Materials Science Forum Vols. 544-545

Abstract: A novel method to examine the defect of aerial complex material is presented in this paper. The novel speckle averaging technique for DSPI static measurement is proposed to improve the quality of measurement. A speckle averaging mechanism is designed and fabricated. The measurement result of sandwich structure material of practical aviation engineering is presented. The defect in the final results is clear.

Abstract: Vacuum plasma sprayed (VPS) hydroxyapatite (HA) coatings with silver-loaded zirconium phosphate antimicrobial have been prepared on titanium substrate. Antibacterial effects of the coatings were studied by bacteria culturing using Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn) and Actinobacillus actinomycetemcomitans (Aa) as microorganisms. Simulated body fluid (SBF) test was carried out to evaluate the bioactivity of the coatings as well. The results obtained showed that the coatings exhibited a marked antibacterial effect against Pg, Fn and Aa when the content of antimicrobial was equal to or more than 5%. The antibacterial capability of the coatings decreased in the following order: Pg, Fn, Aa. Bone-like apatite layer was formed on the silver-containing HA coatings after immersed in SBF, suggesting that their bioactivities were not affected obviously by the addition of silver-zirconium phosphate antimicrobial. This study indicated that silver-containing VPS HA coating is a prospective candidate as dental material.

Abstract: The alignment precision of the electron lenses is one of the most critical factors that determine overall performance of the microcolumn system including the image resolution and aberration. Since the lens apertures are usually as small as 5 ~ 300 μm, the alignment is difficult to carry out, even if the expensive and complicated aligner is used. In this work, we have developed a novel alignment method using laser diffraction pattern, with which we can easily obtain high-precision alignment. The images of Cu grid (mesh# 1000) and carbon nanotubes (200-nm diameter) taken by the microcolumn fabricated by the new alignment scheme has confirmed that the new method was very simple and useful.

Abstract: The W coatings were prepared by applying the vacuum plasma spraying process (VPS). The phase composition, microstructure and laser irradiation property were characterized by XRD, SEM and laser. Results showed that no tungsten oxide appears in the coatings whose phase composition is similar to the original powder. A better melting state of the coating can be obtained by using the finer powder. The deposition efficiency of the coating is higher in the cases of a higher H2 flow. There is a pitch whose size is about 100μm when the substrate was irradiated by laser. However, there is clearly no change for the W coating surface which was also irradiated under the same condition. It indicates that the laser irradiation resistance is improved significantly for stainless steel after being deposited with W coating.

Abstract: A new technique preparing polyester fiber impregnated with organic phase change material(PCM) was proposed and experimentally examined. The impregnation apparatus consisted of a high pressure pump, two consecutive high pressure cylinders and auxiliary facilities. Polyester fiber was bound on cylindrical stainless steel net inside equilibrium cylinder and was impregnated with supercritical solution of PCM. PCMs, paraffin waxes and organic acids, were successfully impregnated into the polyester fiber even at temperature below it’s glass transition temperature(Tg), and the impregnated fibers showed high energy storage and release capacity around the melting point of respective PCMs.

Abstract: The surface of Li(Ni1/3Co1/3Mn1/3)O2 was modified with Al2O3 using aqueous alumina sol and the electrochemical properties of the coated oxide were measured and compared with both uncoated and Al-doped one. The alumina coated powder showed 185 mAh/g at first cycle, and 139 mAh/g after 50 cycles in the voltage range of 3.0~4.6 V at 1C rate. The initial discharge capacity of the coated powder was slightly lower than that of the alumina doped one, but the cycle stability of the coated was better than that of the doped.

Abstract: Preparation of Ag-Pd nanoparticles by the reduction of AgNO3 and PdCl2 with hydrazine in Igepal CO-520/cyclohexane reverse micelle solutions was studied. An analysis by transmission electron microscope and electron diffraction spectrum revealed that the resultant particles are silver-palladium. The average size of the synthesized nanoparticles slightly changed with increases in the molar ratio of water to Igepal CO 520. The average size of the synthesized nanoparticles was below 5
and they were broadly distributed.

Abstract: CoFe2O4 nanoparticles were prepared in ethylene glycol solution under mild temperature and pressure conditions by precipitation from metal nitrates. The average size of the synthesized CoFe2O4 nanoparticles was in the range of 5 to 10
, and they were narrowly distributed in the crystalline phase. Their magnetic property was of superparamagnetic character at room temperature. The effect of synthesis parameters is discussed such as the pH of starting solutions and reaction temperature.

Abstract: Nano sized ferrites, Sr1-xLaxFe12-yCoyO19 with improved magnetic properties have been successfully synthesized by a simple sol-gel method forming Fe2O3 and Co2O3 gel using propylene oxide as a gelation agent, followed by the addition of Sr2+ and La2+ ions. The magnetic behavior of Sr1-xLaxFe12-yCoyO19 powders annealed at and below 900°C showed that an increase of the annealing temperature resulted in the enhancement of the coercivity and the decrease of the saturation magnetization. Especially the highest values of the coercivity and the saturation magnetization of the ferrites with heat treatment were observed at temperature 150°C lower than those of the previously reported values. The highest observed values of the coercivity and the saturation magnetization of Sr0.6La0.4Fe11.8Co0.2O19 were 7,431 Oe and 52.3 emu/g at 900°C. The ferrite powders annealed at 700°C have a crystalline structure of M-ferrite and showed spherical particles shapes. The resulting spheres which were formed by the aggregation of nanoparticles with size 3~5 nm have diameter around 50 nm.