Advanced Materials Research Vols. 239-242

Abstract: The inhibiting behavior of 1-ethyl-3-butylbenzotriazolium ionic liquids，[C₂Bt][Br] ,on mild steel corrosion in 5 wt.% HCl as corroding solution was investigated using weight loss，potentiodynamic polarization and electrochemical impedance measurements. The obtained results indicated that [C₂Bt][Br] is a good inhibitor for the mild steel in 5 wt.% HCl solution. The inhibition efficiency increased with an increase of inhibitive concentration. Potentiodynamic polarization data indicated that the [C₂Bt][Br] acted essentially as a mixed-type inhibitor. The electrochemical impedance study showed that corrosion inhibition took place by adsorption.

Abstract: In order to improve antithermal shock of anodic oxidation membrane on aluminum alloy for heat dissipation substrate of high-power integrated circuit, an organic/inorganic composite membrane on aluminum alloy was investigated through one-trip anodic oxidation. The microstructure, ingredient and performance of composite membrane was characterized through scanning electron microscope(SEM), Energy Dispersive Spectrometer(EDS), microscopic hardness meter, dielectric withstand test station and so on. The results indicated that the structure of composite membrane formed on aluminum alloy 6061 was multilayers piled up of bar-like pieces, which was definately different from traditional anodic oxidation membrane. The breakdown voltage and hardness were 1400V and 282 HV respectively, which were little lower than 1600V and 394HV of traditional anodic oxidation membrane. Composite membrane has a high resistivity in the order of 10¹⁴Ω×cm, which was equal to that of traditional anodic oxidation membrane. However, the antithermal shock properties of composite membrane were more excellent than traditional ones, its did not change after processing 10 cycles of heat/cool treatment. In contrast, the resistivity and configure of traditionals changed significantly. In conclusion, the composite membrane formed with one-trip anodic oxidation possessed good insulation, high antithermal shock, as well as breakdown voltage, which is potential for application as heat disspation substrate in high-power integrated circuit.

Abstract: According to the problem of the influence of oil film thickness on temperature rise for heavy hydrostatic thrust bearing during operation， build viscosity-temperature equation of lubricating oil film and mathematics model of oil film temperature rise of heavy hydrostatic bearing with multiple oil pads, simulate the temperature field of hydrostatic bearing with sector cavity under various oil film thickness using FVM(finite volume method), and reveal the influence law of oil film thickness of temperature rise for hydrostatic bearing. The results show that temperature distribution of hydrostatic bearing is much the same under various oil film thicknesses, but the influence of oil film thickness of temperature rise for hydrostatic bearing is greater. The results of numerical calculations actually response flow state inside hydrostatic bearing ，offer theoretical foundation for the design of hydrostatic bearing in engineering practice, and have important significance in improving operation stability of NC machine.

Abstract: The effects of application of recycled scraps on the composition, microstructure and mechanical properties of SRR99 alloy were studied. The compositions of recycle master alloy are similar to that of the fresh alloy. However, nitrogen content, the size and amount of microporosity increase significantly with the recycle material proportion. Granular, lamellar and strip-like MC particles mainly represent in the interdendritic regions of the revert alloy. With the addition of the recycled material proportion, the amount of the granular ones rapidly drop and the lamellar ones gently enhance. The stress rupture life decline with the addition of the recycled material proportion. The oxide and sulphide inclusions in revert superalloy can be effectively captured and removed by a foam ceramic filter so that the tensile and stress rupture property has been significantly improved.

Abstract: Hydrogenated amorphous silicon (a-Si:H) films were deposited on glass substrates with silane (SiH₄) gas and hydrogen using RF-PECVD method at different power. The phase structure of the films was measured with Raman spectrometer and Panalytical X'Pert PRO X-ray diffraction (XRD), respectively. The optical properties and surface morphology of the films were measured using Shimadzu UV-3600 spectrophotometer and optical digital microscope, respectively. The effects of the environment, including salt water, tap water, acid solution and temperature, on the stability of the films were investigated. The results showed that the phase structures of the films were amorphous, the films can be eroded under salt water and tap water environment, the corrosion resistant stability was improved with increasing the power, the films under acid solution environment appear good corrosion resistant properties, the influence of the environment temperature on the film properties is little. The results had been discussed.

Abstract: In aqueous two-phase system, azodiisobutyronitrile（AIBN） was adsorbed on starch by dissolve- precipitate method. Free radical was then produced by its thermolysis, thus graft copolymerization of starch and acrylamide could be initiated. The effect of factors such as initiating system, organic solvent for AIBN dissolving, time for pre-initiation, concentration of initiator, composition and concentration of disperse system on monomer conversion, grafting efficiency, and dissolution property of the reaction product were studied. The optimum conditions of the reaction were as follows: AIBN was used as initiator and methanol as solvent; pre-initiation time was 25 min; concentration of AIBN was 2.6×10^-4 mol/L; polyethylene glycol (PEG) and polyvinyl alcohol (PVA) was used as disperse system, the ratio of m(PEG):m(PVA) was 2.0:1 and their total mass fraction was 6.5%; both pre-initiation and polymerization temperatures were 60-65 °C. Monomer conversion (C) and grafting efficiency (GE) of the product obtained under these conditions were 99.4% and 99.1%, respectively.

Abstract: The study has examined the influence of FSSW (friction stir spot welding) parameters (rotation speed, downward compression and welding period) on mechanical property (shear resistance force) by conducting FSSW experiments on 3mm-thick AZ31 magnesium alloy plates under the orthogonal design. According to the experiment result, welding period is the major factor that decides the shear resistance force of FSSW joints, optimum welding parameters are: rotation speed(RS) 2450r/min, welding period(WP) 8s, downward compression of the tool shoulder(DCTS) 0.2mm. Microstructure observations show that tiny and even equiaxial grains are formed in WN (Weld nugget zone) and coarse grains with uneven sizes are formed in TMAZ(thermo-mechanically affected zone) and HAZ (Heat affected zone).

Abstract: A novel technique to covalently immobilize indicator dyes with terminal amino groups for preparing optical sensors is investigated. Au nanoparticles are used as bridges and carriers for anchoring indicator dyes on the surface of a quartz glass slide. 1-Aminopyrene (AP) was employed as an example of indicator dyes and covalently immobilized onto the outmost surface of the glass slide. First, the glass slide was functionalized by (3-mercaptopropyl) trimethoxysilane (MPS) to form a thiol-terminated self-assembled monolayer, where Au nanoparticles were strongly anchored via covalent link. Then, 16-mercaptohexadecanoic acid (MHDA) was self-assembled to bring carboxylic groups onto the surfaces of Au nanoparticles. A further activation by using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) converted the carboxylic group into succinimide ester. Finally, the active succinimide ester was reacted with 1-aminopyrene (AP). Thus, AP was covalently immobilized to the glass slide and an AP-immobilized sensor was obtained. The resulting sensor was used to determine rutin based on fluorescence quenching. It showed a linear response toward rutin (R) from 5.0 × 10^-7 to 6.0 × 10^-4 mol L^-1 with a detection limit of 2.0× 10^-7 mol L^-1. This AP-immobilized sensor has very satisfactory reproducibility, reversibility, rapid response and no dye-leaching.

Abstract: The glass samples of SiO₂-Al₂O₃-CdO-Li₂O-K₂O-Na₂O with different Nd³⁺-doped concentration by high - temperature solid-state reaction method were fabricated and the absorption spectrums as well as down-conversion fluorescence spectrums were tested. The experiments confirmed that a strong fluorescence emission at the wavelength of 1064 nm were obtained with pumped wavelength of 514 nm, 532 nm and 808 nm respectively in Nd³⁺ -doped cadmium silicate glasses.

Abstract: The surface of copper plate of the mold need to be reinforced to obtain the plating coatings with high hardness and corrosion resistant properties. Nowadays, Ni-base alloy coatings is used widely in the industrial production. In order to raise the service life of mold, the experiments on the property of Ni-base nano ZrO₂ composite plating coatings was done in this paper. The experiments were planned with the orthogonal test design method. The effective factors on the property of coatings, bath temperature, cathode current density, the distance between two electrodes and the magnitude of Nano-ZrO₂,were experimentally studied. The optimum process parameter were obtained. The results show that the composite plating layer of Ni-base Nano ZrO₂ with good properties can be obtained.The optimal conditions are as follows: the bath temperature is 40 °C, cathode current density is 3A/dm², the distance between two electrodes is 12 cm, the magnitude of Nano-ZrO₂ is 12g/L. In addition binding strength of the coatings were measured quantitatively, and the structure of the plating layer were observed with SEM. The layer with good properties can be obtained in this method.