Advanced Materials Research Vols. 472-475

Abstract: The conformation of volume free energy is very important for microstructure simulation with phase-field method. However, the conformation of volume free energy is still correspondingly simple and ideal at present. In this paper, a new conformation method of free energy is mentioned. Free energy of each phase at appointed states is calculated by Thermo-Calc software. Free energy of each phase is fitted by multiple-point function according to sub- regular solution model. It is obtained that the free energy data and phase graph data of α phase, θ phase and L phase in the extension, temperature (791-841) K and component (0-35)Cu(at.%) with Al-Cu eutectic alloy.

Abstract: Based on models of a porous electrode, a more accurate lattice Boltzmann model for simulating the performance of a solid oxide fuel cell (SOFC) is proposed. Results show good agreement between simulated and measured data. The accuracy of concentration over potential prediction is crucial for low reactant concentrations. The addition of a small amount of air to the fuel yields fully stable performance without measurable carbon deposits detected on the catalyst layer or the fuel cell. Cell performance increases with the temperature. As a first test of the model, a benchmark problem regarding the performance of an internal reforming solid oxide fuel cell (IR-SOFC) is investigated. When the catalyst activity decreases, the rate of methane conversion decreases near the reactor

Abstract: In order to solve the problems of environment pollution and human resource consumption in traditional wet cleaning process in auto lamps production, a high-voltage Plasma Cleaning Technology (PCT) is presented in this paper. The plasma cleaning system, high voltage AC power and control strategy are realized to develop the plasma cleaning industrial equipment which is used for surface cleaning and activation to promote adhesion between basement and base painting of auto lamps, and the configuration and operation rules are analyzed in detail. According to the established gas discharge model, the PID fuzzy control strategy is achieved to complete automatic control of technology process. The experimental parameters, such as electrical field, gas pressure, and some random factors, are discussed in terms of the curves from practical data. The results show that this design and implementation are feasible in industrial production. After the treatment of PCT to the surface of auto lamps within the automatic equipment, the adhesion between the base material and base painting films is enhanced to a great extent, and the quality and passing rate of production has been greatly improved.

Abstract: the coulped neutronics and thermo-hydraulics model for supercritical water-cooled reactor (SCWR) is developed by internal coupling method. It is based on the two group neutron diffusion equations and the one-dimensional junction thermal analysis mode, in which the cross sections used for SCWR are generated by Dragon tool. Compared with the calculation results based on the non-coupling calculation model, the steady state characteristics under coupling calculation condition are detailed analyzed by considering parameters feedback at each axial node. The results show that, as coupled model is chosen its axial power distribution would give an obvious deviation from the cosine function that used for non-coupled model. Although the cladding temperature at most of the axial nodes rises with a shifted power peak, the maximum cladding temperature is finally decreased. For the above coupling condition, the maximum cladding temperature would appear at the external assemblies with lower coolant temperature but not at inner assemblies with higher coolant temperature. As the detailed description for coupling characteristics of supercritical water-cooled reactor is given, a certain theory reference for its system safety could be provided.

Abstract: As a teaching model, "project-based teaching" method in the teaching of programming language courses has a very important & practical significance. Especially for higher vocational colleges students to develop practical skills is a top priority, "project-based teaching" can do this. In this paper, C51 programming and development based on micro-controller theory and application has illustrated the principles of project teaching means and strategies for project selection, and made a selection of teaching content to be highlighted based on real objects of material and social needs for the purpose of the base principles. In additional, projects being well selected for teaching methods can greatly raise their overall professional and practical abilities and also as possible as develop the potential and foster creativity.

Abstract: Cr coatings were deposited on AISI H13 steel substrates by means of electrospark deposition (ESD). The coatings were characterized in terms of their microstructure, hardness, friction and wear behavior and high-temperature oxidation resistance. Micro-indentation and tribometer testers were employed to measure the mechanical properties of Cr coatings and AISI H13 steel. The results showed that the hardness of the coatings ranged from 600 to 660 HV, with a higher value than that of AISI H13 steel (510 HV). The coefficient of steady-state friction of the coatings against 45-carbon-steel balls ranged from 0.23 to 0.27, with a lower value than that of AISI H13 steel (0.62-0.68). The isothermal oxidation behavior of the coatings at 850°Cwas studied in comparison with AISI H13 steel substrates. The results indicated that Cr coatings substantially increase the high-temperature oxidation resistance of AISI H13 steel and the oxidation process was retarded mainly by the presence of a Cr2O3 oxide scale on the coatings at 850°C for 100 hours.

Abstract: The secondary processing of WPC (wood-plastic composite, WPC) is a necessary method to make its productions more beautiful while it is applied in furniture, sanitary location, bathroom and other fields. Although there is widespread availability of WPC abroad, such as building, municipal installations, packing and other occasions, but on the contrary, there is little application in our country. As a substitutes of wood, WPC has many excellent performances such as light weight, high rigid, water resistance, insect resistance, acid and alkali resistance etc, it can be nailed, drilled, planed, sawed, agglutinated and painted like lumber. Furthermore, it can be extruded as thermoplastics, and decorated by printing or spraying. In this research, problems of WPC popularization in domestic furniture market are clarified by analyzing the material performances and consumer mentality.

Abstract: TiC reinforced Fe-based composite coating with 10% and 20% TiC particle were prepared on the surface of substrate Q235 steel by plasma cladding, respectively. The microstructure and formation mechanism of cladding layer were carefully investigated by SEM, EDS and XRD. The results show that metallurgical combination is achieved between coating and substrate, the microstructure of composite coating is composed of dendrite α-Fe, interdendritic eutectic structure (α-Fe, Cr23C6 and CrB) and added TiC particles, and microstructure refinement with the increase of TiC particles content. TiC particles react with Fe-based alloy and part of TiC particles dissolve into coating. The hardness of composite coating has a relationship with TiC particles content and TiC particles distribution, and hardness increase with the increase of TiC particles content. The maximum value of composite coating hardness is 545 HV0.2 and 719 HV0.2, respectively. The major strengthening mechanism is fine-grain strengthening, solid solution strengthening and dispersion strengthening.

Abstract: Through the chemical analysis, mechanical properties tests, metallographic analysis, fracture and fatigue tests on 22Cr2Ni4MoVA steel cut from deactivated crystal kettle which had been used for 9 years, we obtained a variety of mechanical properties data, and confirmed that the yield strength and ultimate strength of 22Cr2Ni4MoVA steel were basically unchanged in crystal growing environment, but the impact energy, sectional shrinkage and fracture toughness that reflect material toughness were significantly descend, and there existed serious embrittlement and creep deformation. The failure mode of 22Cr2Ni4MoVA steel was brittle fracture under the co-activation of creep fatigue and corrosion. The decline of creep deformation and endurance limit at high temperature played a guiding role; fatigue and corrosion played an initiative attacking role; and temper brittleness acted in degenerating, losing immunity and increasing crack sensitivity; while the stress concentration on kettle bottom and alkaline solution with high concentration provided a breeding ground for failure.

Abstract: The microstructures and properties of Al2O3-TiB2 composite coating on the surface of the aluminum alloy by reactive spraying was studied. The influences of mechanical alloying and spraying temperature on the phase constituent and microstructure of the composite were analyzed by X-ray diffractometry(XRD) and scanning electron microscopy(SEM). The results indicate that Al2O3-TiB2 composite coating is obtained by plasma spraying using milled powder of Al，TiO2，B2O and B2O3. The coating possesses high microhardness of 1300 HV0.1.