Applied Mechanics and Materials Vols. 130-134

Abstract: To improve the shortcoming in bag filter design in China (mainly used in purification of HF in alumina electrolytic flue gas), necessity of basic theoretical study on bag-filter used in purification of alumina electrolytic flue gas is analyzed. Four study aspects are proposed , which includs flow field optimization, influences of bag length and process parameter on forming dust layer, properties of the dust layer adsorbing hydrogen. Some primary study is done. This will provide a reference for engineering design and process operation.

Abstract: In this work we present the technology of preparing multilayer MgB₂ superconducting films via CVD method. The first layer of the MgB₂ superconducting film was obtained by two-step method: growthing the precursor boron film on a polycrystalline Al₂O₃ substrate first, then post annealing the film in magnesium ambient, thus we got the first layer of MgB₂ film. After that a pure boron film was deposited on the MgB₂ film , acting as the medium insulating layer, finally the second layer of the MgB₂ superconducting film was formed by in-situ growth, evaporated magnesium atoms and boron atoms that decomposed from diborane met near the substrate and generated the second layer of the MgB₂ superconducting film. The square resistance of the boron medium insulation layer is higher than 20 MΩ. The transition temperature of the both superconducting films was above 38 K, and the temperature for zero resistance is above 37 K. We found that different thickness of the B layer made different I-V curve between two superconducting films, which is very important for the use of Josephson junction. More meaningful results can be expected as the experiment goes on.

Abstract: This study proposes an approach to analysis the stresses distribution between the fitting roller and glass panel for a vertical panel attachment manufacture modulus under varied loading conditions as depicted in Figure 1. The fitted roller gabled with different rubber materials included Polchloroprene rubber (CR), nature robber (NR), and Polyurethane (PU), with the hardness 60, 70, 80 IRHD, respectively, The ANSYS and LS-DYNA software are adapted herein to simulate the contact stresses between fitted roller and glass panel. The external loading applied in rubber coated roller is from 1kg up to 5kg. The simulation results of the contact stresses, included pressure stresses and shear stresses, can understand how to achieve the uniform pressure situation between the fitted roller and the glass panel. Therefore, the compactness between the polarizer and the glass panel will reach perfect condition with no air bubbles left.

Abstract: Because of the situation that the disc cutter bearing seriously damaged in the cutting process, disc cutter structural parameters is optimized which mainly affect the force on the bearing. The disc cutter cutting edge angle, cutting edge width, transition arc radius and caulking ring width between the bearings are taken as design variables, and the minimum equivalent load on the bearing as the target, the optimization model is established. Genetic Algorithm (GA) is used in the mathematical model.Finally, the optimized results indicate that the equivalent load on the bearing reduces 21% compared with the actual structural parameters. So the optimization results effectively reduce the force on the bearing and extend the life cycle of disc cutter.

Abstract: For machining micro hole and micro cavity in ceramics, a manufacturing methods based on green machining have been systematically researched. The micro tool was prepared on-machine by micro electrical discharge machining (EDM). The tool size for micro hole drilling was determined based on extensive experimental results of the sintering shrinkage ratio and the gap caused by the removed ceramics particles between the tool and the workpiece to achieve the desired hole diameter. The tool path design was based on the tool size, the shrinkage ratio and the gap which is different from that in micro hole drilling. Micro holes with diameter of 100μm and micro cavities with upper surface size of 500μm×500μm was machined in ceramics successfully by this method. The final size error was controlled less than 2.25% in micro hole drilling and less than 2% in micro cavity generation.

Abstract: In conventional electrical discharge machining (EDM), the workpiece material is considered as homogenous material. When a micro feature is machined in alloy by micro EDM, microstructure of alloy may be of the same order as the micro feature. This may lead to the variation of machining performance of micro EDM. This paper demonstrates the influence of material microstructure on the machining performance by drilling micro holes within the crystal grain and on the boundary of TA0-1. Experimental results indicate that the average values of material removal rate, tool wear ratios and the discharge gaps on different locations are different because their material properties are different.

Abstract: The cooling stave longevity is the most important factor to affect the blast furnace life. In this paper the cooling stave model was built by use of software ANSYS. With boundary conditions of heat transfer of cooling stave fully taken into account, temperature fields of cooling stave made of different materials are analyzed. The analysis results showed the relationship between the different cooling stave materials and temperature field distribution of stave body. A general method of selecting cooling stave material and structure design for longevity design of cooling stave was developed.

Abstract: the reinforcement rib design is one of the key parts in entire bottle design. This paper presents the optimal design of reinforcement rib is based on the orthogonal test and finite element analysis, which is according to the finite element analysis results as its test data, with the target of the minimum stress, analyses the influence of each size of the reinforcement rib on the stress, obtain the optimal design proposal. The results show that the orthogonal experiment method can effectively distinguish different influence of various parameters on the stress, analyze the optimal design proposal, meanwhile, it can guide the bottle design in practical terms.

Abstract: The filling capability of forging die is the key to design forging die and it exerts an important influence to the quality and life of die. In response to the difficulty in filling of forging die, and taking forged Ti₃Al alloy as the research object, at the same height of reducing, strain rates during forming as the control objective, the finite element numerical simulation method was used to simulate the hot compression of Ti₃Al alloy with DEFORM-3D. This test simulated the process of hot compression, analysed the hot compression behavior of the stuff and discussed the effect of strain rates on the variety and distribution of stress and strain.

Abstract: High strength vanadium micro-alloyed steel with yield strength of 600MPa has been developed based on commercial 20MnSi steel bar. Experimental methods, such as OM, SEM and TEM, were used to study the experimental steels. Compared with 20MnSi, steel 20MnSiV boasts much finer microstructure, and large numbers of nanometer precipitates exist in the specimens of 20MnSiV. Analysis shows that strength of 20MnSiV dramatically increases through grain refinement strengthening and precipitation hardening of nanometer VCN particles.