Advanced Materials Research Vols. 875-877

Abstract: The interface microstructure in the joints of magnesium alloy AZ31 to Ti alloy by the laser welding-brazing (LWB) process have been investigated in this paper. The results indicated that the interface between the solder reaction and TC4 formed net and holes, there was a 1~2 μm intermetallic compound layer. Al-Mg-Zn compounds generated and distributed in the solder reaction zone.

Abstract: In this paper, a novel bionic preparation of anode materials for lithium-ion batteries was reported. Butterfly wings were used as a template to prepare three-dimensional (3D) TiO₂ anode materials. The final product of TiO₂ anode materials maintained the 3D structure of butterfly wings perfectly. The morphology and crystal structure were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM). The electrochemical performance was evaluated by galvanostatic chargedischarge tests. The results showed that the novel 3D porous structure is benefit to the high electrochemical performance

Abstract: Aluminium matrix composite with silicon carbide reinforcement has been developed to increase the hardness of the composite. The determining factors in the development of this material are alloy element content, rolling process and heat treatment. In this research, Al-7Si alloy with Zn and Mg element content variation was made as the matrix to strengthen the aluminium. The reinforcement is silicon carbide (SiC) in the form of particle with volume fraction of 520%. Rolling process and heat treatment were conducted to further increase the hardness. Material characterisation is conducted with chemical composition testing, microstructure observation, and hardness testing. Research showed that after rolling process with 10% reduction, the hardness of composite is increased. The improvement of hardness on precipitation heat treated composite after rolling process tend to decline compare to non-rolled composite.

Abstract: Technology involved in braille display for blind or visually impaired people plays an important role as typical paper form of braille cannot be changed whereas display form of braille can be done at any time. Dielectric elastomers (DEs) are electroactive polymers with low elastic stiffness and elongation, with high dielectric constant have been found for actuator application. In the present study, we have used acrylic elastomer to manufacture a bubble-type actuator and its deformation was examined with increasing electrical field to find its suitability to use as a braille.

Abstract: The Super-hydrophobic surface can be obtained easily by pollution accumulation on room temperature vulcanized (RTV) silicone rubber coating surface. The photos taken by digital camera show that the amount of pollution on the RTV coating surface was increased with time, and after one year, the RTV coating surface nearly could hardly be seen. The water state contact angle (CA) measurement, which was investigated by the static contact angle instrument, reveals that the CA value of RTV coating surface is increased with increasing the pollution accumulation, and in suitable amount of pollution accumulation, the super-hydrophobic surface (water contact angle of 152^o and roll-off angle smaller than 5 ^o) was obtained. The scanning electric microscope (SEM) of RTV coating with different pollution accumulation was investigated. It shows that the continuous micro-nanobinary structure can be formed with enough dust particles on the RTV surface. The mechanism of the effect of pollution accumulation on the wetting property was analyzed, the migration of hydrophobic molecular in RTV coating onto the pollution surface and the formation of micro-nanobinary structure on the RTV coating surface have synergistic effect on the super-hydrophobic surface formation caused by the pollution accumulation.

Abstract: Self-made tension machine was used to measure the evolution of recovery stress under different processing state for NiTiNb alloy. Then, SEM was used to investigate the microstructure evolution. The results show that the range of the highest recovery stress for forged NiTiNb alloy is between 210-215MPa. Otherwise, the recovery stress level of the samples enduring cold drawing and hot rolling is basically same, which all belong to the rage of 210-220MPa. After forging, the firstly precipitated TiNi phase particles become fine, only 5-8μm. The Nb tablets in eutectic microstructure, which originally contributed between TiNi phase particles, appear spheroidization.

Abstract: Recently, the battery industry has represented one important and growing sector where the use of non-toxic and non-hazardous substitute materials has not rapidly developed. The environmentally friendly polymer electrolyte is required to decrease the risk of environmental pollution caused by toxic materials of battery components. Therefore, in this study was focused on the preparation of the environmentally friendly polymer electrolyte membrane with low cost for lithium-ion battery applications. The preparation of polymer electrolyte membrane was done by casting of polymer solution. The main materials used to prepare polymer electrolyte membranes are sulfonated polystyrene (SPS) obtained from isolation of Styrofoam, hydrolyzed bacterial poly(R-hydroxybutyrate) (PHB), and lithium perchlorate (LiClO4) as an ionic salt. The isolated polystyrene was reacted with acetyl sulfate to form sulfonated polystyrene (SPS). These three main materials were dissolved in an appropriate solvent and mixture until homogenous. The polymer solution was poured into a petri dish, and then their solvent was evaporated. The results showed that the increase LiClO4 content in the membranes, the conductivity of membrane increases, but their mechanical strength decreases and the surface morphology of membranes becomes less uniform and homogenous.

Abstract: In this paper the catalytic steam reforming of glycerol to H2 has been evaluated in the presence of Mo/γ-Al2O3 and Mo/γ-Al2O3-MgO in a fixed-bed microreactor at 700 oC. Physiochemical properties of the Mo catalysts were explored by various analytical techniques such as N2 adsorption–desorption (BET), X-ray diffraction (XRD), X-ray fluorescence spectrum (XRF), Temperature-programmed reduction (TPR) and Transmission Electron Microscopy (TEM). Mo/γ-Al2O3-MgO catalysts show promising results with higher H2 concentration produced as compared to Mo/γ-Al2O3 catalysts. The Mo was found to be uniformly distributed on the surface of γ-Al2O3-MgO support and addition of MgO contents into γ-Al2O3 improves the dispersion of Mo on the surface of the support.

Abstract: This paper discussed the compatibility study on the possible materials to replace the existing material used in the cold cutting machine (CCM). The current CCM required a weight reduction and up to 33% was achieved. A reverse engineering process was carried out to investigate the structure and material used. The information gathered to be an input for materials analysis using a Cambridge Materials Selectors software. A comparison of possible replacement materials such as Aluminum Alloy, Carbon fiber reinforced plastic (CFRP), Glass fiber reinforced plastic (GFRP) and titanium alloy was conducted. A prototype cold cutting machine was fabricated and the weight was compared.

Abstract: An experimental procedure for tests on specimens made of several materials is performed to detect the mechanical properties depending from temperature. About 200 cylindrical specimens of several materials (clay, lightweight concrete, aerate autoclaved concrete, mortar) are tested from 20°C to 700°C. The free thermal strain and the decay of axial strength are determined; proposals for the stress-strain curves and the secant modulus of elasticity in function of temperature are illustrated. The data base from tests are able to calculate the collapse domains (bending moment - axial force - time of exposure to nominal fire) which represent a simple model for the assessment of masonry panel sections subjected to fire action.