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.
The need for WC-Co with improved properties, particularly increased hardness and strength combined with increased ductility and toughness, has focused attention on the development of grades with finer and finer-graine...
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The need for WC-Co with improved properties, particularly increased hardness and strength combined with increased ductility and toughness, has focused attention on the development of grades with finer and finer-grained powders and cemented carbides. The aim of this study is to determine the sintering temperature of nanocomposite WC-6Co (wt.%) sample by using an optical microscope under high temperature and a DSC / TG apparatus. The WC-Co sample was prepared from nanocomposite powder by hot-press-sintering at the determined sintering temperature. The phase structure of the powder and sintered samples was investigated. The SEM imaging was performed on fracture surfaces of sintered samples. The density and the HRA of sintered samples were also measured.
Among the preparing methods of ceramic particles reinforced metal matrix composites, the in-situ reaction synthesistechnology has many technical and economical advantages over other traditional methods obviously. Sev...
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Among the preparing methods of ceramic particles reinforced metal matrix composites, the in-situ reaction synthesistechnology has many technical and economical advantages over other traditional methods obviously. Several principal techniques to prepare metal matrix composites by in-situ reactive synthesis method were analyzed in this paper. Based on the analysis, a kind of preparing by using SHS and HP technique which was combustion and in-situ reaction synthesis of dual-phase ceramic reinforced copper-based composites was given. The impact of preparing condition on the structure and the behavior of the material were also researched. At last, some fundamental characteristics of the copper-based composite were studied, compared with the pure copper this kind of copper-based composite kept the electric conductivity and thermal conductivity above 80 percent, at the same time the wear resistance improved 6 times.
A new organic-inorganic hybrid compound （dienHs）2（P2Mo5O23） （1） [dien=NH（CH2CH2NH2）2] has been hydrothermally synthesized and characterized by elemental analyses, IR spectrum, thermogravimetric analysis, and t...
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A new organic-inorganic hybrid compound （dienHs）2（P2Mo5O23） （1） [dien=NH（CH2CH2NH2）2] has been hydrothermally synthesized and characterized by elemental analyses, IR spectrum, thermogravimetric analysis, and the single crystal X-ray diffraction technique. Compound 1 crystallizes in the triclinic system with space group P1 and a=0.9790（2） nm, b=0.9922（2） nm, c= 1.4644（3） nm, α=95.510（10）°, β=98.860（10）°, γ=95.700（10）°, V=1.3895（5） nm^3, Z=2, R=0.0465. The results show that the compound consists of dienH3^3＋＋ and P2Mo5O23^6-, and the heteropoly anion P2Mo5O23^6- is connected to a 1-D chain structure with the protonated dien by hydrogen bonds.
In the present paper, magnesium dititanate (MgTi2O5, M2T) was introduced into aluminum titanate (Al2TiO5, AT) to form AT-M2T solid solution so that the thermal shock resistance of Al 2TiO5 could be kept still good whi...
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In the present paper, magnesium dititanate (MgTi2O5, M2T) was introduced into aluminum titanate (Al2TiO5, AT) to form AT-M2T solid solution so that the thermal shock resistance of Al 2TiO5 could be kept still good while without any decomposition. The effect of MgTi2O5 addition on thermal shock resistance of Al2TiO5 was investigated. The experimental results showed that the thermal shock resistance of Al 2TiO5 began to decrease when a little amount of MgTi 2O5 was added and then rose with the continuous addition of MgTi2O5, even overrunning that of pure Al 2TiO5 when 30mol% MgTi2O5 was contained. It was found that fine solid solution was formed between Al 2TiO5 and MgTi2O5, which enhanced the thermal shock resistance of Al2TiO5.
Highly oriented plate-like rod/tube arrays of ZnO arc synthesized by a solution-based approach at low temperature. The ZnO rod/tube arrays grow oriented vertically on silicon substrate and the intersectant ZnO nanoshe...
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Calcium carbonate particles with different morphologies were fabricated by the precipitation reaction of sodium carbonate with calcium chloride in the absence and presence of the copolymer poly (styrene-alt-maleic aci...
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Calcium carbonate particles with different morphologies were fabricated by the precipitation reaction of sodium carbonate with calcium chloride in the absence and presence of the copolymer poly (styrene-alt-maleic acid) (PSMA) at 80°C, respectively. The as-prepared products were characterized with SEM, XRD, Infrared and BET surface areas. The results showed that the pH of solution and the concentration of PSMA and CaCO3 significantly influenced the morphologies of CaCO3 particles. Various crystal morphologies of calcium carbonate, such as plates, rhombohedras, rods, ellipsoids, dumbbells, peanuts, spheres etc., could be obtained depending on the experimental conditions.
The nano particles of angelica were prepared by high-speed centrifugal sheering (HSCS) pulverizer. The particles were characterized by ZetaPALS light scattering granulometric analyzer, optical microscope and SEM. HPLC...
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The nano particles of angelica were prepared by high-speed centrifugal sheering (HSCS) pulverizer. The particles were characterized by ZetaPALS light scattering granulometric analyzer, optical microscope and SEM. HPLC was employed to determine the content of ferulic acid, which is the indes ingredient of angelica. Experimental results showed that the average size of solid particle was 76.5 nm after nano-pulverization. The great majority of the plant cell was broken. After nano-pulverization, extraction percent of ferulic acid was increased by 12.95%.
As has been discussed, research on the electronic structure between organic and inorganic atoms in hybrid compounds has become important. In our study, DV—Xα method was employed to calculate the electronic structure...
As has been discussed, research on the electronic structure between organic and inorganic atoms in hybrid compounds has become important. In our study, DV—Xα method was employed to calculate the electronic structure of the hybrid compound. The information obtained from the calculation included orbit charge, bonding order, Fermi energy, density of the state, etc. The influence of organic and inorganic parts on the energy band structure of the hybrid compound was discussed based on the calculation results of Fermi energy and density of state. The chemical bonding between organic and inorganic parts in the hybrid compound was also analyzed in detail according to the orbital charges and bond orders.
With the preparation of organic-inorganic layered perovskite-type compounds (C4H9NH3)2MCl4 (M = Mn, Cu) in solutions, X-ray diffraction (XRD), scanning electron microscopy (SEM),thermal gravimetry (TG) and differentia...
With the preparation of organic-inorganic layered perovskite-type compounds (C4H9NH3)2MCl4 (M = Mn, Cu) in solutions, X-ray diffraction (XRD), scanning electron microscopy (SEM),thermal gravimetry (TG) and differential scanning calorimetry (DSC) have been used to characterize the obtained powders. XRD patterns demonstrate that the two compounds have obvious layered structures and SEM pictures reveal that both (C4H9NH3)2MCl4 and (C4H9NH3)2CuCl4 take on obvious sheet-like microstructure. TG&DSC curves indicate that (C4H9NH3)2CuCl4 decomposes at much lower temperature than (C4H9NH3)*** is ascribed to weakening interactions between its organic and inorganic components, which is presumably due to the Jahn-Teller distortion of [CuCl6] octahedra.
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