Advanced Materials Research Vols. 602-604

Abstract: The paper introduced the process of slag-forming by using corundum slag in converter. The results showed that Al2O3 in corundum can reduce converter slag melting point, in advance of slag melting. Using this material, slagging process can be ahead of schedule for 30~40 seconds and the whole process of slag melting is good, without splashing, getting drying and lance-sticking. The consumption of metallic material and lime is reduced, and it shortens the melting period.

Abstract: The paper presents an analysis of the vibration damping properties of three-layer-connected biaxial weft knitted fabric (TBWK), which are constituted of carbon fibers as inserted yarns and polyester yarns as knitted yarns impregnated in an epoxy matrix with resin transfer molding (RTM) technique. Damping parameters were investigated using beam test specimens and an impulse technique. Several vibration parameters were varied to characterize the damping behavior in different amplitudes, natural frequencies and vibration modes. The results obtained show that the damping ratio of TBWK composites decreases with the increasing of fiber volume fraction in all the three vibration modes. The vibration test also indicates that the natural frequency of the TBWK composites increases with the increasing of fiber volume fraction (Vf) in all the three modes.

Abstract: In order to describe directly interphase properties of composite, force modulation of atomic force microscopy is adopted to study the cross-section of unidirectional carbon fiber/epoxy composites systematically. Research results indicate that in force modulation mode of AFM, relative stiffness of various phases distinct in distribution, which is described by probability histogram of relative stiffness. By comparison of probability histogram of relative stiffness nearby interphase of untreated and oxidation treated by ozone composites, the relative stiffness change oxidation treated one was more obviously to be found than the one untreated. Indirect show that obvious interphase formed by oxidation treatment. This method plays a valuable role in assessment of interphase strength of carbon fiber/epoxy, as well as in instruction composite production technology.

Abstract: Multiwall carbon nanotubes (MWCNTs) were embedded in cuprous oxide and copper to give ternary (Cu2O (Cu))/MWCNTs composites, Cu (CH3COO) 2•H2O and the treated MWCNTs were used as source precursor for producing composite particles by polyol method. Ethylene glycol (EG) was used as solvent and reducing agent. The products were characterized through scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The results have shown that the MWCNTs are embedded into the cuprous oxide and copper spheres homogeneously. At room temperature, the composite materials to the NOx have excellent gas sensitive response contrast to NH3, CO, H2. The concentration of NOx is 700 ppm, the maximum value of Cu2O/MWCNTs vs. the NOx gas sensor response sensitivity is 20.3 %, and gas sensor response has certain selectivity.

Abstract: In this study, first we prepared SBA-15 and sulfonate bearing SBA-15-SO3H.Then we modified the mesoporous silica with PEG to get SBA-15,SBA-15-SH,SBA-15-SO3H,SBA-15-PEG and SBA-15-SH-PEG.The samples were tested by FT-IR, nitrogen adsorption–desorption and TG. The tests showed that both SBA-15and SBA-15-SO3H we prepared had the typical properties of mesoporous materials. SBA-15-PEG and SBA-15-SH-PEG were successfully prepared.

Abstract: Cu-coated diamond particles in variable mass ratio of diamond and Cu are prepared by electroless plating process, then the coated particles are sintered by Spark Plasma Sintering (SPS) respectively. Diamond/Cu composites with high content of diamond(70vol%) are obtained eventually. The results indicate that not only coating diamond by copper electroless plating process could be used to obtain well-dispersed Diamond/Cu composites, but also effectively to improve the relative density of the sintered body, the relative density of the sintered body at 70vol% content of diamond is about 97.5%, as well as to obtain the composite with higher thermal conductivity. Thermal conductivity of the 70vol% Diamond-Cu composite reaches as high as 404 W/(m•K).

Abstract: Mn-doped black pigments CuMnxCr2-xO4(x=0, 0.05, 0.10, 0.15, 0.20 and 0.25) were synthesized by precursor coprecipitation method, and characterized by TG-DTA, XRD, FTIR and colorimetric analysis. The TG-DTA curves showed the crystal transition temperature was at about 800°C and mass loss ended at about 450°C. The infrared spectra displayed vibrations of spinel phase. XRD patterns displayed the characteristic peaks of the tetragonal phase spinel structure and proved that Mn substituted Cr in the spinel crystal lattice. L*a*b* analysis showed that all samples are black pigments with blue intensity, and Mn-doping could strengthen the black intensity and weaken the blue intensity of such black pigments.

Abstract: The composite laminates are produced by manual molding technology using two guide bar warp knitted fabrics of glass fiber as reinforcement and epoxy resin as matrix. The tensile properties of composites in the course, wale and diagonal directions are tested on the universal material testing machine. The influences of warp knitting stitch structures for mechanical performance of the composites are discussed. The results show that the tensile stress/strain curves of two guide bar warp knitted fabric reinforced composites were nonlinear. The tensile properties of composites possess obvious anisotropic characteristics. The tensile strengths and modulus of the warp knitting fabric composites depend on the yarn numbers bearing load along tensile direction, which are related to the stitches and structural parameters of warp knitted fabrics.

Abstract: A new type of laminated composite with B4C particle reinforced Al matrix composites as its inner layer and metal Al as outer layer was fabricated by powder metallurgy process. The effects of sintering time on the density and the mechanical properties of Al/B4C laminated composites were investigated. In the inner layer, Vicker’s hardness was enhanced with the addition of B4C. With the extension of sintering time from 2h to 4h at 300°C, aggregation of B4C particles reduced, while the density and Vicker’s hardness improved.

Abstract: Highly porous activated carbons were prepared through chemical activation of rice husk (RH). For the sake of optimization of the process, sixteen activated carbon samples were obtained from RH by means of carbonization in presence of H3PO4, and successive alkaline desilication, at the following conditions: activation time– 0.5 to 2 h, temperature– 300 to 600 ºС and Н3РО4/RH (wt/wt) impregnation ratio– 0.5 to 2. Samples were analyzed according to the data of thermal desorption of argon, low-temperature N2 adsorption using BET equation and BJH-calculation scheme, methylene blue (MB) adsorption studies, SEM, elemental analyses and yields. N2 BET surface area reached the value of 1690 m2/g; maximal MB adsorption capacity– 667 mg/g.