency in short time, prepare porous materials with homogeneous and controllable hole under low temperature in short time, obtain quite strong welding junction under low welding temperature and in short soaking time, owing to its special characters.
According to the low friction coefficient pairs under water-lubrication, which contain active pair and passive pair, their materials and performance were designed and studied in this paper. Friction experiments were o...
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According to the low friction coefficient pairs under water-lubrication, which contain active pair and passive pair, their materials and performance were designed and studied in this paper. Friction experiments were on three ceramic composite coatings of active pairs and three excellent friction material groups. Through a pin-on-disc configuration, friction coefficient and wear weight were tested. The morphology of the wear trace was observed by SEM. The discussion was on the constituent design and the microstructure of ceramic composite coatings, the tribological properties of the coatings and passive pair materials on the condition of water-lubrication. The results indicated that friction pairs of three ceramic composite coatings designed under water-lubrication has lower friction coefficient. This can endure better of the corrosion of the seawater and the adhesion of the microorganism, so it was an ideal friction module when it was used in the seawater.
Polycrystalline samples of Sm partially filled skutterudites SmyFexCo4-xSb12 were prepared by melting and Spark Plasma Sintering technique. The results of Rietveld refinement showed that the obtained SmyFexCo4-xSb12 s...
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Polycrystalline samples of Sm partially filled skutterudites SmyFexCo4-xSb12 were prepared by melting and Spark Plasma Sintering technique. The results of Rietveld refinement showed that the obtained SmyFexCo4-xSb12 samples possessed filled skutterudite structures. The thermal parameter (B) of Sm is larger than that of Sb, Fe, and Co, indicating that Sm "rattled" in Sb-icosahedron voids. The effects of filling atom Sm on thermoelectric properties of these compounds were investigated. With the increase of Sm filling fraction (y), electrical conductivity decreased, Seebeck coefficient increased and had a maximum value when y was 0.38; thermal conductivity reduced and had a minimum value when y was 0. 32. At 750 K, the highest figure of merit of 0.68 was obtained for Sm0.32Fe1.47Co2.53Sb12.
作者:
CAO MingHe TIAN Wei LI MingFa SUN WenHua HU MingJi LIU HanXingState Key Laboratory of Advanced Technology for Materials Synthesis and Processing
Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China
The NaNbO3 powders were synthesized and their crystal structure changes were analyzed by ultrahigh pressure up to 6 *** results indicate that the pure NaNbO3 powders can be synthesized at 300℃ under a pressure of 4 G...
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The NaNbO3 powders were synthesized and their crystal structure changes were analyzed by ultrahigh pressure up to 6 *** results indicate that the pure NaNbO3 powders can be synthesized at 300℃ under a pressure of 4 GPa, to sig- nificantly restrain the Na element volatilization compared with the traditional syn- thesis method. It is found that the crystal structure of synthesized NaNbO3 changes from low symmetry to high symmetry with the increase of the pressure.
The synthesis of Ti3AlC2/TiB2 composites was studied by in-situ spark plasma sintering with different volume content of TiB2. Results indicated the bulk Ti3AlC2/TiB2 was fabricated by SPS, which soaked for 8 min under...
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The synthesis of Ti3AlC2/TiB2 composites was studied by in-situ spark plasma sintering with different volume content of TiB2. Results indicated the bulk Ti3AlC2/TiB2 was fabricated by SPS, which soaked for 8 min under a pressure of 30 MPa at 1250°C. The properties of composites was great increased with the addition of TiB2;the Vicker's hardness increased with addition of TiB2 content, the maximum value is 10.4 GPa. The maximum flexural strength and fracture toughness reached maximum value, which were 696 MPa and 6.6 MPa·m1/2 when the volume content of TiB2 was 10%.
Silver-coated glass microsphere core-shell composite particles were used as electric fillers, nitrile-butadiene rubber electric composite materials were prepared by rubber processingtechnology. The formula for compos...
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Silver-coated glass microsphere core-shell composite particles were used as electric fillers, nitrile-butadiene rubber electric composite materials were prepared by rubber processingtechnology. The formula for composite electric rubber material was studied, and the processing technical parameters of it were optimized. The influences of the quantity of shielding filler on the related properties of electric rubber materials were discussed, including conductive capability, mechanics properties and electromagnetic shielding effectiveness. The results showed that the composite electric rubber is light-weight rubber material and has good durability. With increasing volume fraction of electric fillers, the electric property and electromagnetic shielding effectiveness of the electric rubber material strengthen, its mechanics properties decline. And the volume fraction of the filler reached 40%, the volume resistivity of the rubber materials is 7.41 × 10-3 Ω · cm, it has good mechanics properties and electromagnetic shielding properties.
The spores of Ganoderma lucidum were ground and broken to ultrafine particles by high speed centrifugal shearing(HSCS) pulverizer. The characteristics of Ganoderma lucidum spores were analyzed by scanning electron m...
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The spores of Ganoderma lucidum were ground and broken to ultrafine particles by high speed centrifugal shearing(HSCS) pulverizer. The characteristics of Ganoderma lucidum spores were analyzed by scanning electron microscope (SEM), Fourier transform infrared spectrophotometry (FTIR). Ultraviolet-visible pectrophotometer was used to determine the extraction ratio of aqueous solubility polysaccharide between the raw and broken spores. The immunological function on the mice before and after the breaking of spores wan investigated. The experimental results show that after being ground, the sporoderm-broken ratio reachs 100%, the original active ingredients of ganoderma lucidum spores do not change, and the extraction ratio of aqueous solubility polysaccharide is greatly increased by 40.08%. The broken spores show much higher immunological activity comparing with original spores of Ganoderma lucidum.
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