Advanced Materials Research Vols. 476-478

Abstract: The alumina (Al₂O₃) nanofibers were fabricated by electrospinning a viscous mixture of aluminum isopropoxide solution in 10% aqueous solution of PVA followed by calcination at 500~1000 °C. Tools such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric and differential thermal analysis (TG-DTA) were employed to characterize the obtained nanofibers. When the nanofibers were heat treated at 1000 °C, the as-prepared nanofibers have a diameter in the range of 30 ~ 100 nm, and are composed of α-Al₂O₃.

Abstract: The evaluation of livable city is a popular subject. From the main study perspective of livable city, this paper discussed the concept and connotation of a livable city, summarized the current indicators and methods for the evaluation of City Liability, and made the prospects on its future research.

Abstract: Though composites, particularly those consisting of organic materials, have replaced the role of traditional metallic materials in various engineering applications due to their relatively high mechanical strength, low density, flexibility and low cost, their disadvantages caused by relatively high porosity ratio and low crystallinity inherently make this kind of materials the less favorable choices when low permeation property is a major criterion. Here pure aluminum (Al) thin film, which has excellent anti-corrosion property, is introduced into the structure of fabricated composites to improve the composite’s anti-permeation behavior in corrosive environment while the advantageous points of organic composites are exploited at the same time by applying the optimized thermo-mechanical processing techniques in fabrication. Thus greater potentials for organic polymeric composites may be achieved in the future.

Abstract: Temperature generated on the tool-workpiece has significant effect on the cutting performance. This paper present the tool-workpiece temperature result recorded by thermal imaging camera with various cutting parameter applied. The machining was done on ASSAB 720 steel workpiece for continuous and interrupted cutting. Generally, as the cutting speed, feed rate and depth of cut increases, the tool-workpiece temperature for both continuous and interrupted cutting will increase. Specifically, cutting speed increase from 250m/min to 350 m/min, tool-workpiece temperature increase about 25% at each increment level. The tool-workpiece temperature increase about 16% when the feed rate increases from 0.1 mm/rev to 0.2mm/rev. While, 27% increment was recorded when feed rate increase to 0.4 mm/rev. With the increase of depth of cut, the tool-workpiece temperature recorded an increment between 50oC to 65oC for both continuous and interrupted cutting.

Abstract: The Ni-P-W/Al₂O₃ composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/Al₂O₃ composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases linearly with increasing incorporation of Al₂O₃ ratio. Compared with NdFeB magnet and Ni-P-W amorphous alloy coating, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the amorphous alloy coating obviously. However, for the corrosion resistance of Ni-P-W/Al₂O₃ composite coatings with different Al₂O₃ concentration, there is not a linear increase with the Al₂O₃ concentration increasing. The self-corrosion potential of Ni-P-W/Al₂O₃ composite coatings reaches the highest value while increasing incorporation of Al₂O₃ ratio up to 10 g/L.

Abstract: Poly(butyl acrylate-co-methyl methacrylate-co-octavinyl polyhedral oligomeric silsesquioxane) (OVPOSS-P(BA-MMA)) nanocomposites were synthesized by emulsion polymerization. The structures of nanocomposites were characterized by Fourier transform infrared spectrum (FTIR) and solubility experiment. It was shown that the network structures have been formed during the copolymerization. Dynamic mechanical analysis (DMA) was used to investigate the dynamic mechanical and thermal properties. The data indicate that the crosslinking density apparently affects the mechanical and thermal properties of OVPOSS-P(BA-MMA).

Abstract: Composites have become extensively used in aircraft, including the latest Airbus A380 and Boeing 787 models. Due to their high specific strength ratio, the composites can help to reduce fuel consumption. For this reason, small business jets and light aircraft have begun to use composites in their fuselage designs. The main purpose of this study is to analyze the reaction of the composite landing gear of a light sport aircraft (LSA), under loading. Finite element analysis software was used to analyze and compare the static and dynamic loads on the LSA landing gear. Takeoff weight and sink speed, defined by FAR and ASTM, were used as parameters. This work investigated three different types of landing gear materials: aluminum alloy, glass fiber reinforced composite and carbon fiber reinforced composite. The maximum stress, maximum strain and displacement of landing gear of different shapes (leaf, column and tube shapes) was also measured. Of all the samples tested, tube-shaped glass fiber reinforced composite landing gear exhibited the lowest maximum stress under a static load; it also exhibited the smallest maximum strain and y-axis displacement. The results for dynamic load show taht column-shaped landing gear exhibits the smallest maxiumum stress. The results also show that landing gear made with glass fiber reinforced composite exhibits the lowest maximum strain under a dynamic load, while landing gear made with carbon fiber reinforced composite exhibits the largest displacement of the three materials.

Abstract: Polypropylene/cellulose acetate butyrate(PP/CAB) blend fibers were prepared through melt blending and spinning. The dyeability, hygroscopicity, mechanical properties were investigated. The results showed that additional CAB could improve the dyeability and hygroscopicity of PP fibers. With increasing amount of CAB, the dyeability and hygroscopicity was also increasing. The tensile strength and elongation at break exhibited reduced with increasing content of CAB.

Abstract: The SiC ceramic is the perfect ballistic material in the modern war because it has lower density, the weight is lighter and the cost is moderate. In this paper, the shearing academic modular of the epoxy resin matrix composite enforced promiscuously by SiC nano fiber and Twaron staple was built and proved by the way of mathematic deduced and testing validated. And the shearing characteristic was analyzed. The result shows that the total volume percentage of the enforced fiber is bigger, and the shearing modulus of the composite is higher. The modulus of the composite would be higher if that of the matrix is bigger. If the volume percentage of the fiber with lower shearing modulus is bigger, the modulus of the composite would be lower. The mainly factor which influenced the shearing characteristic of the composite is not the shearing properties of the enforced fiber, but that of the epoxy matrix. The effect to the shearing characteristic of the epoxy resin composite enforced by the mixture of SiC nano fiber and Twaron staple is plus certainly.

Abstract: An orthogonal experiment was employed to research the optimized blending formula to obtain the optimized damping property of Ethylene-Propylene-Diene Monomer (EPDM)/ Polyvinylchloride (PVC) composite. The influences of EPDM/PVC blending ratio, glass fiber, HAF and CPE for the EPDM/PVC composites on the damping characteristic were discussed in detail. The results showed that the order of influence factor was CPE>HAF>EMPM/PVC>glass fiber. It is concluded that the optimum formula was EPDM/PVC=60/40, glass fiber=3, HAF=40, and CPE=0 (phr). A better damping capacity EPDM/PVC composite has been acquired by orthogonal experiment method.