Applied Mechanics and Materials Vol. 189

Abstract: A room-temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4), was synthesized with two-step method, and putting p-benzenediol and AgNO3 ethanol solution into [bmim]BF4, ultra-fine silver powder were prepared successfully in this paper. The effects of the temperature and material mol ratio of AgNO3 and p-benzenediol on the shape of products were studied. The products were characterized by XRD, SEM, IR and TEM. The results showed that the particle size of silver was much smaller and in the range of nanometers, and had narrowly, uniform distribution, which indicates that the synthesis method using ionic liquid, is the better “green” and “environment friendship” method to prepare ultra-fine silver powder for electromagnetic shielding.

Abstract: Preparation of single-phase and high purity nanophase TiO2 powders with small crystallite size were investigated by microwave hydrothermal method. By varying starting materials and reaction condition, four titania powders were prepared. Single-phase and high purity nanocrystalline anatase was obtained by hydrolysis of Ti(C4H9O)4 at 120oC for 3 h, which exhibited granulous and uniformly dispersed, with the average crystallite size of 10 nm. Well crystallized and single-phase rutile was obtained by hydrolysis of TiCl4 first at 120oC for 1.5 h and then at 180oC for 1 h, which exhibited shuttle-like and well-dispersed TiO2, with average diameter of 10 nm, by means of XRD and TEM.

Abstract: The silver films of nano-structured are prepared by magnetron sputtering on the surface of polyester plain weave fabric,The effect of vacuum pressure on the morphology of the nano-structured silver films,anti-UV and the conductivity of samples deposited with silver films is investigated.Results of experiments show that the surface roughness of silver film with substrate for plain weave fabric is biggest, particle size is largest and particles formed on the surface of films is distinctest when pressure is 0.6Pa,but the conductivity of silver film is optimum when pressure is 0.3Pa; The samples deposited with silver films show better UV absorption, Ar gas pressure has no obvious influence on the samples shielding UV radiation.

Abstract: Indium tin oxide (ITO) and indium tin zirconium oxide (ITZO) films were deposited on glass substrates at room temperature by magnetron sputtering technology with one or two targets. Electrical and optical properties of ITO and ITZO films by air-annealing treatment were contrastively studied. ITZO films provided with the preferential crystalline orientation change from (222) to (400) plane, as well as the increase in grain size and the decrease in surface roughness. As result, zirconium -doping remarkably improved the optical-electrical properties of the films deposited at room temperature. The resistivity of ITO and ITZO films showed the trend which includes first dropping and then rising, which was closely related with the variations of carrier concentration and mobility. ITZO films had high optical transmittance of above 80% at lower annealing temperature. ITZO films prepared by co-sputtering reveal better optical-electrical properties.

Abstract: The article prepares the jet ink with nano-silver synthesized by the lab and then adjusts the parameters of the silver colloid to fabricate nano-silver conductive ink suitable for ink-jet. Then patterns are obtained on the photo paper through EPSON ME 70 jet printing, and treated by three post-processing methods include laser sintering, heating, and solution soaking, which measured by four- point probe measurement and observed by SEM. It shows that after treatment the surface resistance of the patterns all decrease obviously. Patterns heated at 120°C for 10min, the resistance is 815mΩ/□, while the surface changes of silver layers can be observed obviously from SEM images. But the surface of the photo paper is destroyed with some bubbles on the coating surface. After 10min of laser sintering, the resistance of the silver layer reaches 890mΩ/□ from infinity. And when immersed in the NaCl solution for 5min, the patterns’ surface resistance decrease to 2.7Ω/□.

Abstract: Using Faber and Ziman depolarized scattering function theory and modified Kaplow method for eliminating cut off error，the structure of amorphous silica nanoparticles synthesized by a flame CVD process has been investigated. From measured intensities, reduced scattering intensity and radial distribution functions and thus the average atomic distance and the nearest coordination number were obtained. And the influence of particle size on the structure of the amorphous silica nanoparticles was also reported.

Abstract: Titanium carbonitride (TiCN) films were deposited on AZ31 magnesium alloy by radio frequency magnetron sputtering. The surface morphology and microstructure were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the corrosion resistance was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results show that TiCN coatings deposited on AZ31 magnesium alloy are amorphous, and reveal good adhesion onto the substrate. The corrosion current density of TiCN-coated magnesium alloy was 1.664×10-6 A/cm2, which decreased by more than one order of magnitude compared to the uncoated magnesium alloy (1.785×10-5 A/cm2).

Abstract: Plastic anisotropy of the as-rolled 7050 aluminum alloy plate with T7451 temper was investigated by tensile tests, OM, SEM and TEM. The results show that the as-rolled 7050 aluminum alloy plate shows plastic anisotropy. The values of the as-rolled 7050 aluminum alloy plate deformed along ST, LT and RD are 7.178%, 10.69% and 12.877%, respectively. The as-rolled 7050 aluminum plate can be considered as a materials with two phases. Microstructure, especially grain shape and precipitate configuration, is the main source of plastic anisotropy of the as-rolled 7050 aluminum alloy plate with T7451 temper.

Abstract: The effects of aging treatment on the damping capacities of ZA84-xSb alloys were studied. The results show that in the aging treatment process, because of following mainly reasons: (1) the dissolution of the ternary phases, (2) the increase of grain interfaces, (3) the increases of dislocation density, and (4) the micro deformations of matrix interfaces and the second phases, the damping capacity of ZA84-xSb magnesium alloys did not be reduced. On the contrary, whether at the low temperatures or high temperatures, its damping capacity is higher than as-cast alloy, which is of great significance for the application of ZA84-xSb magnesium alloys.

Abstract: As-cast AM60 magnesium alloy was solid dissolved for 40 min at 450 °C under different pressures, atmospheric pressure, 3, 4 and 5 Gpa. The microstructure of the products was characterized by optical microscope and X-ray diffraction. The results show that increasing solution pressure promotes the fracture and dissolution into the α-Mg matrix of the coarse β-Mg17Al12 phase distributed along the grain boundary with a network appearance.