Applied Mechanics and Materials Vol. 251

Abstract: The difference in microstructures and properties of 600MPa cold rolled dual phase steel with the different composition had been studied in this paper. It can be noticed that the Si-Mn-Cr steel have finer ferrite and more martensite whose content is about 25%; the Mn-Cr-Mo steel have coarser ferrite and some coarse pearlite as well as little martensite; the microstructures of the Mn-Al-Mo steel are consist of mainly ferrite which have even grain size and 16% martensite which distributed homogenously along the ferrite grain boundaries. The difference in microstructure makes the steel own the different properties. The Si-Mn-Cr steel has the highest tensile strength and yield strength but the worst elongation, the Mn-Cr-Mo steel has the lowest tensile strength, the Mn-Al-Mo steel has the an excellent mechanical properties with low yield strength and high tensile strength as well as higher elongation.

Abstract: Sound insulation equation of steel panel and other insulation materials of compound panel was deduced in normal case, based on the Wave Transferring theory in this paper. Single steel panel and compound steel panel with a certain thickness were predicted theoretically and then measured in the standing wave tube practically. Compared with the two results, the predicted values were matched with the measured values.

Abstract: In this paper, DOE method is applied to scheme test plans for designing the casting processes with shrinkage volume information provided by InteCAST. The effect on casting defect by the setting of riser style, riser section, riser height, chill section, chill thickness were studied by the range analysis, and the influences degree of above five factors were compared by the variance analysis. The trend graphs of factor level are drawn to intuitively present the degree of importance of the factor. Optimal process parameters are obtained by using comprehensive analysis and comprehensive score method. A practical exemplification is shown to prove that the proposed method could help designer effeciently obtain a optimal feeding layout.

Abstract: This paper briefly reviews the nature and application of carbon nanotubes, and the properties of carbon nanotube transport. Pure carbon nanotubes and doped carbon nanotubes at different temperatures are prepared for measuring temperature chemical vapor deposition (CVD). The transport properties are measured and the results are compared. It proves that the experiment error, and the theoretical simulation are consistent with the experimental results. Multi-layer carbon nanotubes verify the conductivity in the CVD growth of carbon nanotubes at room temperature IV curve and low bias nonlinear as shown in the scattering theory. The conductance of carbon nanotubes changes with the temperature decreasing when semiconducting. Carbon nanotubes doped with metal atoms the Fermi level, and thus reduced the conductance of the barrier, making it conductively to guide the performance by a significant modulation.

Abstract: The intermolecular weak interaction between GeH4 and X(X=He, Ne, Ar, Kr) has been studied at MP2/aug-cc-pvtz level. Electron density topological properties of the studied systems have been calculated to investigate the critical points of H…X weak bonds. The molecules electrostatic potential (MESP) image is one of the tools for conformational analysis, and the related data suggests the view of the non-electrostatic weak interaction in nature of the GeH4…X(X=Ar, Kr) systems. To help possible experimental identification of the intermolecular weak interactions described in this work, the frequencies analysis and NMR properties were also calculated at MP2/aug-cc-pvtz level.

Abstract: A potassium hydroxide activation method is used to derive activated carbon (AC), which has high surface area of 1,324.62 m2/g, from agricultural waste, i.e. sugarcane bagasse. The adsorption capacity of AC for Atrazine, a widely used herbicide, in aqueous solution is evaluated at different initial Atrazine concentration, temperature, and pH. The results show the maximum adsorption capacity of Atrazine is proportional to the initial concentration of Atrazine. The amount of adsorption is inversely proportional to the temperature, although there is not significant decrease of adsorption capacity when temperature rises. Furthermore, the pH value has no influence on the adsorption of Atrazine, which shows the AC made of sugarcane bagasse has great performance in adsorption over a wide range of pH values.

Abstract: In this work, tin dioxide was chosen to make tubular ceramic membrane. The morphology was characterized by SEM, XRD and Poremaster. The SEM analysis reveals that the distribution of membrane pore is uniform. The average pore size is 2 μm. Pure water flux is 5.26 m3^{Superscript text}•m^-2•h-¹ at 0.1 Mpa. Porosity of tin dioxide membrane is 40%.

Abstract: Ta-doped In2O3 transparent conductive oxide (TCO) films are deposited on glass substrates by radio-frequency (RF) sputtering at 300°C. The influence of post-annealing on the structural, morphologic, electrical, and optical properties of the films is investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Hall measurement, and optical transmission spectroscopy. The obtained films are polycrystalline with a cubic structure and preferentially oriented in the (222) crystallographic direction. The lowest resistivity of 5.1 × 10−4 Ω•cm is obtained from the film annealed at 500°C, which is only half of that from the un-annealed film (9.9 × 10-4 Ω).

Abstract: Ultrasonic fatigue performance test of 16Mn steel and welded joints are carried out by using ultrasonic fatigue test system devices developed by Tianjin University to research its fatigue behavior in the super long life regime. The results show that: regardless of the base mental or welded joints, the S-N curve is a continuous decline curve; Welded joints does not exist the traditional concept of fatigue limit within the range of 10⁶~10⁷, when the number of load cycles exceeds 10⁷ even 10⁹, fatigue fracture still occurs. Within the super long life range, the fatigue strength of welded joint is much lower than the fatigue strength of base mental. It is dangerous to use the existing fatigue data to design the welded structure within the super long life regime.

Abstract: This paper presents a micro-grinding experiment on soda-lime glass to study the surface quality effective factors during micro grinding on hard brittle materials. The process of micro-grinding on soda-lime glass is showed in this paper and micro-grinding equipments are designed, fz(feed rate), ap (grinding depth), vg(Grinding speed) in micro-grinding brittle materials and their effects to surface quality have been discussed by experiments which were carried out on a desktop micro machine developed by NEU. Results proved that fz is the most important factor to the surface quality, and low surface roughness could be achieved by high vg and low fz in micro-grinding soda-lime glass.