Advanced Materials Research Vols. 834-836

Abstract: In order to explore the reaction mechanism of preparing SnO₂/C composite materials by biotemplating, multiple samples are prepared by carbothermal-reduction under vacuum from ramie fibers/Sn (OH)₄ precursors, which were prepared from ramie fibers impregnated with Sn (OH)₄ sol. Thermodynamic calculation and experimental research indicate the reaction mechanism of preparing SnO₂/C composite materials is that granular SnO₂ is generated by pyrolysis of Sn (OH)₄ at about 345.7°C,which distributes in the clearance of the ramie carbon. Pellet-like SnO/SnO₂ composites generated by gas-solid and solid-solid reaction is solid solution of SnO and SnO₂ in the Sn-O-C-H reaction system. And the microstructure of the composites changes from block to pellet-like with the increase of Sn content. The results show that the temperature of 631.3°C is the critical temperature that the reduction reaction of SnO₂ and C can occur spontaneously. With the increase of sintering temperature, SnO₂ is reduced to SnO and Sn by agent C and CO, SnO₂ in turn. Furthermore, thermodynamic analysis results coincide well with the experiment data.

Abstract: Ferromagnetic glass-ceramics could be used for magnetic induction hyperthermia. A ferromagnetic glass-ceramic in the system SiO₂-Na₂O-CaO-P₂O₅-Fe₂O₃ has been prepared by melting of the coprecipitation-derived precursor. Using the coprecipitation-derived method, the molecular-scale homogenously glass precursor was obtained. This glass-ceramic contains a unique magnetite crystals precipitate during cooling from melting temperature without any nucleation and crystallization treatment. The crystallization of the glass systems with different component has been systematically investigated by using XRD, as well as vibrating sample magnetometer (VSM).

Abstract: A novel biphasic material has been synthesized from a melt-derived bioactive glass (45S5) and a glass-ceramic obtained from a melt-derived magnetic glass-ceramics for hyperthermia application. The biphasic material obtained from a mixture 1:1 of these components. The phase composition was investigated by XRD. The magnetic property was measured by VSM. The in vitro bioactivity was investigated by simulated body fluid (SBF) soaking experiment. The glass-ceramic shows magnetic behavior and bioactive, useful for hyperthermia.

Abstract: Ferromagnetic glass-ceramics for hyperthermia application were obtained by melting of the co-precipitation-derived precursor from the nominal compositions SiO₂-B₂O₃-Fe₂O₃-SrO-Na₂O. The influence of boron content on magnetic performance of these glasses was investigated. Glass-ceramics were characterized by x-ray diffraction and magnetic measurements. The crystallization behavior of the glasses was investigated.

Abstract: A glass-ceramic belonging to the CaO-Al₂O₃-SiO₂ (CAS) system with different composition of spodumene and doping the Li₂O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li₂O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li₂O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.

Abstract: The 8YSZ ceramic coating material was prepared by hot-pressing sintering, and the mechanical connection between 8YSZ ceramic coating materials and 7075 aluminum alloy through the mosaic structure was presented as a new connection method. The change rules of mechanical properties such as density test, bending strength and toughness in different sintering process were researched. The results show that density is increased and grains are grown up gradually with the increasing sintering temperature without any microstructure defects. The optimal mechanical properties are obtained by sintering temperature at 1500°C.

Abstract: phase diagram is known as Maps of Materials Science. However, the existing precious metal phase diagrams are far from able to meet the needs of the development of the precious metal materials science and technology. In this paper, the recent research achievements of Au-Ag-Y ternary phase diagram by experimental method and Au-Pd-Zr ternary phase diagram by multi-phase equilibrium thermodynamic calculation software were introduced.

Abstract: In view of the problem of bulge particle defect on the surface of hot-dip galvanized sheets, the causes were analyzed by investigating defect characteristics and surface cleanliness of cold-rolled steel sheets. The results show that the cause of bugle particle defect lies mainly in the residual iron on the surface of cold rolled steel sheets, which has not been cleaning off during degreasing and interfere the normal formation of coating. The bugle particle defect can be effectively prevented when the laser-textured work rollers of No.1 stand of HC tandem cold mills are replaced by smooth rollers, because the residual iron on the surface of cold rolled steel sheets can be reduced obviously.

Abstract: Wetting behavior and interfacial characteristic of the Sn-3.5Ag/Ni system are investigated by sessile drop method at the temperature range of 523~773K. The reactive wetting processes demonstrate that: contact angles between the solder and Ni substrate decrease as exponential decay and the equilibrium contact angles decrease monotonously with the temperature increasing. Triple-line mobility is enhanced as the temperature increases. Compositions of the Sn-3.5Ag/Ni interface are identified by EPMA and EDS analysis as Ni₃Sn₄ adjacent to the solder and Ni₃Sn adjacent to the Ni substrate, respectively. The formation of the interface IMC was known to greatly improve the reliability of the solder joints in integrated circuits.

Abstract: Oil-source correlation is the key to trace hydrocarbon accumulation process and predict reservoir position. Under the complicated accumulation conditions, multiplicity of traditional organic geochemistry index takes great difficulty to detail oil-source correlation. Therefore, the purpose of this study is to try a new way to investigate hydrocarbon accumulation. Fingerprint of trace elements was was used to oil-source correlation in this paper. Its applicability was discussed in Tazhong Area in Tarim Basin, which was the typical complex superimposed basin in west China. The result indicated that crude oil from the Ordovician in Tazhong Area was characterized by mixed sources. The contributions of individual sources differed from formation to formation and from block to block. The study result is consistent with that of traditional organic geochemistry analysis. Application of trace elements as indicators is an effective method to oil-source correlation under the complicated conditions.