Abstract: A study of the fracture phenomenon of zirconia-toughened alumina (ZTA) ceramics was carried. It analyzes the mechanisms of crack propagation of ZTA ceramics, and constructs fracture experiments of ZTA ceramics, so the propagation behavior on fracture in ZTA ceramics was investigated according to the experiment. By contrast, intercrystalline fracture happed in V-shaped groove of ceramic specimen under normal load without ultrasonic vibration during ceramic fracture, and transcrystalline fracture happed in V-shaped groove of ceramic specimen under normal load with ultrasonic vibration during ceramic fracture. Furthermore, the loading force of ceramic specimen under normal load with ultrasonic vibration is smaller than that under normal load without ultrasonic vibration all other conditions being equal. The results of fracture experiment prove that ultrasonic vibration assisted is good for the fracture of ceramic specimen, and it also proves that ultrasonic vibration assisted grinding may raise the working efficiency and improve surface integrity of ceramics from the standpoint of the fracture.
Abstract: Fluid magnetic abrasivetool(FMA) is one kind of latest finishing abrasivetool which is a sort of suspended fluid composed by magnetic particles, nonmagnetic abrasive particles, surfactants in a non-magnetizable carrier liquid. After a period of working time, the performance-life of the abrasivetool ended because of the cutting- blade of the abrasives particles being passive. While the most costly component- the magnetic particles (carbonyl iron particles) can be reused. This paper has made up two recovery flows to separated carbonyl iron particles from others.
Abstract: Conventional electrical discharge truing/dressing(EDD) technology shows important limitations that it is only applicable to electrical grinding wheels. This paper proposed novel EDD technology which could truing/dressing nonelectrical superabrasive grinding wheels such as resin-bonded diamond wheel and vitrified CBN wheel by means of covering electrical material on the surface of wheel. The principle of removing non-electrical bond during dressing process is illustrated. The results of electrical discharge dressing under different discharge current（ie）were compared. Experiments results indicate that the EDD method proposed in this paper has been applicable to nonelectrical bond wheels. In addition, discharge current has direct influence on the wheel surface topography and the performance of diamond grain.
Abstract: Aiming at the independent geometric reference models of IGES surfaces for housing-type components, basing on the Pro/E, authors proposed the method of using the "exterior copy geometry" technology to extract references for surface reconstruction. The top down design ideas are adopted to break down original complex model into several components. After defining the modeling datum and father-son relationship, copy geometry is applied to reconstruct each component. Then all the part models are assembled by "exterior copy geometry" technology in the way of coordinate system superposition. And finally a 3D modeling of complex surface part is reconstructed. The No.10 coupler in CHR3 train is taken as a case study. Extracting geometry reference data from IGES model, without any parametric features, then these data are used to do parametric modeling in Pro/E in order to make them support variability design. Cooperating Pro/E with Imageware, quality of surface reconstructed is analyzed and evaluated. The above method provides an efficient solution for complex parts parameterization modeling and evaluation.
Abstract: As a kind of precise surface finishing technology, magnetic abrasive finishing has wide application, low cost, high efficiency, good effects, and other advantages. Magnetic induction intensity is one main parameter affecting finishing effect and efficiency of magnetic abrasive finishing. Saturation magnetic induction intensity for different magnetic abrasives is defined through test device designed by ourselves. Affecting rules of saturation magnetic induction intensity is discussed by experiments, which provide basis for parameters selection and practical application of magnetic abrasive finishing.
Abstract: Because of the industrial robot’s advantages and characteristics of degree of freedom, it is broadly applied in mold and die of curved surfaces polishing. But its excessive degree of freedom also brings great difficulties in programming for there is CAD/CAM software can do it well. By analyzing the ISO NC code and robot’s programming criterion, this paper develops off-line programming software for industrial robots in free-form surfaces polishing.
Abstract: Rudder actuator loading test system is the torque load simulation device of flight vehicles. An electric loading scheme of a PWM drive torque motor is proposed in this paper. Then the box-shaped structure of the loading system is designed, the performance of the loading system is improved for the high machining and assembly shaft system precision by adopting this structure.
Abstract: Comparing with conventional WEDM in emulsion, dry finishing of high-speed WEDM (HS-WEDM) has advantages such as higher material removal rate, better surface roughness and straightness. Authors have presented a new procedure as gas-liquid combined multiple cut, in which roughing is processed in dielectric liquid, and semi-finishing is in liquid or gas, while finishing is in gas. For better understanding the effect of machining parameters on surface roughness and cutting speed in dry finishing, a L25(56) Design was implemented. The analysis of variance shows that the effect of pulse duration on surface roughness is of high significance, and peak current is of significance respectively, and the effect of no load worktable feed on cutting speed is high significant.
Abstract: Aim at complex function Fourier transform, the complex index expanded form have been discussed in this paper. The paper indicates that the periodical complex function can be used to describe the motion trace of a point in complex plane. Then the engineering application of complex signal frequency spectrum analysis has been discussed in this paper. This technique has been applied to the fields of mechanical engineering and some innovative achievements have been obtained, such as the establishment of new rotation accuracy theory, the suggestion of spectrum analysis for mechanism synthesis and the invention of polar locus generator. This paper also points out some misunderstandings that due to oversight of complex signal in the academia of signal analysis.
Abstract: The effect of extrusion process on the quality of AZ31 magnesium extrudate was performed, by data mining from 3DFEM simulation and Rough Set Theory(RST). The weight of the effect of processing parameters and die structures can be obtained to predict the product quality, to optimize the extrusion processing and the die design. The results show that the effect of the billet temperature on the product quality is dominate, and its average weight is 0.25. The second important parameter is the ram speed and its average weight is 0.21. The third is the extrusion ratio. Its average weight is 0.18. In addition, it was also found that the effect of the die characteristic parameters on the extrudate is insignificant. Finally, the rationality of the weight of effect was verified through experiments.