Advanced Materials Research Vols. 472-475

Abstract: Finite element model for octagon horizontal type vacuum tank was constructed based on the CAD/CAE software SolidWorks. The strength and stiffness of vacuum tank were analyzed. In order to optimize the size of vacuum tank stiffeners by the FEM and optimal design module, the optimization models were constructed, which have the minimized mass as the objective function subjected to the stress and displacement constraints. The results of optimal design were applied to actual production.

Abstract: The effect of low content of Ca （0.9 or less）on the microstructure and mechanical properties of AZ63 alloys were studied in this paper. The results show that, adding a small amount of Ca , the alloy does not generate Al2Ca phase. The calcium dissolved into the matrix or compound phase and have an uneven distribution, but it can improve the distribution of β-Mg17Al12 phase ,refine the grain and improve the mechanical properties. Adding 0.3%Ca to AZ63 (WT%), the microstructure and mechanical properties of alloy are more ideal.

Abstract: The goal of this paper is to study the R&D project under incomplete information. We extend the multi-step quadrinomial option pricing model through a practical case, which is the R&D project of the machinery to deal with mechanical bits and pieces. We pricing the real options valuation (ROV) of the project and show a decision tree, which can provide managers flexible decisions to analyze technology and market uncertainty.

Abstract: Carbon impurity concentration and dislocation density were investigated with optical microscopy and Fourier transform infrared absorption spectrometer in radial direction of large diameter (6-inch) undoped semi-insulating Gallium Arsenide (SI-GaAs) grown by liquid encapsulated Czochralski (LEC). The experimental results showed that their distributions are both “W”-shaped along wafer diameter, which is relatively higher on the center and lower near the center, but highest on the edge of the wafer. The nonuniformity distribution of thermal stress from growth process leads to the “W”-shaped distribution of dislocations in radial direction. The adsorption of matrix elastic strain field around dislocations induces the “W”-shaped distribution of carbon impurity. Dislocations adsorb carbon impurity and carbon impurity decorates dislocations. Dislocation density distribution affects carbon behavior.

Abstract: Abstract. based on the accumulating fatigue damage model, with single ply plate theory and experiment data as the foundation, consider the interaction between adjacent layer and material degradation, a kind of fatigue life prediction method of fiber reinforced composite laminates is developed. The stiffness decline of each ply during cyclic loading is determined by the fatigue damage variable and the load amplitude and the fatigue life of any laminates can be predicted using the fatigue properties of single ply plate. Using this method a 3D Finite element model is established by ABAQUS software and the fatigue life and the fatigue damage evolution of a T300 / QY8911 laminats are analyzed, the results are more closer to the experimental results.

Abstract: A methodology of line-carved relief editing by mesh feature operations was proposed. Feature region of mesh model is firstly identified by curvature criterion. Secondly, profile lines are extracted by such feature operations as clustering, eliminating, retrieving and thinning of feature points. Thirdly, profile lines are optimized by trimming and smoothing operations. Finally, shape of carved curves could be edited by specifying the width and depth of profile lines, and a satisfactory line-carved relief is achieved by nonlinear compression.

Abstract: Adding B-ion additive or Mg-ion additive to Al-phosphate binder to get different binders, and viscosity of Al-phosphate binders and dry strength of their no-bake sand were tested, bonding mechanism among sands of Al-phosphate no-bake sand was discussed by SEM and EDS. Results indicate that Mg-ion additive can increase binder’s viscosity and dry strength of its no-bake sand more obviously than B-ion additive, adding Mg-ion additive and B-ion additive simultaneously is more obvious. Location crack produced is changed from sand surface to binding bridge inner while adding Mg-ion additive and B-ion additive simultaneously ,and fracture mode is changed from adhesive fracture mainly to cohesive fracture mainly, dry strength is improved from 0.86MPa to 2.38MPa.

Abstract: Characteristic part family definition, part family master model feature diagram and XML stored document of master model are given for product variant design. Then, variant design process of part family is elaborated, including searching similar parts and the similarity retrieval mechanism which are studied for the product variant design of part family. Finally, the standard part family and business part family are developed through Java, Pro/E, SQL Server and an example on product variant design is given to testify the validity of characteristic part family and similarity retrieval mechanism.

Abstract: In this paper, the raw silks were soaked in NaSCN solution, and drown to increase the broken strength. The result showed that after the raw silk was in NaSCN solution, the silk could be drown 1.46 times. The broken strength of the drown silk increased greatly. But the broken elongation decreased greatly. The washing process could increase the broken strength of drown silk. After the drown silk was washed with worm pure water, the broken strength of the drown silk could reached to 0.72 GPa, and the broken elongation recovered very well. The FT-IR spectra, DSC and X-ray diffraction spectra showed the drown silk has more oriented β-sheet crystalline structure, and the thermal decomposition temperature of drown silk increased 10 oC than normal silk. The results showed drowing silk is an efficient method to increase the strength of the silkworm silk.

Abstract: Copper-graphite composites were fabricated by spark plasma sintering (SPS) and cold-pressed (CP) processing using a mixture of copper and graphite powders mechanically alloyed. Pin-on-disc wear was used to evaluate the tribological behavior of copper-graphite composites. The results show that the coefficient friction and wear rate decreased considerably with increasing graphite content; with increasing the sintering temperature, the coefficient friction and wear rate just decreased in the same way. XPS analysis of worn surface indicated that better tribological properties are due to a lubricious film covering almost entire worn surface. The presence of this tribolayer improves the friction and wear characteristics when the tribolayer covers almost entire wear surface it effectively restricts metal to metal contact between pin and disc.