Advanced Materials Research Vols. 391-392

Abstract: The hot-dip aluminized process parameters with respect to the thickness and microstructure of intermetalic layer were investigated using a uniform design of experiments. The measured thickness of intermetalic layer was regressed as first- to third-order polynomial equations of four related parameters, i.e. hot-dip temperature, hot-dip time, diffusion treatment temperature and diffusion treatment time. It was found that the third-order regressed equation was acceptable and appropriate to identify the influences of the investigated parameters on the thickness of intermetalic layer. Comprehensive analysis of the results based on the regressed equation and microstructure could supply believable and optimized process parameters.

Abstract: Surface characteristics including surface morphology and chemical composition of single sisal fiber and their influences on the interfacial adhesion of sisal fiber/phenolic resin composites were investigated by SEM, AFM, and XPS. The results showed that the surface of the untreated single sisal fiber contained a large amount of lignin (up to 51%). Chlorine dioxide treatment could reduce the surface lignin to a low content (20%). Removal of lignin from fiber surface could enhance the interfacial strength of sisal fiber/phenolic resin composites, giving rise to an increase by 36% in tensile strength. These results indicate that the surface properties of single sisal fiber can be tailored to improve the fiber/resin interfacial adhesion.

Abstract: We proposed a method to enhance the heat removal in the synthesis process of PPTA (p-phenylene terephthalamide) by adding liquid nitrogen. Compared to the indirect heat removal method by ice-water bath, the heat removal method with liquid nitrogen can absorb reaction heat in much larger amount, and consequently allows the operation at an obvious lower temperature. The high inherent viscosity (ηinh) of the PPTA suggests that the quality of the product is very high, indicating the good temperature control by using liquid nitrogen. The results indicate that the introducing of liquid nitrogen effectively transfers the reaction heat to avoid overheating during the polymerization of PPTA, with simple operation process and low cost.

Abstract: The bonding intensity of four kinds of ores from Brazil, Australia and South Africa is researched in this study, and the influence factors are analyzed. The results show that, the ores of different types have apparently differences in bonding intensity, ores from Brazil and South Africa have high bonding intensity, while ores from Australia have low bonding intensity; The foundation of generation of effective liquid is adequate liquid phase fluidity and the lower porosity of core ore; The ratio of porosity of core ore and the index of liquid phase fluidity has negative correlation with the bonding intensity.

Abstract: Through analyzing and inspecting the raw materials conditions and process conditions that affect ferrous material reduction in the thermal reserve zone, the article indicates that for the three commonly used ferrous material of blast furnace, sinter, pellets and lump ore, sinter is easiest to reduce and lump ore is most difficult to reduce. And increasing of the size of ferrous material promote the reduction of the ferrous material slightly. With the increase of batch weight, weight loss of ore and coke decrease at first and then increase. With the increase of the ratio of coke/ore, the extent of reduction of ferrous material had not significantly improved.

Abstract: The sinter production is affected by many factors, including total iron content, gangue content and burning loss. These paper analyses changes of three kinds of Australian iron ores in recent ten years, and then draw a conclusion that the assimilability of these three kinds of Australian iron ores are increased. These kinds of changes cause a lot of influence upon sinter production, which means negative influence. Therefore, ore blending constitution is changed by iron ore quality degradation.

Abstract: Paper removed at authors request due to intellectual property dispute.

Abstract: In this paper, the modes of occurrence of the trace elements of Na, K, Fe and Si in SX-Coal and SD-Coal, which were used for COREX process, were analyzed. The coal was treated by wet digestion method and then the content of trace elements was analyzed. After that, the modes of occurrence of the elements were studied by sequential extraction procedure method and analyzed by ICP-OES. The results showed that the content of Na element is the highest and the content of K and Si elements is very low among the four elements in both kinds of coal. Na and K elements mainly exist in the mode of residue in SX-Coal and SD-Coal, and they are tends to enriched in the residue during the pyrolysis. Fe and Si elements mainly exist in the mode of carbonate, iron oxides and manganese oxides in SD-Coal. Fe and Si are tends to be decomposed from the compounds during the pyrolysis.

Abstract: Well-defined CdS nanorod arrays were pepared via a facile one-step hydrothermal approach and Poly (N-vinyl carbazole) (PVK)/CdS nanocomposites were fabricated by spin-coating chloroform solution of PVK on the surface of CdS film. A variety of techniques including scanning electron microscopy (SEM), optical absorption and photoluminescence (PL) were employed to investigate the surface morphology and optical properties of PVK/CdS nanocomposites. Photoluminescence efficiency of nanocomposites decreases compared to pure PVK and CdS nanorod arrays due to quenching through high photocharge generation quantum efficiency and high charge transport between inorganic semiconductor and conducting polymer.

Abstract: 0.2mm thick titanium alloy sheet was butt-welded using micro impulse laser, influnce of the different processing parameter on the surface and cross-section morphology of welded joint was studied , testing the mechanical properties of joints. The result show that argon as a shielding gas, 0.2mm thick titanium alloy to the laser as heat source can be successful butt welding with process parameters of the pulse power 8.8W, pulse width 2.9ms, pulse frequency 7.0HZ, and forming a good welded appearance, the tensile strength and microhardness of welded joints was higher than the base metal. By the needle-like martensite α 'phase composition of the basket-like structure located in the center of the weld.