Advanced Materials Research Vols. 652-654

Abstract: In vitriolic electrolyte, DC power supply is used on 7075 aluminum alloy to have anodic oxidation treatment then let the oxidized samples have a treatment of electroless plating. Surface morphology of the coating and performance of corrosion wear are studied by means of scanning electron microscope (SEM) and friction and wear experimental machine. The results show that unsealed oxide coating have many holes and cracks, which are extremely badly-distributed; corrosion resistance of the oxide coatings which have the treatment of electroless plating have improved, having lower coefficient of friction and better performance of corrosion wear; besides; coefficient of friction of the samples in water is higher than that in salt water, its wear amount is less.

Abstract: Microcrystalline silicon thin films were deposited on glass substrates by VHF-PECVD varying the ratio of hydrogen dilution from 88% to 98%. The structural characteristics, deposition rate and photosensitivity of the films were investigated. With the improvement of the hydrogen dilution ratio, crystallization rate of the films had been improved which was much more stable than amorphous silicon that the films transmit from amorphous silicon to microcrystalline silicon. However the deposition rate had been reduced with the increase of the hydrogen dilution and the highest deposition rate was 0.43nm/s. The samples showed a downward trend of photosensitivity with optical and dark conductivity both decreasing first then increasing. Thus suitable hydrogen dilution ratio should be chosen according to the different needs in preparation of microcrystalline silicon film.

Abstract: Quantum dots ZnSe have been deposited through chemical bath deposition in thin films form. The nanoscal grain size of as-deposited and thermal treated ZnSe films have been investigated by X ray Diffraction. And optical band gap of those samples have been obtained from absorption spectrum. Both as-deposited and annealed films were with nanocryatlline grain smaller than the Bohr excitonic radius and showed blue shifts of bandgap in quantum size effects. The blue shifted optical bandgap versus grain size has been modeled theoretically.

Abstract: W-doped Vanadium oxide thin films were prepared on the substrates of glass and Si (100) by reactive magnetron sputtering after annealing in vacuum. The structure and morphology were characterized by X-ray diffractometer and atomic force microscopy(AFM), respectively. The results show that,when the oxygen volume percent (Po₂) increasing from 15% to 25%, the films on the Si(100) were vanadium oxides with high-valences. After vacuum annealing at 500°C for 2h, the major phase of W doped films on glass is VO₂. The surface roughness of the film increase for the longer time annealing.

Abstract: Ti-Al-Cu-N films with different Cu contents were synthesized on 1Cr11Ni2W2MoV stainless steel by DC magnetron sputtering. The microstructure, composition, microhardness and adhesion properties of the films were characterized by SEM/EDS, XRD, microhardness and scratch tests. The results show that a reduction of the grain size and an increase of hardness in Ti-Al-N films doped with1.04at% Cu were detected. Further increase the Cu content in the Ti-Al-N film, the grain size increases and become irregular, and the microhardness decreases. The adhesion property of Ti-Al-Cu-N films increased slightly comparing with Ti-Al-N film. The effects of Cu contents on the microstructure and adhesion properties of the Ti-Al-N films were discussed

Abstract: In this paper, the peeling strength between ultra-thin copper foil and carrier is improved by some rare earths used as additives during the formation of the stripping layer of H-G alloy. The effect of different rare earth and their different contents on the stripping property of ultra-thin copper foil with carrier when they are added in the H-G plating solution is investigated, and the influence of rare earth on the cathodic polarization curves and cyclic voltammetry curves of H-G alloy during its electrodeposition is analyzed too. Results show that rare earth elements of La, Sm, Y and Ce increase the peeling strength between ultra-thin copper foil and carrier to a certain extent and the peeling strength is increased from 0.13 kgf •cm-1 to the range of 0.16 ~ 0.20 kgf •cm-1. Different rare earth contents also have impact on the peel strength and surface property of ultra-thin copper foil with a carrier support, in which the optimum adding amount of La is 0.1 g •L-1. Electrochemical test results show that the addition of rare earths can reduce the degree of the plating solution’s polarization, accelerate the electrode reaction speed, increase the alloy reduction capacity, promote alloy’s co-deposition, and improve the bonding strength between alloy layer and substrate, thus the peeling strength between ultra-thin copper foil and carrier is enhanced.

Abstract: By using the mobile property of silicone oil during deposition, characteristic wedge-shaped chromium (Cr) films have been successfully prepared on glass substrates by direct current magnetron sputtering, and their mechanical instability is investigated. The experiment shows that a disordered network composed of straight-sided buckles, which is due to relief of large compressive stress after deposition, can be widely observed in these films. The size of the buckles increases linearly with the film thickness. In the vicinity of spreading front of the silicone oil, parallel straight-sided buckles perpendicular to the front and bifurcation morphologies can be observed. The influence of the edge effect on the buckle morphologies is also discussed in this paper.

Abstract: A viscous Nickel (Ni) solution was applied on amorphous Si films by spin coating and its effect on the crystallization of amorphous Si films was investigated with a two-step annealing process. The experimental results show that with the help of the two-step annealing, the crystallization of the film can take place at 500oC. At the same time, the crystalline fraction gets up to 79.4% after annealing at a high temperature of 520oC and the grain size of the polycrystalline Si films is approximately 200 nm.

Abstract: Dependence of the coating carbon layer configuration of cordierite monolith on reaction conditions in methane decomposition was investigated using N2 physisorption, SEM and TEM. The monolith surface area was increased after coating CNFs/CNTs. The microstructure of the coating layers in the coated monolith is dependent on the coating reaction conditions and the entanglement among CNFs/CNTs. High coating temperature and the presence of hydrogen in reaction gas for coating are advantageous to formation of CNTs. By comparison, coating layers of CNFs have better stability than that of CNTs in ultrasonic treatment.

Abstract: A dense hot-dipping Al-Zn-Si-Re-Mg coating was prepared on the surface of steel sheet. The microstructure and toughness of coating were investigated by SEM and Nano-indentation test. The polarization curve of coating was acquired in static 3.5 wt.% NaCl solution in air at 25°C. The results show that Re and Mg improve the corrosion resistance and toughness of Al-Zn-Si coating. The formation of passive film on surface of Al-Zn-Si-Re-Mg coating is easier than that of Al-Zn-Si coating. Re decreases the number of oxygen existed in the coating. Mg3Al2(SiO4)3 depresses the porosity of coating, which is a glassy compound and formed in hot-dipping process.