Applied Mechanics and Materials Vols. 182-183

Abstract: The uniform and transparent C-doped TiO₂ thin films were successfully deposited on medical glass slide by arc ion plating. The influences of the C-doped quantity, pulsed negative bias and annealing treatment on films properties were investigated. Film structure, surface morphologies and optical properties were measured with XRD, SEM and UV-VIS transmittance spectroscope. Photo-catalytic performance of the films was evaluated by degrading methyl orange. The results show that the C-doped quantity and annealing treatment have important influence on the absorption edges. The effect of annealing treatment is similar to that of the increasing the C-doped quantity, and they can enhance the C doping and extends the absorption edge. The absorption edges of the films increase with the rising of the C-doped quantity, and all the films absorption edges increase after annealing at 400°Cfor 4h, and the best extending can increase 20nm after annealing. Along with the negative bias increasing, the intensity of rutile diffraction peak increases, but the anatase decreases. The micro-morphology and crystal structure of different C-doped quantity are mutually correspond. The roughness and grain size of TiO₂ films surface decreases significantly with the negative bias increasing. The crystal grains become even and fine, the high bias films surface micro-morphology has rice-like granular shape.

Abstract: Anodic coatings were prepared by micro-arc oxidation on AZ91 magnesium alloys with the addition of 0-8 g/L tannic acid. The influences of tannic acid concentration on the conductivity and coating properties were studied. The result shows that with the increase of tannic acid concentration, the solution conductivity decreases and the coating color becomes dark. In the solution with 4 g/L tannic acid, the obtained coatings are the most uniform and achieve the best corrosion resistance.

Abstract: A series of polypropylene (PP) blends were obtained by blending isotactic PP and different mass fraction of liquid crystalline polyacylates (LCP-A) at a proper process program. The effect of LCP-A as a new nucleator on crystallization behacior of isotactic PP has been investigated with wide angle X-ray diffraction (WAXD), polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The experimental results showed that LCP-A in the PP played a role in the heterogeneous nucleation effect, supplied much crystal nucleus, enhanced the crystallization velocity and temperature, and the spherulites became smaller and more homogeneous. Moreover, β-phase in the PP was induced. In addition, the relative content of β-crystal (K_β) increased with increasing LCP-A content or crystallization temperature, reached a maximum value, and then decreased as the temperature or LCP-A content further increased. K_β of PP with 0.8% LCP-A isothermally crystallized at 125°C for 1h was 21%. POM results that showed the morphology of β and α spherulite disappeared at 156°C and 172°C, respectively.

Abstract: Composite material has many excellent properties, current, receives special attention was paid to its mechanical properties. By adding the dispersed phase can make the strength of the composites than did not join the dispersed phase of pure matrix material strength several times or several times. Composite materials are often called fiber ( or other dispersed phase) reinforced composite materials.

Abstract: As-cast AM60 magnesium alloy was solid dissolved with exercising different pressures to it. The microstructure of the products was characterized by optical microscope and X-ray diffraction. The mechanical properties of the products were investigated by microhardness tester and tensile testing. The results show that increasing the exercising pressure promotes the fracture and dissolution into the α-Mg matrix of the coarse β-Mg₁₇Al₁₂ phases distributed along the grain boundaries with a network appearance. With increasing the exercising pressure, the tensile strength, elongation percentage and percentage reduction of area of the alloy significantly increase, but its microhardness decreases.

Abstract: As-cast AM60 magnesium alloy was solid dissolved with exercising different pressures (atmospheric-pressure, 3, 4 and 5 Gpa) to it and subsequently aged under atmospheric pressure. The microstructure of the products was characterized by optical microscope and X-ray diffraction. The results show that, compared with exercising atmospheric-pressure during solution treatment, exercising high-pressure during this process causes that the α-Mg grains of the subsequent aging alloy are more fine and uniform, while the β-Mg₁₇Al₁₂ phases transform into fine particles and aggregate to form gobbets or strips. In addition, increasing the exercising pressure promotes the precipitation of the β-Mg₁₇Al₁₂ phases of the aging alloy.

Abstract: A mixture of expanded graphite (EG) and iron powders was ball-milled in a high-energy mill under an air atmosphere and subsequently annealed under a vacuum atmosphere. The products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their anti-friction effect used as lubricating additive was investigated by using a tribo-tester. On the surface of the products, graphite encapsulated iron nanoparticles with a size range of 50-150 nm were formed. Compared with only milled EG/Fe powders, the products exhibit a higher crystallinity of graphite and iron. The products have a marked anti-friction effect, and this effect is better than that of the only milled EG/Fe powders.

Abstract: The natural bentonite as raw material, chitosan as a modifier to prepare chitosan modified bentonite. The use of modified bentonite, each dealing with a high concentration of COD monosodium glutamate (MSG)wastewater and coking wastewater .The optimal conditions: mixing time : 10 ~ 12 min;centrifugation time :25 ~ 30min; PH: 8.5 ~ 9.5; dosage: 10~14g / L. The results showed that the treatment of modified bentonite is better than the bentonite and chitosan. The COD removal rate of MSG wastewater and coking wastewater were 60.1% and 82.3%. So the treatment of coking wastewater is efficiency.. By scanning electron microscopy, surface area and X-ray diffraction analysis shows that modification does not change the basic structure of the bentonite only increased the specific surface area of bentonite, and the adsorption capacity of pollutants.

Abstract: The effect of particle size of iron and size of reinforce particle on properties of materials was studied systematically by the specimen current direct heating dynamic hot press sintering. It is found that mechanical properties of composites increase with the increasing particle size of iron. The properties of SiC_p/Fe composites firstly increase and decrease with particle size of SiC and properties are better when size is 15μm.

Abstract: The effect of particle size of iron on properties of pure iron sintered was studied systematically by the specimen current direct heating dynamic hot press sintering. It is found that mechanical properties of pure iron sintered decreased with the increasing particle size of iron. This is because big particle size of iron leads to big grain in microstructure of pure iron sintered.