Advanced Materials Research Vols. 631-632

Abstract: With the rapid penetration of information technology in various fields, CAD/CAM/CAE technology has been widely used to fundamentally change the traditional design, production, organizational models, it also has a very important significance to promote the technological transformation of existing enterprises, bring the whole structural change of the night, develop the new technologies and the promotion of economic growth. The paper uses the blades of steam turbine as an example, combined with the finite element analysis method to study the whole cutting process, the whole process was simulated and the results of error were had analysis and optimization.

Abstract: With the development of parts processing technology, the machinery industry has also brought about great development. In this paper, using the computer technology carries out research on the surface machining process physical simulation, through the research on kinetic equation characteristics of surface parts in the cutting process, to establish simulation model. Then, according to the computer system to carry out parameter optimized, it can get the need of parts cutting’s perfect surface equation, speed, cutting time and other parameters. At the same time, through the simulation optimization system design, it can provide parameters basis for precise control of curved surface parts cutting process.

Abstract: Through the establishment of ANSYS tundish steel liquid flow finite element model analysis of finite element method in simulating the flow field in tundish for applications. comparison with and without flow control device of liquid steel in tundish flow characteristics the results have guiding significance for practical production.

Abstract: Cavitation erosion behavior of 17-4PH steel used for large turbine blades and laser surface melting layer were investigated in simulated seawater 3.5%NaCl solution through an ultrasonic vibration system. The microstructure and the eroded surface and cross-section morphology were observed by SEM and OM, then the results were compared and analyzed. The results showed that the microstructures of 17-4PH stainless steels consist of martensitic matrix, ferrite and residual austenite. Compared with 17-4PH substrate, it found the microstructure of laser surface melting treatment became dense and homogenous, the microhardness increased 80HV. During cavitation test, the cavitation incubation period of laser surface melting sample raised 1 time than 17-4PH steel, and enhanced its cavitation resistance through fine grain strengthening.

Abstract: Tests were performed on mechanical property and microstructure of joints on cold-formed high frequency induction welded (HFIW) pipes. The welding surface energy (WSE) is proposed to evaluate the combined effect of technological parameters including the welding speed, input power and wall-thickness. The optimum production technology was obtained. The Widmanstätten microstructure and coarse grains were observed in the overheated zone. The width of the heat-affected zone (HAZ) is proportional to the WSE. With increase of the WSE, the reversed V-shape was formed by the mean bend angle. The optimum WSE decreases with decreasing the opening angle. Rather than the standard tensile test, the cold-bending test is suitable for evaluating effect of technology on quality of joints on cold-formed HFIW pipe.

Abstract: In this study, cold reduction process of the tubular metal is applied to manufacture the drive shaft for the rear wheel drive system. With this method during forming process, chip forming such as hobbing and broaching method is not involved. The manufacturing process is as follows; the tube which the sheet is formed and welded to by roll forming machine, is mounted on a suitable mandrel. This mandrel has an external toothing which corresponds to internal toothing of the final product. During axial moving and rotating of the workpiece, forming operation is carried out in lengthwise direction of the toothing. This forming rolls is positioned on the roll head and have a rolling axis vertical with the one of a mandrel. The total forming load needed in the cold reduction process is separated into numerous forming steps along the entire cylindrical length of the zone to be formed. In the process of cold forming on the profiled mandrel during the impact forming operation, material is pushed into depression of toothing of a mandrel mainly in a radial direction. Finally splines can be generated on the surface of components and overall elongated. If the process parameter such as the length of forming per 1rotation of 1roll is not optimized, the impact force from the rolls of the forming process causes geometrical defects. So the optimal parameters such as feeding and rotating speed of workpiece and the forming length should be properly determined. And the effects of the weld line positioning on the formability of the forming process is analyzed to minimize the generation of the defects such as crack on the surface of splined zone.

Abstract: Aluminum alloy-aluminum-steel cladding plates were manufactured by explosive welding. Microstructures of the cladding plates were observed and the interface bonding properties were tested. Aluminum alloy-aluminum-steel transition joints were produced by welding the explosive cladding plates. The bonding interface configuration and property were investigated and tested after welding. The effects of welding technology on the interface bonding properties were discussed. The results showed that metallurgical behavior has been occurred at the bonding interfaces between aluminum alloy and aluminum and aluminum and steel. Regular sine waves have appeared on the bonding interface between aluminum alloy and aluminum. However, the bonding interfaces between aluminum and steel present line-shape. The shear strength and separate strength of the cladding plates were much higher than the standard strength. After being welded, the configuration of the bonding interface has no marked change. The strength of the bonding interface decrease a little. The welding technology had no remarkable effect on the bonding interface of the aluminum alloy-aluminum-steel cladding plates.

Abstract: Antireflection of silicon surface is one key technology for manufacture of efficient solar cells. The noble metal assisted chemical etching Si wafer can quickly produce a black Si surface with a high porosity in HF-H₂O₂-H₂O solution at room temperature. The pores formed are straight and vertical to the surface of Si. The porous Si surface exhibits a reflectivity of 2 % in the range of 200-1000 nm, which shows that this process is beneficial to improve the conversion efficiency and to decrease the cost of Si solar cells.

Abstract: It describes the geometrical parameters of the joint surface in the fractured rock, through two parameters, i.e. JRC (Joint Roughness Coefficient) and JMC (Joint Matching Coefficient). Following these coefficients, the geometry of the surface has been measured exactly. Meanwhile, the rock deformation and seepage characteristics have been mainly defined by the joint surface, so the influence of JRC and JMC on the aperture width and the seepage properties have been deeply studied. Based on the cubic law of the flow water, the two parameters incorporated into the law and the permeability of the fractured rock has been obtained.

Abstract: According to the acidizing practice of water injection well in recent years, this paper analyzes and summarizes the damage and solution of sandstone reservoir before and during the process of acidification, and secondary damage countermeasures are putted forward to prevent acid rock reaction. Preventing new precipitation forming during the process of acidification is an important aspect to improve the acidizing effect. And through the indoor experiments and field tests in oilfield, it is obvious that the reservoir damage is very complex, generality and difference. Acidification process has very strong pertinence, so it is very important to analyze and understand the reservoir geological characteristics, productivity, dynamic and static production material. Only making the damage of reservoir clear, the appropriate solutions, which can improve the acidizing effect, achieve the purpose of acidification and meet the needs of actual production, can be used. And the solutions of different damages are analyzed and presented.