Advanced Materials Research Vols. 430-432

Abstract: The Mg-3% Al melt was treated by carbon inoculation and Mn addition. The effects of Mn addition and addition sequence on the grain refinement were investigated. The effect of Mn on the grain refinement of Mg-3 %Al alloy by carbon inoculation was closely associated with the operating sequence of carbon inoculation and Mn addition.Mn has no obvious effect on the grain refinement under the condition that Mn pre-existed in the Mg-Al melt before carbon inoculation. However, Mn played an inhibiting role under the condition that the Mg-Al melt had been inoculated by carbon before Mn addition. The Al4C3 particles should act as potent nucleating substrates for Mg grains in the sample treated by carbon inoculation. However, the Al-C-Mn particles with Al4C3 coating film could be observed in the sample treated by Mn addition and then carbon inoculation. These particles with duplex phase structure should also act as potent nucleating substrates for Mg grains, resulting in grain refinement. The nucleating potency of most Al4C3 particles was possibly poisoned by the formation of Al-Mn-rich coating film or the Al-C-Mn intermetallic compound, resulting in grain coarsening in the samples treated by carbon inoculation before Mn addition.

Abstract: The effects of ultra high molecular weight Polyacrylonitrile (UHMW-PAN) on the rheological behavior of PAN/DMSO solution have been investigated using a cone-plate rheometer in this work. The rheological behavior was characterized by steady shear and oscillation test It is observed from the measurements that, the rheological behavior of the polymer mixture of UHMW-PAN and AMW-PAN makes a difference to the AMW-PAN solution due to macromolecular entanglements, the viscosities of the solutions decreased with the rising of shear rate, shear viscosity rise with the increase of the molecular weight of the UHMW-PAN. For dynamic experiments, a steady increase of both and with the increase of oscillation frequency and molecular weight of UHMW-PAN was seen for all samples. The and increase with the decrease of the temperature or with the increase of the contents of the UHMW-PAN.

Abstract: The microwave dielectric properties and microstructures of an Mg(Zr0.05Ti0.95)O3 ceramic system have been investigated. The compounds were prepared by the conventional solid-state route with various pressure conditions from 25 to 100 Kg/cm2 and sintered at 1420oC for 4 h. The structure and microstructure were analyzed using X-ray diffraction and scanning electron microscopy techniques. The Mg(Zr0.05Ti0.95)O3 had excellent dielectric properties: Q×f ~ 194,000 (GHz), εr ~ 17.9, and τf ~ -43 ppm/oC for the sample at 90 Kg/cm2.

Abstract: The biomass molding is influenced by many factors such as moisture, temperature, Poisson ratio, particle size, length-radius ratio etc. This paper armed to learn the influence of pressures on the biomass molding with different diameter and mainly researched the forces the biomass undergone, including the relationships of molding pressure and the length-radius ratio and that molding pressure and the density. First the material molding process was analyzed and the infinitesimal isobaric model that is pressure vessel model was established. Then this paper analyzed the model and derived these specific mathematics relationships. According to the formulas, this paper used Matlab to program, handled the datum and got the relationship images of the molding pressure and the length-radius ratio and that the molding pressure and the density. Thus it was learned that in plastic deformation area, the pressure and mould radius have the linear relationship while in the shaping area, they have the hyperbolic relationship and the pressure and the length-radius ratio have the linear relationship; Molding density changes with pressure and radius in index.

Abstract: Based on the theoretical and practical demands, this paper makes the systematic analysis on the modeling from the perspective of performance evaluation of the business incubation parks both home and abroad to lay the foundation for constructing performance evaluation system and model to analyze the management of business incubation parks in Zhejiang Province.

Abstract: In-situ tensile tests of extruded 1420 Al-Li alloy were investigated in field emission scanning electron microscope. Results show that the fracture process is as follows: in the initial stage of tension, the dislocation begins to move, and pile up when meeting strengthening phases; the dislocation cuts through the strengthening phases, and induces their break; the subsequent dislocation moves through the broken strengthening phases, leading to the initiating and propagating fast of the cracks; with opening of small cracks produced at multiple sites, the longer cracks form and keep the propagating, at last the main crack form, result in the fracture of the sample. The fracture mode of extruded 1420 alloy is mixture of ductile and transgranular fracture. The weak texture of extruded 1420 sample transformed from texture {001} to {018} similar to texture {001} of cubic system after tension fracture

Abstract: Mg₂Si reinforced hypereutectic Al-Si in-situ composite was prepared and the effects of the isothermal holding temperature and time on Mg₂Si in the composite were researched. The results showed that there were the important effects of holding temperature and time in the solid-liquid phase region of the Al-Si alloy on the size and morphology of Mg₂Si. The size and morphology of Mg₂Si became smaller and round with the rising of the holding temperature and prolonging of the holding time. The suitable technology in the test was obtained, in which when being held at 615°C for 300s, the size of Mg₂Si decreased to 20.54μm and the shape factor of Mg₂Si reached about 0.67.

Abstract: The tool geometric angle and cutting parameters have a significant influence on the titanium alloy milling process by the usage of solid carbide end mills.The physical simulation method was applied to predict the cutting force and temperature by using two comparative sets of simulation data such as the different tool gemetric angle as tool rake angle, helix angle and different cutting parameters such as spindle speed, axial depth of cut, radial depth of cut. Thus are the commonly used methods to simulate and predict the cutting process before the actual production, which can reduce product cost and time.

Abstract: According to the characteristics of the preparation and revision of a Department of steel production equipment used equipment, repair and maintenance procedures, design the whole process of the procedures from the preparation to the implementation, and propose a solution of approval procedures according to the concept of OA workflow. Meanwhile, implement a custom workflow with the concept of relational database design.

Abstract: The concentration of phosphorus at grain boundary of the Ti-IF steel annealed for 180sec at 780°C、810°C and 840°C respectively is measured by auger electron spectroscopy (AES). The results show that the segregation concentration of phosphorus at grain boundary decreases with increasing annealing temperature from 780 to 840°C. The maximum phosphorus concentration at grain boundary is 13.5at% or so for the specimen annealed for 180sec at 780°C. Most of the grains are intergranular crack and there are a few secondary crack for the samples annealed at 780°C and 810°C. The grains grow up and the cleavage planes increase with increasing the annealing temperature from 780 to 840°C.