Advanced Materials Research Vols. 396-398

Abstract: Plating solution of tin free steel (TFS) composes of Cr ions and F ions, which have a characteristic of strong corrosion. The weight loss/gain of the specimens immersed in the test solution was measured by using the electro-balance, to evaluate the erosion of the lead alloy in the corrosive solutions. The results show that lead alloy anode is eroded obviously by F- ions solution, and corrosion rates are constant throughout the examined time. The F- ions concentration have an insignificantly effect on corrosion rate. Corrosion product of anode materials in Cr6+ ions solution is partly deposited on anode materials surface, others might be dissolved into plating solution. This is leading to weight of anode materials remaining almost constant. But the weight of lead alloy anode firstly increases and decreases, then increases using the mixed solution of F- ions and Cr6+ ions as corrosive solution. Corrosion structure variation of lead alloy anode is investigated by means of X-ray diffraction (XRD). XRD results indicate that corrosion product structure is different using different ions solution as corrosive solution.

Abstract: This paper presents a comparison numerical study of the dry and wet granular flows in a cylindrical hopper with flat bottom by means of the discrete element method. A cohesion model is used to examine the impact of moisture presence in hopper flow. It is found that with the increase of Bond number, the discharge rate decreases. The particle force structure inside the hopper is investigated to explain the reason of the lower discharge rate for the wet particle cases. Compared with the dry particle case, in the wet particle case there are more force chains in the transitional zone and near orifice, which causes the lower flowability of particles.

Abstract: This paper studies the influence of carbonization and deoxidizing of V2O5 by carbon coefficient, carbonation temperature and carbonization time at low temperature and gains function equation about the deoxidizing rate and three of the influence factors, which using V2O5 as raw materials and high purity carbon powder as reducing agent. Base on analysing the function , the optimum technological conditions of carbonization and deoxidizing of V2O5 at low temperature are carbon coefficient:0.95, carbonation temperature(carbonization time): the first stage 650°C（3h）and the second stage 900°C（120min）.

Abstract: High temperature brittleness of non-oriented electrical steel containing 0.14wt% phosphorus was investigated by mechanical testing, scanning electrical microscopy (SEM) and Auger electron spectroscopy (AES). The steels were annealed at 800~950°C with hold time of 2~30min under dry hydrogen/nitrogen mixture and wet mixture gas. The mechanical testing results indicated that elongation and bend-to-failure times of steel sheets annealed in wet gas was decreased with hold time extending, and dramatically dropped when it exceeded some value. The critical time of brittleness was become shorter with increase of annealing temperature. It was shown by AES that the phosphorus segregation at grain boundary induced by decarbonizing under wet gas led to inter-granular brittle fracture in the steel sheets.

Abstract: The implementation of the kinetic theory for granular flows added strength to the two-phase flow model in the mini-riser. This model uses simulating and calculating commercial software of Fluent to simulate the mini-riser with 0.012m ID and 3m height. Euler-Euler two fluid model was adopted in two dimensional numerical simulation, according to kinetic theory，the solid stress was calculated based on granular temperature and granular viscosity obtained through simulation which could be used to describe the collision between particles. Simulation results, such as solid phase fraction and solid phase velocity, under different operational conditions basically agree well with the experimental measurement.

Abstract: Here a simple method was developed to fabricate super-hydrophobic membrane with hydrophilic Polyethersulphone (PES) via a sol-gel process. The influences of experimental parameters i.e. the precursor treated time, the baking temperature of the membrane, and the fluorinated time on the hydrophobicity of the membranes were extensively investigated. The correspondent hydrophobicity was crosschecked by the contact angle measurement. For the optimum condition, the contact angle of the resulted super-hydrophobic membrane can be increased to 156°. The FTIR analysis confirmed that the membrane surfaces were covered by hydrophobic functional groups, which resulted in both higher surface roughness and higher heterogeneity, and therefore higher hydrophobicity. The micro/nano-meter crater-like protrusions on the membrane surfaces were observed from the images obtained from both AFM and SEM measurements. Moreover, the spongy holes and the finger-like holes were observed in cortex and intermediate layer respectively, from the cross-section of the SEM images.

Abstract: Abstract: The characteristic of internal structure of filament wound composite is investigated by experiment in this article. Cylinders manufactured by two kinds of fiber, E-glass and carbon, and epoxy resin, are cut into several pieces along the winding direction. The sections of pieces are observed with optic microscope. The result shows that there are two kinds of structure in filament wound composite, laminate area and undulating area, consisting of interwoven fiber band in different directions. Undulating quantity is measured at a series of points along undulating fiber band; a linear model is adopted to model geometrical shape of undulation.

Abstract: AlGaN/GaN high electron mobility transistors (HEMTs) were grown on un-patterned, patterned without mask, and patterned with mask Si (111) substrates by metal organic chemical vapor deposition (MOCVD). The patterns on the Si substrates were fabricated by SiO2 masks and wet etching. Double AlN interlayers grown at high temperature were employed to relax the tensile stress induced by the large mismatches in the lattice constants and the thermal expansion coefficients. Growth characteristics of AlGaN/GaN HEMTs were discussed and analyzed. Before achieving optimized growth conditions, more cracking lines were observed on patterns along the [1-100] orientation than along the [11-20] orientation, resulted from more stable GaN (1-100) facets than GaN (11-20) facets. It is suggested that long patterns should be made along the [11-20] orientation. Micro-Raman measurements showed that Raman shifts at the concave corners are bigger than those at the convex corners, indicating the presence of the larger stress at the concave corners.

Abstract: Heat transfer of condensation has been theoretically and experimentally studied.The calculation formula of heat transfer coefficient outside and inside of bellows was deduced, and corrected through experiment. The calculation results are accordant with the experimental ones, and the errors is less than 10%. The effect of bellows structure parameters and pipe diameter on the enhancement heat transfer has been investigated. It is found that in the steady flow region, the average heat transfer coefficient outside and inside of bellows is 3-5 times than that in a smooth tube under the same conditions, and when considering the increasing in heat transfer area, the effectiveness of enhancement heat transfer is 5-7 times than that in a smooth tube.At the same time, total heat transfer coefficient is 3-5 times and 5-7 times than that in a smooth tube.

Abstract: Large amount of emissions from industrial waste residue to the environment has caused serious pollutions. Utilization way to using industrial waste residue preparing sulfoaluminate cement (SAC) is got much attention of scholars both at home and abroad. It summarized the present researches for preparation of SAC from industrial waste residue (IWR). Sintering temperature, mineral composition, physical properties (fineness, standard viscosity, setting time), mechanical properties (compressive strength, flexural strength) and corrosion resistance of cement clinker were analyzed. Preparation of SAC clinker using IWR is a very promising environmental technology.