Advanced Materials Research Vols. 616-618

Abstract: Creep-fatigue tests were carried out to study creep-fatigue property of P91 steel in many references. There are two kinds of loading control methods. One is controlled by stress, and the other is controlled by strain. In this study the creep-fatigue test data loading controlled by stress are summarized. Based on these data Supported Vector Machine(SVM) method is used to build up the models to predict the creep-fatigue lifetime of P91 steel. The results show SVM method can be used to predict the creep-fatigue life of P91 steel, and the value of insensitive factor is very important. When the value of insensitive factor is small and the training error of the model is small too, but the prediction ability decreases. On the contrary when insensitive factor is increased, the training error will become large, and the prediction ability will increase. So during the training, mean square error should not be regarded as the unique goal function.

Abstract: This paper presents the preparation of bimodal crystalline macro-/mesoporous titania powders by using a pluronic polymer (EO20PO70EO20, P123) as a template through a hydrothermal treatment. The as-prepared powders were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results reveal that the amount of P123 has a significant effect on the surface area of the mesoporous titania. When the mass ratio of P123:TBOT is 1:14, the crystalline macro-/mesoporous titania has the largest surface area (120.96 m2/g), the average pore diameter of this sample reaches a minimum of 6.67 nm.

Abstract: Through the analysis of the development status and application of steel structures in China, the author described the hazards of fire on steel structures and the importance of fire protection for steel structures, introduced the most commonly used fire protection methods for steel structures and meanwhile conducted comparative analysis of several fire-resistant coatings for steel structures to detail the performance characteristics of fire-resistant coatings for the thick, thin and ultra-thin steel structures. In addition, through project examples, the author puts forward choices and construction requirements of steel structures fire-resistant coatings in fire prevention design.

Abstract: Heat conduction performance of particle dispersive composites has been numerically investigated by using Finite volume method (FVM) and fractal theory. The effects of the thermal conductivity of particle and polymer matrix, the volume fraction of conductive particle, the dispersion and reunion form of particles on the effective thermal conductivity of composites are analyzed in detail. Results from the research indicate that thermal conductivities of composites will increase nonlinearly along with the increase of filling fraction of particles. Keeping the filling fraction constant, the dispersion and reunion form and direction of particles has significant effect on heat conduction performance of composite. Simple use of high thermal conductivity particles has limited effect on thermal performance of composites. Enhancing the contacts of particle in the direction of heat exchange and forming high heat transfer channels are the main and economical ways to improve heat conduction performance of particulate filled polymer matrix composites.

Abstract: La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ–samarium-doped ceria (SDC) carbonate thin films are produced on SDC carbonate substrates by the electrophoretic deposition (EPD) method. EPD is performed by fixing the voltage and suspension pH while varying the deposition time to obtain a >20 μm-thick layer. The deposition time of 30 min yields more particle deposits than 10, 15, 20, and 25 min. Thin films with an average thickness of 22.9050 μm are obtained from the EPD technique when the voltage is 20 V and the suspension pH is 5.

Abstract: Ce conversion coating was prepared on the surface of magnesium alloy, and formation of Ce conversion coating was discussed. Structure and resistance to corrosion were measured by scanning electron microscope and electrochemical test system. The results showed the Ce conversion coating was composed of three layers, and it could effectively protect magnesium alloy from corrosion medium.

Abstract: In this paper, unlike the traditional powder metallurgy technology, the titanium hydride is directly used as the starting material to manufacture the titanium and titanium alloy. Thermogravimetric and dilatometric techniques are performed to study the dehydrogenation and shrinkage of TiH2 powders with different particle sizes. The process factors such as the sintering temperature, the sintering time, the heating rate, the compaction density, the compaction methods, and the alloy system, would affect the sintering densification of TiH2 powders and TiH2-Al-V alloy powder. The results shown that the dehydrogenation temperature of the starting and ending of the ball milling TiH2 is lower than that of the coarse TiH2 powders, the finer the TiH2 powder, the lower the temperature. The densification of TiH2 powders is easy due to the combination of dehydrogenation and shrinkage of α-Ti in one process, which creates the fresh dehydrided titanium uniform during sintering, thus leads to rapid densification and very high sintering relative density, higher than 99%. In contrast, it is difficult to achieve a full densification of TiH2-Al-V alloy powder during sintering, which requires dissolution of alloy elements during sintering above its beta transformation temperature. The sintered microstructure of Ti-6Al-4V shows the typical lamellar shaped α+β characteristics, with a uniform alloy element distribution.

Abstract: Serious abrasion occurs in power transmission lines in gale, more wind area, mountain micro- terrain meteorological zone in Xinjiang and coastal monsoon zone in our country in recent year. Carry out analysis on reasons of serious abrasion of the fittings under action of gale. Develop research on improvement of abrasion resistant performance of the fittings, forward method to improve abrasion resistant performance of the fittings from structure, materials and process etc aspects.

Abstract: A new solid cerium complex, was synthesized by 8-hydroxyquinoline and cerium nitrate in the ethanol-aqueous solution. The complex was characterized by elemental analysis and FTIR. The results indicate that the complex is Ce(C₉H₆NO)₃. The tribological properties of the Ce(C₉H₆NO)₃ particles as additive in paraffin oil was investigatedon MRS-10A four-ball tester, the results indicate that Ce(C₉H₆NO)₃ particles as additive can be effective in improving anti-wear ability, in enhancing extreme-pressure capacity. The wear scar width can be decreased 0.3mm when the additive in paraffin oil is about 0.25wt.%, when the additive in paraffin oil is about 0.5wt.%, load-carrying capacity can improve 29%. The morphologies, typical element distribution of the worn surfaces were characterized by SEM and EDS, respectively. Its anti-wear mechanism as follows: A permeating layer with rare earth elements was produced in the frictional sub-surface, the layer modified the microstructure and the lubricating state of the frictional surface.

Abstract: The N, S codoped ZnO was synthesized by microwave assisted hydrothermal method. The N, S codoping narrowed the band gap of ZnO (formed impurity states in the band gap), hence shift light response to range of visible light. Furthermore, the doped ZnO exhibits significantly higher photocatalytic activity than that of pure ZnO for degradation of reactive brilliant blue KN-R aqueous solution under simulative solar irradiation.