Temperature distribution in the sample and the die during the process of Spark Plasma Sintering (SPS) were studied both theoretically and experimentally. The temperature difference is inevitable in the samples in SPS....
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Temperature distribution in the sample and the die during the process of Spark Plasma Sintering (SPS) were studied both theoretically and experimentally. The temperature difference is inevitable in the samples in SPS. Under certain conditions, the difference may reach a few hundreds of degrees of centigrade. Controlling of processing parameters can decrease the temperature difference. The atom diffusion at the interfaces and necks of specimen under SPS was also investigated and compared with Hot Pressing (HP). It was found that the atom diffusion in SPS is faster than that in HP, which indicates that SPS is more efficient.
Extensive dislocation structure was observed by transmission electron microscopy (TEM) in polycrystalline alumina ceramic sintered under a short-time high temperature 1800°C and pressure 100 MPa. There existed lo...
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Extensive dislocation structure was observed by transmission electron microscopy (TEM) in polycrystalline alumina ceramic sintered under a short-time high temperature 1800°C and pressure 100 MPa. There existed lots of dislocation structures: dislocation coalescence, dislocation arrays and dislocation network. The burgers vector of the dislocation array was determined by diffraction contrast as 1/3 less than or equal 11 over-bar 00>. The dislocation network formation was discussed, and it belonged to basal slip system l/3 less than or equal 112 over-bar 0>. Plastic deformation occured mainly by basal plane slip and prime plane slip.
In this paper, transparent Li2O-Al2O 3-SiO2 system glass-ceramic with low expansion was prepared by melting method, using SiO2, Al2O3 Li2CO3 as raw materials, a small amount of alkaline-earth metal oxide, clarify addi...
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In this paper, transparent Li2O-Al2O 3-SiO2 system glass-ceramic with low expansion was prepared by melting method, using SiO2, Al2O3 Li2CO3 as raw materials, a small amount of alkaline-earth metal oxide, clarify additive and nucleating agent (TiO2, ZrO 2). The glass-ceramic was nucleated and crystallized under different temperature and time, according to the DTA. The results show that the glass-ceramic of Li2O-Al2O2-SiO2 system could be obtained by being nucleated at 550°C for 2 hours and crystallized at 550°C for 1 hour. The system was fully compact. The crystal size in the glass-ceramics was small and homogenous, and its main crystalloid was β-quartz. The expansion coefficient of the glass-ceramics was 2.262×10-7/°C(0 [similar to] 900°C)and the density was 2.5 g/cm3.
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.
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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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 excellent properties of ID nanomaterials such as single crystal semiconductor architectures, large surface area, and superior charge transport, which lead to higher photocatalytic activity. We believe that this versatile method can be extent to fabricate other ordered ID nanomaterials films. [ABSTRACT FROM AUTHOR]
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 controllab.e 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.
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.
In the present study, Si2N4 whisker was prepared by thermal decomposition of Si(NH)2, the experimental principles and process were described in detail. Influence factors such as temperature, residual carbon(C), a smal...
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In the present study, Si2N4 whisker was prepared by thermal decomposition of Si(NH)2, the experimental principles and process were described in detail. Influence factors such as temperature, residual carbon(C), a small quantity of oxygen and crucible material that could influence the growth of whisker was analyzed and discussed. The influence degree of each factor and mechanism were explained as well. High quality and modified Si3N4 whisker could be prepared by controlling the influence factors during the experimental process. As a result, it was significant to fabricate batch production of high performance Si3N4 whisker by utilizing this method.
The (Mg0.8Zn0.2)TiO3(MZT) as the foundation is mainly studied to join high dielectric material Ba4Nd28/3Ti18O54·zBi2O3(BNT) to preparation microwave dielectric ceramic 0.7(Mg0.8Zn0.2)TiO3·0.3{Ba4Nd28/3Ti18O5...
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