Advanced Materials Research Vols. 328-330

Abstract: TeO₂-SiO₂ composite films were prepared by electrochemically induced sol-gel method, using ITO glass as a base. The structure of the films was characterized by XRD. The transmission spectrum and reflectance optical spectrum of the film were obtained by a spectrophotometer. In the visible and near infrared range, transmittance of films is greater than 80%;linear refractive index is greater than 2.2. The films electrode was produced by high vacuum evaporation method. The electrical properties of the films were measured by the method of weak current measurement. It was observed that the nonlinear relationship of films’ resistance was characterized by the measured I-V curves, and the tested current was weak. Hence TeO₂-SiO₂ composite films have good optical and electrical properties, and it would be the semiconductor film with the development and application prospects.

Abstract: Co-doped ZnO nanorods membrane was deposited at glass substrate in a simple chemical water bath. The morphology and crystal structure of the samples were characterized by SEM, TEM and XRD. It is shown that the ZnO rods membrane exhibits an excellent orientation along the c axis. X-ray diffraction study also indicates decrease in the lattice parameter after Co doping. The results of EDS and XPS verify that Co²⁺ is successfully doped into the lattice of nano ZnO rods. 2at% and 5at% Co doped ZnO rods behave stronger UV emission and weaker visible emission.

Abstract: Gas-assisted injection molding(GAIM)is a new kind of plastic processing technique. It is one of the most important developments in the injection molding industry. GAIM has many advantages such as lower injection pressure, lower warpage, better surface quality, lower material consumption, and shorten molding cycle time, etc. MPI/Gas module of Moldflow software can be used to simulate the GAIM process to optimize the whole molding process. In this study, the FM new truck interior ceiling handle was analyzed in GAIM process based on the MPI/Gas module. The simulation results showed the gas penetrating time, the contours of plastic layers thickness fraction of the parts and the gas volume fraction changing with time. The results can help technicians to determine the optimum process of the melt injection and the gas injection to ensure the final quality of the parts.

Abstract: The comparison of the efficiency of some natural products (natural honey, vanillin and tapioca starch) on corrosion inhibition of Al-Mg-Si alloy is investigated in seawater solution at room temperature, using potentiodynamic polarization (PP), linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) measurements. The evolution of the corrosion potential (E_corr) and corrosion current density (i_corr) obtained from Tafel extrapolation of polarization curves, and the polarization resistance (R_p) values determined from LPR and EIS measurements indicate that the corrosion rates of Al-Mg-Si alloy decrease with the increasing the natural products concentration. In all cases, the increasing order of inhibition efficiency is: Natural honey < Vanillin < Tapioca starch.

Abstract: The stress-release boot is always used in the fore and rear of SRM grain to relief stress-strain concentration under thermal loading. Since the debonded crack in the stress-release boot may be propagation unstable when the internal pressure entered the debonded crack cavity, the SRM with debonded cracks is very dangerous when it is lunched. So the stability analysis of the debonded cracks is very important to evaluate the defect grain structure integrity. In order to investigate the stability of debonded cracks in the stress-release boot of SRM grain during ignition pressurization, three-dimension (3-D) viscoelastic finite element models of the SRM grain with debonded cracks are established. The 3-D singular crack elements at the tips of cracks are developed to simulate the stress-release boot debonded crack propagation. And all the singular crack elements are included in the 3-D J-integral loop surface to improve the calculation precision. Along with the debonded crack propagation, the 3-D J-integrals of the debonded crack tips are respectively calculated to prejudge its expanding trend. The results show that the most dangerous situation will occur in the fore stress-release boot debonded cracks during the rocket being launched.

Abstract: The paper designs a kind of mobile jumping robot that can choose different movement strategies according to different surroundings. In order to achieve the purpose, we provide the integrated design of the robot which contains the information collection system and the mobile system. Then we describe the hardware structures and the control process in detail. First, we create the mechanical structure and analyze the kinematics model of it. Second, we give the specific design of the mobile actuating mechanisms. At last, we design the hardware circuits and control system of the robot based on TMS320LF2407A chip and put the robot into the experiments. Through the experiments, robot combines the wheeled movement and jumping movement effectively. The ultrasonic sensor is added to robot, and it makes the one smarter than any other traditional robots. The diversity of movement enhances the robot environmental adaptability and expands the range of application.

Abstract: Ti film on AISI 201 was prepared by plasma. The film was characterized by SEM. Their deposition rates were measured by measure the mess of Ti film(m) and the preparation time(t). SEM show that the more time is, the thicker Ti films is. The stronger power is, the thicker Ti films is. And the far the distance is, the more thin Ti films is. It was found that the deposition rates range from 0.02 mg.min^-1 to 0.025 mg.min^-1 at the area of 6.25cm². The deposition rate of titanium film change with the deposition power range from 0.021 mg.min^-1 to 0.163 mg.min^-1. The deposition rate of titanium film change with the deposition power range from 0.096 mg.min^-1 to 0.130 mg.min^-1. The deposition rate of titanium film change with the deposition negative bias range from 0.008 mg.min^-1 to 0.02mg.min^-1 at the area of 6.25cm².

Abstract: The research represents the actual effect of clay and core sand content on the permeability, compressive strength and hot wet tensile strength of green sand by adding clay and core sand into green sand mixture in order to simulate the actual situation of clay and core sand continuously increasing in the used sand during the foundry production. It was found that the content of clay and core sand affect the permeability, compressive strength and hot wet tensile strength of molding sand. With the content of clau and core sand increasing, the permeability of molding sand reduces and has a peak when core sand reaches certain content; the strength of molding sand is high and stable when the content of clay and core sand is below certain amount, and then decreases with the content of clay and core sand increasing. For green sand with resin bonded sand, the effect of clay on hot wet tensile strength appears a curve of “Peak shape”, while for green sand with sodium silicate bonded sand, the effect of clay and core sand on hot wet tensile strength appears “Annual Ring shape” as whose center is the coordinate’s dot.

Abstract: In this study, the abrasive testing machine which was similar to the roller mills was used. It used orthogonal test design and cast iron as the wear material. The main factor effected wear results such as abrasive particle size, rotation speed and rolling gap between the metal materials surface of two rollers were considered in order to find out the best value of each factor and optimize the condition of wheat grinding. Furthermore the wear properties of grain powder on cast iron and wear mechanisms were discussed. The results showed that powder size is the most important factor of the wear properties, the gap is the secondary factor and rotation speed is third. The wear loss is minimal while size is 0.2mm, gap is 0.5mm and rotation speed is 181± 2r/min.

Abstract: A nano-filler network constructed by layered silicates and multi-wall carbon nanotubes (MWCNTs) has been prepared. The structure of the network was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), and dynamic rheological test. The results showed that a plateau in the storage modulus at low frequency occurred, which indicated the pseudo solid-like behaviour for the sample with nano-filler network, and the jamming effect due to the nano-filler network dominated the viscoelatic behaviour at low frequency. This effect was sensitive to the frequency and decreased quickly with the increase of frequency. At the same time, the introduction of nanofillers and the presence of nano-filler network affected the complex viscosity and shear thinning too, especially at low frequency.