Applied Mechanics and Materials Vols. 556-562

Abstract: Plasma physical vapor deposition method was most widely used to prepare ultrafine Al powders. Direct Current Arc Plasma (DCAP) and Radio Frequency Induction Plasma (RFIP) were adopted individually to produce Al powders with different particle size. The micro structure such as grain size, morphology and crystal phase was examined by SEM, TEM and XRD methods. The results show that the Al production by RFIP was better than by DCAP. DCAP has outstanding advantages in producing nanoAl powders with the particle size below 300nm while the RFIP is better to produce Al powders with the particle size 300nm to 1 μm.

Abstract: Based on the immersion quenching cooling used at steel bar, numerical simulation about temperature field of big GCr15 bearing steel bar is carried out by the FLUENT. The influence on temperature field uniformity brought by different elements during the immersion quenching cooling is analyzed, such as the number and the diameter of the nozzle when the total cross-sectional area is constant and the distance between the nozzle and the surface of the steel bar. The results show that: a better uniformity of the temperature would be achieved when the number of the nozzle is 11and the diameter of the nozzle is 26mm.when the distance between the nozzle and the surface of the steel bar is 250mm, a better uniformity of the temperature would be gained.

Abstract: Composite to metal joints as important components of marine structures are gradually found in the marine industry. The purpose of this study is to investigate mechanical performance and optimization method of the composite sandwich to steel joints. The main emphasis was placed on the mechanical properties of a hybrid joint between a sandwich glass fibre reinforced plastic superstructure and a steel main hull. Based on the experiments of a base joint, a new finite element method was used to analyze a series of joints. The optimized joint was presented due to reducing weight and enhancing the mechanical performance. The numerical predictions of the base hybrid joint showed a very good correlation with the experiment results, which validated the reliability of the new finite element method. The strength of the optimized joint was also evaluated by finite element method. The result is similar to the base joint. And there is no additional stress concentration in weak parts. The optimized joint has 30% lower weight than the base joint, and the stress is only about 5% ~ 56% of the base one. The results of the present work imply that the change of geometric parameter is an effective method to improve the performance of the metal to composite joint.

Abstract: In recent years, graphene has been increasingly studied due to its good performance, low prices and accessible materials in recent years. In addition, the scaled-up and reliable production of graphene derivatives provides a large range of opportunity to synthesize graphene-based functional materials for various applications. This paper summarizes the graphene-based composites in various fields of applications.

Abstract: In this paper, research the hypereutectic high chromium cast iron by the methed of semi-solid method for cooling inclined plate. Influence of cooling rate on size of primary carbides and mechanical property of hypereutectic high chromium cast iron. The results showed that, speed up the cooling speed can effectively refine eutectic primary carbides in hypereutectic high chromium cast iron. The primary carbides was globularity and slug, provided with excellent mechanical properties. But when the cooling speed is too fast, the pouring temperature is too low, so that the liquid metal has high viscosity, poor mobility. there were a small amount of inclusions in the Preparation of casting. Although still generate pieces of fine carbides in the matrix, but the distribution is not uniform. disadvantage of the comprehensive performance.

Abstract: The patterned magnetic composite microspheres with Fe₃O₄ as core and styrene polymer as shell have been prepared by emulsion polymerization, while the size of microspheres is about 150-200nm. The composite microspheres were characterized by FT-IR, TEM, and TG et al. The measurement results showed that: the magnetic composites were orderly arranged to form a straight line, rhombus, triangle, five-rings-shaped, plum-shaped, six-membered ring geometry by own magnetic action. The structure of microspheres was spherical, the size was uniform and performance is stable.

Abstract: Lizardite were synthesized by hydrothermal reaction in an Fe³⁺ doped solution/environment using nanometer SiO₂ and MgO as precursors. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR). The results show that: the synthetic samples are lizardite with a thickness ranging from 60 nm to 200 nm in the temperature range 200°C~230°C.

Abstract: In order to achieve the metal flow law in high-speed cold roll-beating, the metal flow state was analyzed on the basis of the principle of high-speed cold roll-beating and the Law of Minimum Resistance. The finite element analysis model was established based on the processing of involute spline; high-speed cold rolling forming process was simulated. The equivalent strain and the flow track of a set of nodes on the contact surface on different time are analyzed, the flow law of each node is given, and simulation analysis result is compared with theoretical analysis result.

Abstract: Various CuO-ZnO-ZrO₂(CZZ) catalysts for methanol synthesis from CO₂ hydrogenation were prepared by co-precipitation method. Small amount of silica was incorporated into CZZ catalyst to produce these modified ternary CZZ catalysts. The effects of silica on physicochemical and catalytic properties were studied by TG-DTG,XRD,BET,N₂O chemisorption,H₂-TPR,NH₃-TPD and CO₂-TPD techniques. The results show that the properties of catalysts were strongly influenced by the content of SiO₂ used as promoter. The catalytic performance for methanol synthesis from CO₂ hydrogenation was evaluated. The test results show that the CZZ catalyst modified with 4 wt.% SiO₂ exhibits an optimum catalytic activity. The silica improves the dispersion of CuO and its modified CZZ catalysts exhibits higher specific surface area, which were confirmed to be responsible for excellent performance of the catalysts for methanol synthesis from CO₂ hydrogenation.

Abstract: A novel method of direct aniline multi-interfacial polymerization on paper substrate is introduced in this paper. Cellulose base papers with and without PAE reinforced were discussed. The PANI-paper composites after more than 3 polymerizations had much lower surface resistivity. Their mechanical strength and thermal stability were analyzed by tensile test and GTA. FTIR results explained that there was strong interaction between NH groups in aniline monomers and OH groups in fibers. Conductive composites made with PAE treated paper had both good thermal stability and good mechanical strength with high conductivity.