Advanced Materials Research Vols. 150-151

Abstract: The differences between the Electrochemical Mechanical Machining (ECMM) progress of Particle Reinforced Metal Matrix Composites (PRMMC) and normal metal are the behaviors of non-conductive Particles. This paper employed Finite Element Method (FEM) to analyze the electrochemical reaction around the particle under different parameters. To seek applicable process, the electric filed analysis in the interelectrode gap of the ECMM process with the embedded tools has been adopted. Experiments about work voltage, electrode gap and the formula and concentration of electrolyte dissolution have been done. Through an ECMM hybrid process combined with a fast back grinding process, a surface about Ra 0.5um of PRMMC has been achieved.

Abstract: PTG materials were prepared using TiO2 as photoconductors, silver palmitate as a reducible silver salt, PHZ as a toner and 2246 as a reducing agent in acrylic acid resin binder. The PTG material was coated onto the PET film and then exposed by UV-meter. Effects of the amount of TiO2 and PHZ on the image properties were investigated by means of ultraviolet-visible spectroscopy (UV) and transmission density meter. The formation of silver image was confirmed from the absorption peak around 430nm and X-ray photoelectron spectroscopy (XPS) analysis. The results show that the optimum content is that PHZ of 0.5g and titanium dioxide of 0.03g. The Atomic Force Microscopy (AFM) showed that the triangle-like grains with size of 43nm and height of 10nm grew uniformly on the surface of the exposed PTG film.

Abstract: (La0.7Sr0.3)MnO3 (LSMO) thin films were prepared on Si (100) substrate by pulsed laser deposition (PLD). Both structure and surface morphology of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The results indicate that the films grown on Si (100) substrates have a single pseudo cubic perovskite phase structure with a high (100) orientation. The XPS results show that La, Sr and Mn exist mainly in the forms of perovskite structure and a SrO layer was found on outermost surface.

Abstract: A new composite desiccant composed of ceramic fiber, silica gel and lithium chloride was developed. The adsorption mechanism of the new composite desiccant was analysis based on the adsorption isotherm and the micro character. Compared with the silica gel the chemical absorption accounted for a leading role for composite desiccant. Furthermore the dynamic dehumidification property of the wheel fabricated by composite desiccant was tested. The result showed the composite desiccant wheel need longer time to reach stable dehumidification amounts.

Abstract: This paper examined the in situ growth of hydrophobic anatase TiO2 coating on wood surface using a cosolvent-controlled hydrothermal method. EDXA, FTIR and XRD analysis confirmed that the growth of TiO2 coating on wood surface was bonded to hydrocarbon chains. The relative contact angle of before and after treated wood sample was changed from 46.5o to 136.8o with the examination of contact angle analyzer, which induced a change of the untreated wood surface from hydrophilic to hydrophobic. As observed on SEM image, some slippery TiO2 spheres with about 300-600 nm in diameter evenly dispersed on treated wood surface.

Abstract: ZnO nanodot arrays were fabricated by using AAO template combining with sol-gel method. Structure and optical properties of ZnO/AAO composite structure were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoluminescence (PL). The SEM results indicated that the pores in the template were arranged in a regular hexagonal lattice and ZnO nanodots were assembled into the AAO template. The XRD patterns demonstrated that the AAO template had an amorphous structure, and the ZnO nanodots had wurtzite structures. The PL spectrum revealed that ZnO/AAO composite structure had a strong ultraviolet emission at 390 nm.

Abstract: Ultra-high molecular weight polyethylene fiber plain woven fabric reinforced line-low-density polyethylene composites with different matrix volume fraction were prepared. The interfacial bonding strength and the impact property of the laminates were investigated. The experiment results revealed that the sample with a matrix volume fraction 14% showed better impact properties than other ones, while the interface bonding strength continued to drop when the matrix volume fraction was decreased. It is also indicated that in high fiber interface bonding strength, the impact resistance of the laminate would grow by decreasing the interface bonding strength. However, when the interface bonding strength was lower than the threshold, there would be an opposite effect.

Abstract: By oxygen lance measuring system, under the normal temperature (cold condition) systematic study is carried on traditional supersonic jet flow field that is simulated by compressed-air and on coherent jet flow flied which is accompanied by low density helium in this paper, By commercial software FLUENT, associated with experimental data, the standard double equation K- model is revised appropriately with C1=1.45，C2=1.88. The behavior of axis symmetric jet can be predicted better by simulated results. The flow state of traditional supersonic jet and the characteristic of coherent jet flow flied under vice-hole helium low density concomitance situation are analyzed systematically.

Abstract: An experimental study on collision dynamics characteristics of big concrete block is presented. In order to obtain the recovery coefficient and contact time, a special measuring system is constructed. The experimental results show that the recovery coefficient is increased with the rise of collision velocity but the variation of contact time with collision velocity is opposite. Meanwhile the recovery coefficient of high level concrete is also larger than that of the low level. The inner damage of material in the collision recorded by AE sensors is measured and the results indicated it was the main reason that leads to the energy loss.

Abstract: novel pantograph sliding plate, the network of carbon-copper composites, composed of carbon fiber cloth, copper powder, graphite powder, et al. The physical and mechanical properties of the new samples were tested. Compared with the commonly used pantograph sliding plate, the novel one has lower resistivity, higher bending strength, enhanced impact toughness and better mechanical properties. The new material is suitable for producing the pantograph sliding plate of the electric locomotive.