Advanced Materials Research Vols. 602-604

Abstract: Experiment of aluminum block erosion using organ-pipe nozzle was carried out in air. The erosion effects of water jet were used to evaluate the performance of organ-pipe nozzle. The experiment and corresponding data were used to analyze the effects of nozzle configuration, jet pressure, standoff distance. Results have shown that the organ-pipe water jets are much more effective in aluminum block erosion.

Abstract: A waterborne two-package inorganic high-temperature paint was prepared by using silica sol and methyltrimethoxysilane (MTMS) as the film-forming raw materials. The results showed the talc powder not only kept viscosity of paint stability but also increased construction time. The coating on the treated aluminum alloy was obtained through spraying and curing. The coating cured at 60 oC had higher density and breakdown temperature, good physicochemical properties, heat resistance property and electrical strength.

Abstract: Silicone paints were prepared by mixing as-synthesized silicone resin, pigments, fillers and other additives. The effects of the solvent, addition of pearlescent powder, addition of KH550, addition of butyl titanate and temperature on the performance of high-temperature-resistance silicon paints or coatings were studied. The results showed that the optimal coating was cured at room temperature and had no cracks after 10 times cold and hot alternation in the condition of 500oC~cold water. The pencil hardness and the adhesion of coating reached 3H and 1 level, respectively.

Abstract: In order to improve the defects of multi-layer Ni/(TiCP/Ni)/Ni composite coating and only TiB2 layer.TiB2-TiC composite coating is a good way. Because TiB2-TiC composite coating layer has well stability in high temperature conditions, high conductivity and TiB2-TiC composite coating layer has better wetting with the surface of copper electrodes in resistance spot welding of Zn-coated sheet steel. The TiB2-TiC composite coating electrodes were investigated by electronic balance, SEM, and microscope during different coating parameters. The best coating parameters include：coating voltage is 24V、coating capacitance is 3000μf、coating time about 2~3 minutes.

Abstract: The poly(pseudo)rotaxanes formed by β-CD and F127 was used as the template to prepare the mesoporous silica. The specific surface area, pore size distribution and pore volume of the mesoporous silica could be controlled by simply changing the poly(pseudo)rotaxanes forming time. A series of samples with different template forming time were prepared to investigate the various specific surface area and pore size of the mesoporous silica. The morphology, composition, specific surface area and pore size of the mesoporous silica particle were investigated by the scanning electron microscopy, Fourier transformation infrared spectroscope, and N2 adsorption–desorption measurement.

Abstract: This article deals with influence of the milling cutter tool’s geometry on tension in surface layer of workpiece. It describes, whether the tool brings the residual stress into the surface and its measurement by the magnetoelastic method based on the Barkhausen noise principle. The correct choice of the tool and cutting parameters has significant influence on surface layer of the component and extends so its lifetime and dependability. In this way we try to comply with permanent growing on the machine component.

Abstract: The surface of magnesium hydroxide (MH) was modified with stearic acid (SA). The modification mechanism was analyzed using a scanning electron microscope, thermogravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The results showed that an esterification reaction occurred between SA and MH. The modification effect was evaluated by activation index and oil absorbance rate. The results indicated that the optimum technological conditions were as follows: SA dosage was 1.25 wt. % at 70 °C for 10 min at a stirring rate of 2000 rpm. As a result, both dispersion and hydrophobicity of modified MH were remarkably improved.

Abstract: In this paper, nano-sized Al₂O₃ particles were prepared by mechanical milling, and Ni-P-Al2O3 composite coatings were plated on Q235 steel substrates, which plating solutions were containing different concentrations Al₂O₃ particles. The morphology, phase and particle size distribution of the as-prepared Al2O3 particles, and the properties of the coatings were investigated. The results show that, the morphology of the as-prepared Al₂O₃ particles were spherical and almost size under 100nm, the coatings were uniformly thickness and the Al₂O₃ particles were uniformly dispersed in the coatings, after heat treatment, the micro-hardness and wear resistance of the coatings were significantly improved, compared with the chemical method prepared Al₂O₃ particles, the mechanical method prepared Al₂O₃ particles had the same performance in improving the micro-hardness of the coatings.

Abstract: A hydroxylated silicon substrate was modified with 3-aminopropyltriethoxysilane (APTES) monolayer, followed by the surface initiated graft polymerization of the N-isopropylacrylamide (NIPAm). The microstructure of poly(N-isopropylacrylamide) (PNIPAm) coating was examined by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. And the results showed that about 50 nm thickness of PNIPAm coating grafted successfully.

Abstract: In this paper, WC-12Co coating are prepared by two HVOF systems. The biggest difference between these two systems is the fuel gas use. Morphology and mechanical properties of the coatings are analyzed. The results show that the coating sprayed with Airplane Kerosene fuel gas is denser and the WC particles distribute more even than that sprayed with propane fuel gas. And the WC particles melt more fully. The hardness, Young’s Modules and fracture toughness of the coating sprayed with Airplane Kerosene fuel gas is higher than that sprayed with propane fuel gas.