Advanced Materials Research Vols. 1044-1045

Abstract: This study investigated the feasibility of the electrochemical degradation of benzene (C₆H₆) in a NaCl electrolyte solution between 0.05 and 0.5 M under the temperature of 298 K and reaction concentration between 1.28×10^-5 and 1.28×10^-3 M with an applied potential of 3 V was conducted in this study to investigate the destruction of the C₆H₆ in the batch reactors using a Pt/XC-72 composite as a catalyst. Experimental results indicated that the optimal conditions in the reaction were developed as a NaCl solution with 0.1 M at pH of 1.0 under C₆H₆ concentration of 6.41×10^-4 M. The results reveal that electrochemical degradation of C₆H₆ in acidic medium is highly effective, while a maximum about 41% reduction at 120 min was achieved with Pt/XC-72 composite during the electrochemical degradation. In comparsion, the removal efficiency reached only 29% with the Pt electrode, showing the suitability of the Pt/XC-72 composites for electro-oxidation of C₆H₆. As a result, XC-72 carbon black materials played an important role in the decomposition of C₆H₆. Furthermore, the Pt/XC-72 composite used in this research has been developed as a potential catalyst for the application of C₆H₆ electro-oxidation.

Abstract: In order to eliminate cracks in the chromium coating, a novel method named flexible extrusion assisted chromium electroplating was proposed. The bright and crack-free chromium coatings were electrodeposited by using the perturbation and extrusion of hard and insulating particles. The prepared deposits were characterized by scanning electron microscope (SEM) and three-dimensional topography. The testing results showed that the surface was very smooth and there was no micro cracks in the coating. Micro hardness of the electrodeposited layer was also tested. It was confirmed that the chromium coating electrodeposited with rotating cathode in hard particles had high micro hardness as to 850HV and the micro hardness could be controlled by the process parameters. The rule of the micro hardness was concluded by analyzing current density and rotating speed. In addition the results of salt spray test and electrochemical polarization curve showed that the coating deposited by new method had higher corrosion resistance than that by traditional method.

Abstract: With the decline of pouring temperature in the range of 750°C~675°C, solidification curve was shifted to left primitively, and then gradually turned to right. Temperature of concretion nucleation and binary eutectic reaction was increased after a reduction, whereas the time was presented dynamically, both the minimum value which were obtained at 715 °Care 23.48s and 89.24s respectively. Growth time of crystal nucleation was extended after a slight decrease, the lowest point which was appeared at 715°C is 607.25s, time of binary eutectic reaction was varied as the cubic polynomial, the minimum value that emerged at 715°C is 228.39s. Solidification curve was changed as the exponential function, cooling rates ascended initially and then dropped andante, the peak point that achieved at 715°C is 5.93°C/min. The test results of microstructure shows that the content of primary and eutectic silicon with the plate-like and needle morphology, was increased primarily and then decreased with the decline of pouring temperature, however, the changing trend of grain size was shown as opposite, the minimum value which was obtained at 715°C is 534μm. It was also found from the results of grain size that with lower pouring and binary eutectic temperature, along with higher cooling rate and nucleation temperature, grain size was refined properly.

Abstract: γ-TiAl alloys are emerging as potential light-weight, high-temperature structural materials and possess wide capacities of engineering applications in aeronautics, space and automobile industries because of their low density, high specific strength and specific modulus, good oxidation-resistance and creep-resistance. Investment casting is introduced to complex TiAl net-shape or near net-shape components. In this research, ZrO₂ (CaO stabilized) was chosen as the face coat materials for the investment casting of TiAl alloys. The present study mainly focuses on the fabrication of ceramic shell mould for TiAl investment casting. Optimisation of reducing the stress in cast-mould system was carried out. The processing technology of the invented ceramic shell moulds was successfully verified in the investment casting of prototype TiAl parts. The interfacial reaction between TiAl alloys and ZrO₂ ceramic mould was analyzed using OM, SEM, EDS and XRD. The experimental results showed that, when the rotation speed is 200 rpm and 400 rpm, the thickness of reaction layer is about 5μm and 20μm, respectively.

Abstract: The glass-ceramics were produced via heat treatment from bulk base glass at the appropriate treatment temperatures provided by the differential thermal analysis (DTA) measurement. The effect of nucleation on crystallization kinetics has been explored. It is found that nucleation indeed decreased the activation energy of crystallization. X-ray diffraction (XRD) analysis demonstrated that the main crystalline phase was magnesium alumino-silicate (MgAl₂Si₃O₁₀), Scanning electron microscopy (SEM) morphology showed that the crystals were needle-like in all the samples.

Abstract: It is shown that as a result of electrolytic plasma carburization is released from the solid solution carbides dispersed particles based alloy components, i.e. hardening occurs. Found that after processing the surface of the alloy samples 40CrNiAl modified form reinforced layers whose thickness depends on the time, temperature and processing of components of the electrolyte.

Abstract: In order to investigate mechanics performance of rubber concrete steel composite beam, nonlinear analysis on four steel concrete composite beams with different amount of rubber has been carried out using finite element analysis software, and the influence of rubber concrete to mechanical properties of composite beam was explored. The results show that ductility, crack resistance of rubber concrete slab, shear capacity of shear connector for rubber concrete steel composite beam are improved significantly compared with ordinary steel concrete composite beams. Along with the increase of rubber content, the energy consumption of composite beams gradually increases, while the ultimate bearing capacity decreases with small amplitude. As a kind of green environmental protection material Rubber Aggregate concrete has the characteristics of good ductility, crack resistance is strong, energy consumption is obvious and good wear resistance.

Abstract: Semi-solid die casting instead of conventional casting was used to produce bearing cage, Model of semi-solid die-casting was established based on power cut-off (PLCO) model and ProCast 2008 to simulate the effects of processing parameters on deformation process, through orthogonal experiment and analysis of defects, the reasonable technological parameters for using A356 aluminum alloy to finish semi-solid die casting of bearing cage were obtained: the pouring temperature was580°C, the preheating temperature of the mould was 200°C, and the injection velocity was 20 mm/s.

Abstract: The precipitation of Ca₃(PO₄)₂ scale on pipe surfaces widely occurs in numerous industrial processes. For the control of Ca₃(PO₄)₂ scales, a novel environmentally friendly type of scale inhibitor Maleic anhydride (MA) - allypolyethoxy carboxylate (APEM) was synthesized. Structures of APEG, APEM, and MA-APEM were identified by FT-IR. MA-APEM possess excellent Ca₃(PO₄)₂ inhibition, approximately 96.7 % at threshold dosage of 6 mg/L, and it also have superior ability to iron (III) dispersion in solutions approximately 24.3 % in the presence of MA-APEM when the dosage exceeds 6 mg/L. Inhibitor of MA-APEM can be used safely in cooling water systems.

Abstract: Pitzer-Simonson-Clegg model was used to simulate the properties of the ternary system CaCl₂−KCl−H₂O. The Pitzer-Simonson-Clegg binary parameters and mixture parameters for the titled system at 348.15 K were obtained from the reliable experimental osmotic and solubility data. The solubility isotherms of the titled three ternary system were predicted by Pitzer-Simonson-Clegg model and compared with the available experimental data, the agreement is generally good. The solubility isotherms for the titled system CaCl₂−KCl−H₂O at 348. 15 K were predicted using Pitzer-Simonson-Clegg model.