In order to improve the precision of measurement, a new un-contact measurement system consisting of linear laser and single CCD camera was presented. For the system, technologies of pinhole imaging, laser plane constr...
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In order to improve the precision of measurement, a new un-contact measurement system consisting of linear laser and single CCD camera was presented. For the system, technologies of pinhole imaging, laser plane constraint mathematic model, and standard ladder-like block as a calibration of laser plane constraint are applied. The computer-controlled camera takes pictures continually and handles the pictures timely to extract the pixel coordinate of the laser line, and converts the 2D coordinate into 3D coordinate based on the model and rebuilds the object as point cloud to achieve auto 3D un-contact measurement. Experiments demonstrate that the precision of the system is 0.05 mm.
作者：
龚兴厚解孝林Department of Chemistry
Huazhong University of Science and Technology Wuhan 430074 China Department of Chemistry
Huazhong University of Science and Technology Wuhan 430074 ChinaState Key Laboratory of Plastic Forming Simulation and Die & Mould TechnologyHuazhong University of Science and Technology Wuhan 430074 China
The surfaces of the micron- sized HA particles were modified by in situ copolymerization of vinyl triethoxyl silane （VIES） and styrene （ St ）. Then, the modified HA particles were compounded with HIPS. The results...
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The surfaces of the micron- sized HA particles were modified by in situ copolymerization of vinyl triethoxyl silane （VIES） and styrene （ St ）. Then, the modified HA particles were compounded with HIPS. The results showed that the polystyrene （PS） macromolecules were grafted on the surfaces of HA particles during in situ copolymerization of VIES and St. Thereby, PS chains grafted on the HA surface enhance the compatibility between HA and HIPS, improve the dispersion of HA particles in HIPS matrix, and enhance the interfacial adhesion between HA and matrix. The stiffness, tensile strength and notch impact strength of HIPS/HA composites are improved at the same time. And there is a critical coating thickness of PS to the HA surface for the optimum mechani- cal properties of HIPS/HA composites.
A rapid manufacturing process for simple plastic moulds of zinc-based alloy, which combines LOM prototypes with silicone rubber moulds, transferred coating and precision casting technology, is developed in this paper....
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Fabrication process for anode supported planar PEN of intermediate temperature solid oxide fuel cell (SOFC) was introduced, in which tape casting and screen printing methods were used. Gd2O3 doped CeO2(GDC) powders we...
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Fabrication process for anode supported planar PEN of intermediate temperature solid oxide fuel cell (SOFC) was introduced, in which tape casting and screen printing methods were used. Gd2O3 doped CeO2(GDC) powders were prepared by solid reaction method. Anode tape was produced by tape casting. Electrolyte and cathode were produced by screen printing. The GDC powder's component, thermal expand coefficient, the porosity, density and microstructure of anode and electrolyte were investigated . It was shown that an bi-layer with dense thin electrolyte film and porous anode support and with good coherency of the electrolyte film to the anode could be realized after co-sintering the green tape at 1 350℃ by optimizing the power characteristics of the starting materials in the slurry.
Bulk amorphous Pd 82 Si 18 alloy with the largest diameter of 8 mm was prepared by water quenching the molten alloy with flux medium in a quartz tube. The calculation result indicates that the bulk Pd 82 Si 18 amorpho...
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Bulk amorphous Pd 82 Si 18 alloy with the largest diameter of 8 mm was prepared by water quenching the molten alloy with flux medium in a quartz tube. The calculation result indicates that the bulk Pd 82 Si 18 amorphous alloys have a low critical cooling rate ( R c) of 4.589 K/s or less. The experimental results show that purifying melt may improve glass forming ability(GFA) of undercooled melt, while liquid phase separation (LPS) of undercooled melt will decrease its GFA. There are some differences in crystallization experiments between bulk metallic glass and amorphous ribbons of Pd 82 Si 18 alloys. These include the numbers of exothermic peak, glass transition temperature T g, crystallization temperature T x, region of undercooling liquid (Δ T=T x- T g) respectively. The links of cooling rates of melt and crystallization of Pd 82 Si 18 amorphous alloys are explored.
Viscous pressure forming (VPF), a recently developed flexible dieforming process that is suitable for difficult to form material, can obtain the better stress states of sheet blank during forming process in manufactu...
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Viscous pressure forming (VPF), a recently developed flexible dieforming process that is suitable for difficult to form material, can obtain the better stress states of sheet blank during forming process in manufacturing complex shape parts. The process of manufacturing aluminum alloy ladder parts with VPF and solid metal punch was simulated by the FE software DEFORM. Under different blank holder pressure (BHP), the stress state, the strain state, the forming of small radius curved face and the distribution of thickness were analyzed. The simulation results show that, compared with solid metal punch forming, the sheet blank can flow into die cavity more easily with VPF due to the improvement of the stress states; the severe thickness reduction can be avoided, the sheet blank can contact the die perfectly and the parts have high dimensional accuracy.
Summary form only given, as follows. Plasma surfacing is an important enabling technology in high performance coating applications. Recently, it is being applied to rapid prototyping/tooling to reduce development time...
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Summary form only given, as follows. Plasma surfacing is an important enabling technology in high performance coating applications. Recently, it is being applied to rapid prototyping/tooling to reduce development time and manufacturing cost for the development of new product. In this technology, a plasma arc beam is used as thermal energy source, metal powders are preheated in plasma arc and deposited in melt pool on the base plate or deposited layer synchronously, with the movement of plasma gun and/or worktable controlled by CNC according to CAD slice model in computer, deposition layer grows gradually along z direction until the total part is fabricated. However, this technology is in its infancy, it is essential to understand clearly how process variables relate to deposit microstructure and properties for plasma deposition manufacturing (PDM) process control. In this article, the microstructure, mechanical properties and coating appearance for single surfacing and multiple surfacing under different parameters, such as plasma power, powder feedrate and scanning speed, etc., were studied in detail, and then a hybrid BP artificial neural network (ANN) and genetic algorithms (GAs) method which can overcome the shortcoming of BP neural network and obtain a global convergence result, was presented to optimize processing parameters. Using the optimized parameters, metal parts with complex shape and excellent mechanical properties and microstructure were fabricated successfully.
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