Advanced Materials Research Vols. 150-151

Abstract: Cracks is frequently generated in crown gear of main reducer of big modulus used in heavy duty truck after carbonizing and quenching. The heat treatment process and the pre-heat treatment before carbonizing, the carbonization process parameter and the quench treatment, all of which influence the component, structure and stress of the gear. In this paper, metallographic examination of the gear was taken after heat treatment with different process parameter, and the reasons that caused cracks in the 22CrMoH steel crown gear used in heavy duty truck after heat treatment was discussed. And strategies and methods are proposed as well.

Abstract: The textured thin films of fluorine-doped tin oxide (FTO) were prepared onto preheated glass substrates by a spray pyrolysis technique, using dehydrate stannous chloride (SnCl2:2H2O) and ammonium fluoride (NH4F) mixed with alcohol, as precursor. The haze and properties of the films heat treated at different temperatures from 400 to 550 were characterized by X-ray diffraction (XRD), 3D Digitale Mikroskop, Atomic Force Microscopy, UV-Vis spectrometer, sphere photometer and four-probe instrument. The results show that, with the increase of the substrate temperature, XRD peaks become sharper, the grain sizes grow up rapidly, and the crystal structure is improved gradually; the surface topography become like the islands and the haze achieves 16.47%. The lowest sheet resistance of the films is 9.7Ω/□. The effect of the substrate temperature on the haze, electric property and optical transmittance of the FTO films has been discussed in detail. The results show textured SnO2:F thin film deposited onto preheated glass substrates by a spray pyrolysis technique would be used as transparent electrode in amorphous silicon(a-Si) solar cells due to its excellent properties.

Abstract: A novel phenolic resin suitable for hot-melt impregnation process was developed through copolymerization. The curing reactivity, gel properties and viscosity of the resin were tested to evaluate the resin reaction process. A prepreg of this resin and glass fabrics was developed with hot-melt process. The cured phenolic prepreg laminates havebalanced mechanical properties. It can be used to manufacture interior structures for airplanes and high-speed trains or other applications with flame retard requirement.

Abstract: The components in slurry pump suffer serious corrosion and abrasion in the phosphorus fertilizer manufacturing process because they undergo corrosion of H3PO4 medium and impact of particles at the same time. Presently, High chromium cast irons are often used to produce the components in slurry pump. In order to reveal the corrosive law, the corrosion properties of high chromium cast iron with 26wt.%Cr content (Cr26) were tested under different H3PO4 medium concentration conditions. Using back-propagation (BP) neural network, the non-linear relationship between the corrosion weight losses (W) and H3PO4 concentration, corrosion time (C, t) is established on the base of the dealing with experimental data. The results show that the well-trained BP neural network can predict the wear weight loss precisely according to H3PO4 concentration and corrosion time. The prediction results reveal that corrosion weight loss rises linearly with increasing corrosion time. The H3PO4 concentration has obvious effect on corrosion property. When H3PO4 concentration is lower than about 0.5mol/L, high chromium cast iron has well resistance to H3PO4 corrosion. However, the corrosion resistance of high chromium cast iron rapidly decreases when the H3PO4 concentration exceed about 0.8 mol/L. It is suggest the high chromium cast iron be used under the condition of H3PO4 concentration of lower 0.8 mol/L.

Abstract: Influence of borate eluent pH value and competition eluant on regeneration of the used IMAC-Cu proteinchip is investigated by SEM and SELDI-TOF-MS proteinchip detection system. The results show that proteins are easier to be removed from the used proteinchip surface with the decreasing of borate eluent pH value, but its destruction to the chemical structure of the proteinchip also grows in intensity. The elution effect of protein on IMAC-Cu proteinchip can be significantly enhanced when the competition eluant Gly or EDTA is added to borate eluate. However, comparing with Gly, EDTA as competition eluant has generation effect. The absorption protein quantity and type of the regenerated IMAC-Cu proteinchip by the pH 8 borate eluent added 0.02mol/L EDTA for 72h is very similar to the fresh chip after absorbing same serum of cancer patients.

Abstract: The three composite boards which were made of continuous basalt fiber (CBF) and polypropylene fiber (PP) in different fiber ratios were researched on this paper. The manufacturing forming process included blending, carding, web formation, laminating and compression molding orderly. The tension and bending properties were investigated experimentally, and then dual variance analysis was used to show the significant difference of the mechanical property in the transverse and longitudinal orientation as well the appreciable impact of different fiber ratios to the mechanical property. The results show that the difference of the tension and blending strength in the same direction, among composite boards in different fiber proportions, is about 1~10Mpa; the difference in the same fiber proportion, between transverse and longitudinal, vary within a wide range from 10Mpa to 30Mpa. The results of variance analysis have also proved the conclusion, the difference between transverse and longitudinal is more significant than the difference among different fiber proportions. In the similar study, the significance hadn’t been seen sufficiently, so this paper provides reference to the actual application of the composite board.

Abstract: The object of this study is to investigate the sintering mechanism of lightweight ceramic by different sintering temperature. The raw materials were sewage sludge and fly-ash, and clay was added as cementing agents (by ratio of 50wt% in each sample). The raw materials were mixed and pressed into raw pellets. After drying and preheating treatment, the raw pellets were sintered at temperatures ranging from 1050 to 1150 , in 25 increments for 10min. The physical properties (bulk density, grain density, water absorption and rate of expansion) were the indexes used to determine the technical parameters for the preparation of lightweight ceramic pellets and investigate the sintering mechanism of bloating. The results suggested that temperature was the key control factor of sintering process, and 1150 was the starting point of bloating reaction. Observation of the microstructure by SEM indicated that a higher flux content in the raw materials could lower the melt point during sintering process.

Abstract: The NiO thin film was deposited on the stainless and single crystal Si substrate by the dip-coating combined with thermal treatment. Thermal decomposition behavior of gel precursor, the structure, morphology and electrochemical properties of NiO thin film were characterized by TG-DSC, XRD, SEM, cyclic voltammetry and the constant current charge/discharge technology. The results show that the gel completely decomposes at 430°C to form the nanocrystalline NiO gradually and its crystal structure becomes integrity and particles largen as the increasing of the sintering temperature. The NiO film sintered at 600°C exhibits smooth surface, uniform, compact and free of cracks. At the cut-off voltage of 0-3V and the current density of 0.01 mA/cm2, its first discharge special capacity is 1285mAh/g and remains 650mAh/g after 300 cycles. In addition, the special capacity of NiO thin film still remains above 300mAh/g at large current density of 0.04 mAh/g after 300cycles exhibiting excellent electrochemical performance.

Abstract: To enhance the wear resistance of molybdenum alloys, Mo-based composites reinforced by Al2O3 ceramic particles were developed. Using Al(NO3)3 aqueous solution and MoO3 as raw materials, the Molybdenum powders mixed with Al2O3 particles were prepared by liquid-solid incorporation, drying, pyrolysis of Al(NO3)3 and deoxidation of MoO3 by H2. And then the Mo-based composites with 3-10vol.% Alumina were prepared by compaction and sintering at 1840°C. The morphology of the Molybdenum powder and microstructure of the composites were analyzed by SEM and XRD. The micro-hardness, density and wear property of composites were researched. The results showed that α-Al2O3 ceramic particles and Molybdenum matrix compose the composites. With the increase of Alumina content, the molybdenum powders become fine and rule, the grains of composites become fine, the microhardness of Molybdenum matrix increases, and the density first increases and then decreases. The friction coefficient of composite is scarcely affected by the alumina content. While the wear weight of the composite decrease with the increase of Alumina content. There are obvious plow furrow and abrasive dust on the worn surface, showing the abrasive wear characterization.

Abstract: Being torn apart due to the slit initially cut on coated fabrics is the typical form of failure under mono-axial tensile load. The mono-axial centre slit tear test of coated fabrics was conducted to investigate the influences of slit orientation and initial slit length on the tearing strengths and corresponding tearing elongation. Given a fixed initial slit length, the tear strength and displacement both decreased with the increase of angle between the slit and the load direction. The tear strengths and corresponding elongations increased with the reduction of the slit lengths, when the slits inclining 30 ° and 60° to the mono-axial tensile load direction, respectively. However, the influence of slit lengths was insignificant when the slits were perpendicular or parallel to the load directions.