Advanced Materials Research Vols. 472-475

Abstract: Wavelet transform was utilized in vibrant signal processing of air suspension system. A dynamic model of 1/4 engineering vehicle with air suspension system was established. Road surface signal of B grade was input to the dynamic model. Vibrant acceleration curve of under spring mass and dynamic load curve of air suspension was gained. Noise signal of under spring mass acceleration and dynamic load of air suspension system were filtrated by wavelet decomposition. Vibrant acceleration signal of under spring mass and dynamic load signal of air suspension were extracted by wavelet reconstruction. It can provide a theoretical foundation for identifying dynamic load of air suspension system.

Abstract: The finite element simulation of T-tube hydroforming process is conducted with the FEM software Pam-Stamp 2G 2005. The results of numerical simulation and experiment are compared and analyzed. The tube hydroforming simulations under various internal pressures of constant pressure load path are also conducted. The simulation and experimental results of T-tube hydroforming are compared. The results show that the tube wall thickness distribution is more uniform and the hydroforming effect is more ideal in T-tube hydroforming process with constant pressure load path. The constant pressure load path of T-tube hydroforming is relatively easy to implement in the practical production process. Of the four constant pressure load paths of T-tube hydroforming, the simulation result under constant pressure 150MPa is most ideal.

Abstract: As one of the key technologies of industrial equipment for aeronautics and astronautics or others fields, plastic forming technology of precision tube also is the important technologies for some civilian industrial fields. In this article, a few key issues and related researches on plastic forming of high-performance materials precision tube are reviewed.

Abstract: We have take the design of the complex machinery equipment DF900 erecting machine as an example discussed SolidWorks and its module COSMOSWork, COSMOSMotion’s application in bridge erecting machine’s development and design. We established bridge erecting machine’s 3D model, optimized the product’s structure and bridge through-hole speed, provide calculated data for safe and reliable operation of the equipment by finite element calculation. And have provided some certain reference value for use SolidWorks on large, complex mechanical product’s design, research and safety evaluation.

Abstract: the edge crack frequently occurs in hot rolled 5182 alloy. SEM, EDS,etc.are used to analyze the factors leading to the cracks. It is discovered that high sodium content, and coarse intermetallic phase and inclusion are the main reason for these cracks. Meanwhile, some measures are suggested to be taken to avoid this kind cracks: making sure sodium content below 3 ppm; controlling the casting process and chemical composition to avoid coarse intermetallic phase; refining the melting aluminium to eliminate inclusion; setting a suitable scalping depth.

Abstract: In order to improve the work life and reliability of turbodrill diversion liner, the parametric finite element model for turbodrill diversion liner is established by using finite element analysis software, and the result of finite element analysis is shown that the maximum equivalent stress is bigger and the work safety coefficient is low. On the basis of the result of finite element analysis and the characteristics of diversion liner, the improvement scheme is put forward and the finite element analysis is carried out. The analysis result shows that the fillet radius of diversion hole drilling fluid inlet has an importance impact on the maximum equivalent stress. When the fillet radius is 9 millimeter, the maximum equivalent stress is least, the maximum equivalent stress is reduced by 34.82% compared with the original structure, and the safety coefficient reached 1.772, and the results meet the design requirement.

Abstract: By analyzing the characteristics and forming technology of hypoid driving gear, it was suitable for adopting fully enclosed die forging principle to form the gear. Based on different forging methods, three kinds of blank shape and corresponding forming schemes were designed. The three dimensional models of blank and die were created by the UG software. The three forming schemes were simulated by the Deform-3D software. The simulation results of distribution of equivalent stress, distribution of equivalent strain and load-stroke curve were comparatively analyzed. Then the most reasonable scheme was chosen. At last, the rationality of numerical simulation can be further verified by the optimized scheme was proved by experiment.

Abstract: Pre-alloyed Ti6Al4V powder produced by plasma rotating electrode process (PREP) was consolidated by hot isostatic pressing (HIP) under the parameters of 930°C/100MPa/3h. The microstructure is analyzed using scanning electron microscopy (SEM). The tensile property is measured at room temperature, the fracture surface morphology of the tensile specimens was investigated using SEM as well. The results show that the dense body has homogeneous microstructure and fine grain size. The average values of ultimate tensile strength (UTS), yield strength (YS) and elongation (EL) are 1119 MPa, 1043 MPa and 18% respectively. The fracture of specimen presents ductile fracture.

Abstract: For the technology of EBSD, the twinning of metals was described in the form of rotation angle combined with rotation axis, while the twinning of metals was usually described in the form of twinning plane combined with twinning direction. In this report, the corresponding relationship between the two description forms of twinning of face-centered cubic (FCC) metals has been built, based on this relationship, the twinning plane and twinning direction of FCC metals can be determined by EBSD. As the practical application of this relationship above, the twinning variants of two kinds of Ni based superalloys were analyzed.

Abstract: In this paper, the effects of hot extrusion and T5、T6 heat treatment on the microstructures and mechanical properties of ZK60 magnesium alloys are investigated by optical microscope, electronic scanning microscope and mechanical testers. The result shows that both the tensile strength and the elongation of the ZK60 alloy extruded at 380°Care much higher than that of the as-cast alloys, as there are much granular second phases precipitated during the extrusion. The tensile strength of the extruded and T5 treated alloy increases while the elongation decreases faster than that of the extruded alloy. The strengthening effect of the T6 treatment is inferior to that of the T5 treatment. The tensile fracture of the as-cast alloy is brittle fractured while that of the extruded and T5 treated alloy is ductile fractured with lots of deep and even dimples.