Dense SnO2-based electrode ceramics have extensive application prospect in glass electric-melting industry due to the excellent electrically-conductive and chemical property in high temperatures and oxidation environm...
Dense SnO2-based electrode ceramics have extensive application prospect in glass electric-melting industry due to the excellent electrically-conductive and chemical property in high temperatures and oxidation environment. In this paper, dense SnO2-based electrode ceramics doped with MnO2 and Sb2O3 were prepared by pressureless sintering method and the corrosion rate in soda-lime glass liquid as well as the microstructure evolution was mainly investigated. The results suggested that SnO2-based ceramics had good corrosion resistance, and the minimum value was only 2.54×10−4 mm/h when MnO2 content is 1.0% and Sb2O3 content is 0.1%. Composition Elements of Glass liquid were detected in the grain boundary and some intergranular pores. It was found that SnO2 grains remained unchanged, whereas MnO2 was easily dissolved into molten glass liquid. SnO2-based electrode ceramics with dense structure and few amounts of additives had excellent corrosion resistance to the molten glass.
Nanocrystalline titanium dioxide powder was synthesized by in-flight oxidation of titanium dihydride (TiH2) powder in a thermal plasma jet. TiH2 powder was injected into the thermal plasma jet and allowed to react w...
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Nanocrystalline titanium dioxide powder was synthesized by in-flight oxidation of titanium dihydride (TiH2) powder in a thermal plasma jet. TiH2 powder was injected into the thermal plasma jet and allowed to react with oxygen injected downstream the jet. Characteriza- tion of the powder by various analytical tools indicated that the powder consisted of nano-sized titanium dioxide particles consisting predominantly of the anatase phase. It is suggested that the thermo-chemistry of the oxidation process contributes significantly to the formation of nano-sized titania. The large energy released during the oxidation process dissociates the TiO2 particles into TiO(g) and titanium vapour, which recombine downstream with oxygen and form nano particles of TiO2.
Effect of stacking layers on the structure and properties of Ca(Mg 1/3Nb2/3)O3/CaTiO3 (CMN/CT) microwave dielectric heterogeneous thin films prepared was investigated. Precursor solutions for CMN and CT synthesis were...
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In the present study, (1-x)(Sr_(0.88)Bi_(0.08))TiO_(3)-xBi(Mg_(0.5)Ti_(0.5))O_(3) (SBT-BMT) system was synthesized using conventional solid stateprocessing. X-ray diffraction (XRD) and SEM testings were employed to d...
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ISBN:
(纸本)9781457711626
In the present study, (1-x)(Sr_(0.88)Bi_(0.08))TiO_(3)-xBi(Mg_(0.5)Ti_(0.5))O_(3) (SBT-BMT) system was synthesized using conventional solid stateprocessing. X-ray diffraction (XRD) and SEM testings were employed to determine the phase constitution and microstructure of ceramics. SBT-BMT ceramics exhibited moderate dielectric permittivities ((epsilon)_(r)) (>1100 at RT) and low dielectric loss (0.07percent) over the temperature range from -20 to 200 deg C, with flat temperature coefficients of permittivity. In addition, SBT-BMT ceramics were observed to possess dielectric relaxation characteristics and energy densities, being on the order of 1.4 J/cm~(3) at 180 kV/cm was observed for the 0.8S_(0.88)B_(0.08)T-0.2BMT ceramics.
Optical transparency was achieved at infrared region and overall translucent silicon nitride was fabricated using hot press sintering (HPS). The increase in h-BN content decreased the optical transparency. Microstruct...
Optical transparency was achieved at infrared region and overall translucent silicon nitride was fabricated using hot press sintering (HPS). The increase in h-BN content decreased the optical transparency. Microstructral observations shows that the optical, mechanical and tribological properties of BN dispersed polycrystalline Si3N4 ceramics were affected by the density, α:β-phase ratio and content of h-BN in sintered ceramics. The hot pressed samples were prepared from the mixture of α-Si3N4, AlN, MgO and h-BN at 1850°C. The composite contained from 0.25 to 2 mass % BN powder with sintering aids (9% AlN + 3% MgO). Maximum transmittance of 57% was achieved for 0.25 mass % BN doped Si3N4 ceramics. Fracture toughness was increased and wear volume and friction coefficient were decreased with increase in BN content.
Y2O3, Er2O3 and Nd2O3 doped polycrystalline silicon nitride ceramics were prepared by hot press sintering method at 1850°C and 30 MPa pressure. 1 wt.% of each rare earth oxides (REO) were sintered with 3 wt.% MgO...
Y2O3, Er2O3 and Nd2O3 doped polycrystalline silicon nitride ceramics were prepared by hot press sintering method at 1850°C and 30 MPa pressure. 1 wt.% of each rare earth oxides (REO) were sintered with 3 wt.% MgO, 9 wt.% AlN and 87 wt.% α-*** optical, mechanical and tribological properties of REO doped polycrystalline silicon nitride ceramics were investigated. Optical transmittance was measured in visible and near infrared region and found to be 54% transmittance for Y2O3 doped Si3N4 ceramics. β- phase transformation was suppressed with REO addition. High hardness and high fracture toughness were achieved by addition of REO. Adding REO shows good mechanical properties as high strength and toughness. Coefficient of friction of the REO doped silicon nitride ceramics was lower than that of without REO doped silicon nitride ceramics.
In real life, people always move according to a certain paths, for example, walking from one side of corridor to the other side of it, but not passing through the wall, and so on. Therefore, all kinds of possible path...
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In this paper, we establish nonlinear GP model between impact factor of sci-tech journal and related indexes based on genetic programming approach. The proposed GP model utilizes average authors, number of district, n...
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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 ...
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Morphotropic phase boundary (MPB) of (0.8-x)PMT-xPbTiO3(PT)-0. 2PbZrO3(PZ) ternary system (x = 0.4) was studied by X-ray diffraction (XRD). It shows that by comparing with 0.4PMT-0.2PZ-0.4PT sample, after doping with ...
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Morphotropic phase boundary (MPB) of (0.8-x)PMT-xPbTiO3(PT)-0. 2PbZrO3(PZ) ternary system (x = 0.4) was studied by X-ray diffraction (XRD). It shows that by comparing with 0.4PMT-0.2PZ-0.4PT sample, after doping with Ni, c/a remains almost same (about1.009), while both c and a decrease indicating that lattice shrinks. Content of the tetragonal phase TP% of Ni-doped samples increase up to 81.1% when the doping limit of the nickel is reached (y = 0.05), and the dielectric constant Ε was found to increase up to 4570 when y = 0.05 and the Curie temperatures of doping samples were found to decrease from 175°C to 157°C.
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