Abstract: The finite element software DYNAFORM was applied to simulate the whole tube hydroforming process. Two main failure types in the process of hydroforming are wrinkling and bursting. The strain distribution and thickness distribution at different process parameters were presented. Not only friction coefficient but also the effect of different matching of internal pressure and axial force was simulated and analyzed. In addition, the velocity of punch was considered too. The result has reference value for the variable cross-section tube hydroforming process research.
Abstract: The performance and wear mechanisms of Al-14%Si is analyzed for diamond coating cutters, the key engineering for effective machining of diamond coating cutters are put forward, practical bases of effective and rapid machining is provided for intractable metals as nonferrous metals or aluminium alloy. The cutting tools and programmed optimization of cutting speeds and feeds are analyzed. This paper summarised the key technology and application in high-speed NC manufacturing, and put forward some problems that should be taken care of in the high-speed NC manufacturing. It obtains good result in practical applications.
Abstract: The three-dimensional vibratory strengthening and polishing technology was used to strengthen and polish aeroengine blades with complicated surfaces. At first, the principle of the strengthening and polishing process was introduced, which combined strengthening process with polishing process. Then, the technological parameters influenced on the surface quality were investigated. The principal variables were the media hardness, the frequency and amplitude of the vibration, and duration of the vibratory strengthening and polishing. The optimum parameters were obtained. Experimental results revealed that, after strengthening and polishing, the surface roughness of aeroengine blades was reduced from Ra0.35-0.5μm to Ra0.1-0.12μm, and fatigue strength was increased by approximately 50%.
Abstract: Process equipment is essential for product manufacturing, especially for complex products such as aircraft and rocket. In order to improve the motion precision and automation level of process equipment, a new approach is brought forward. A data driven based process equipment automatic control system is introduced to control process equipment automatically according to process data. Fig. 1 in the full paper gives the system’s architecture. Based on analysis of the relationship among manufacturing processes, process plan information and process equipment, process equipment automatic control oriented information model was established. In order to realize automatic control of process equipment, a process equipment automatic control and management framework was established. The key technologies including motion control and motion detecting are discussed in detail. At last, the technology was applied to the design and manufacturing of a horizontal rocket rivet fixture. The application results show that this technology could remarkably increase the efficiency and accuracy of the manufacturing process.
Abstract: Hybrid microspheres with a polystyrene core coated with magnetite nanoparticles were prepared by two techniques. Firstly, monodispersed functional polystyrene latex particles were prepared by emulsion polymerization. In a general way chemical groups may be introduced through polymerizable surfactant or functional monomer. Magnetite acidic or alkaline sol was added in, then magnetite nanoparticles were absorbed onto latex particles by electrostatic attraction and core-shell composite particles were formed. Secondly, core-shell composite particles were prepared by miniemulsion polymerization. To modify the tendency of conglomeration of magnetite and increase the amount of magnetic particles onto the composite particles, silane coupling agent MPS was used as surface modification agent for magnetite. A series of different size and coating morphology magnetic hybrid particles were prepared through the adjustment of some experiment parameters. The obtained functional core-shell particles were characterized by FTIR, TEM, etc.
Abstract: In this paper, theoretical analysis is performed on the influence of multiple piezoelectric effects on piezoelectric coefficients. And a kind of classical piezoelectric ceramics was adopted to conduct the experimental validation. The experimental results of short-circuit boundary condition are obtained by the methods that a capacitor whose capacitance is much larger than that of the stack is parallel with PZT-5. Influence results are obtained through comparing them with open-circuit piezoelectric coefficient. Experimental result shows that multiple piezoelectric effects make piezoelectric coefficient of PZT-5 be altered by 18%.
Abstract: In order to rescue the problems of controlling laser bionic strengthening local stripe of mould surface quality, it is put forward thoughts about the laser bionic local melting stripe of mould surface quality detection based on acoustic signal. Analyzed with the relationship between defocusing distance and acoustic signal characteristic, laser bionic strengthening local stripe quality, the results show that acoustic signal is weakened with the increased absolute value of defocusing distance. As the defocusing distance is 0mm, the role of the laser is primarily ablation and the stripe quality is the worst; the function of laser on the surface materials is too weak to strengthen when the defocusing distance is -4mm; laser on target surface plays its role of strengthening, mainly owing to melting, with defocusing distance of +4mm. Overall tests show that, based on the quantitative detection of acoustic signal characteristic, it could inspect and control the quality of strengthening stripe, and it will realize the overall control of laser bionic strengthening mould surface quality with guiding significance.
Abstract: Laser transmission welding (LTW) is a new technology for joining plastic components, involves a laser beam passing through a laser-transmitting part being absorbed by a laser-absorbing part at the weld interface. To form a strong bond, it is important that the weld interface be exposed to sufﬁcient heat to melt the polymer without degrading it. This paper investigates the quality of PMMA (Polymethyl Methacrylate) laser transmission welding by using YAG (1.06um) laser. Using the orthogonal experiment method, the specimens under different parameters have been studied. In order to evaluate the mechanical resistance of the welded joint, surface proﬁlometry and metallographic microscopy were employed. It was shown that welding quality was significantly influenced by speed, power, and welding spot size. We summarized the influence of various factors, and eventually obtained the experimental results under different experimental parameters.
Abstract: Fluidity of ZL101 aluminium alloys in the low-pressure lost foam casting (LP-LFC) process has been investigated by altering various temperature variables. The experimental results indicate that the LP-LFC process had fine fluidity, and the pouring temperature was lower than conventional lost foam casting. The effect of the metal temperature on the fluidity is marginal in the LP-LFC process. Excessive pouring temperature not only aggrandizes energy consumption but also deteriorates porosity defect. The success of casting cooling fin demonstrates the advantages of LP-EPC process in producing high-complicated castings.
Abstract: Regrinding of wasted cutting tools can recycle resources and decrease manufacturing costs. Influence of relative tool sharpness and tool cutting edge angle on tool edge radius were analyzed. Cutting force and cutting temperature were simulated with FEM on different edge radius. Edge preparation experiments were carried out though an abrasive nylon brushing method. The results show that RTS and cutting edge angle have influence on edge radius. Small edge radius might result in small cutting forces and lower average temperatures, could maintain the cutting state between tool and workpiece. The cutting edge defects can be eliminated through edge preparation, and a smooth cutting edge can be obtained. Cutting tool life will be improved through proper edge design and edge preparation.