Advanced Materials Research Vols. 399-401

Abstract: Apply the function of FBM Mill and FBM Drill built in MasterCam to achieve the automatic NC programming and machining of solid parts.The feature modeling of parts is produced in Solidworks, and then converted to MasterCam. After the stock size of parts and FBM parameters are set, the features of parts are recognized automatically; and all of the 2D toolpaths of parts are automatically generated in a specified machine. Finally, the automatically generated NC toolpaths based on features are verified by simulating. FBM technology is adopted to eliminate the manual processes involved in identifying features for programming milling and drilling operations on solid parts, thus greatly increasing the efficiency and flexibility of programming, which is an effective method of achieving automatic NC programming.

Abstract: Engineering in general is a process-intensive domain. Processes and process models underpin the activities of every Engineering discipline, ensuring consistent outputs by sequencing the right activities in the correct order. Acknowledging the importance of process models, there is a clear need for effective methods for verifying such models to ensure efficiency and correctness. This paper introduces a new formal methodology for the analysis and verification of processes, Behavior Engineering (BE) [1]. BE has proven very effective when applied to the development of process models. In this example, the discipline is Software Engineering, yet it is argued that the approach can be applied to any process or set of processes from Chemical, Materials and Metallurgical Engineering.

Abstract: Multi-track laser cladding is necessary in the forming of parts. The overlap between neighbor tracks plays an important role, which determines the quality and surface smoothness of the clad layer. In this paper, numerical simulation of the multi-track laser cladding process is studied. The heat source of laser spot is applied by updating the profile of clad region and the location of the moving laser spot. The clad profile of overlapped track was obtained, from which the surface roughness was analyzed by the variation of overlap ratio. Meanwhile, experiments were carried out to evaluate the effect of overlap ratio. The simulated and the experimental results are in good agreement; both show that there is an optimal overlap ratio to achieve best surface roughness.

Abstract: The finite element model of the roof of aluminum high-speed train was established, double ellipsoid heat source was employed, and heat elastic-plastic theory was used to simulate welding residual stress of the component under different welding sequence based on the finite element analysis software SYSWELD. The distribution law of welding residual stress was obtained. And the effects of the welding sequence on the value and distribution of residual stress was analyzed. The numerical results showed that the simulation data agree well with experimental test data. The maximum residual stress appears in the weld seam and nearby. The residual stress value decreases far away from the welding center. Welding sequence has a significant impact on the final welding residual stress when welding the roof of aluminum body. The side whose residual stress needs to be controlled should be welded first.

Abstract: A three-dimensional mathematical model has been established to research the relation between the plasma reflection and status of keyhole during the keyhole PAW processing. It has been found that the strength of the plasma reflection is related to the keyhole dimension. Another condition to make the plasma refection appearance is that the keyhole or concave in the pool must be unsymmetrical about the axis of the plasma arc. The mechanism of detecting circuit designed based on the fact that the plasma refection is able to indicate the status of keyhole is mathematically studied. The result shows that the voltage signal in the detecting circuit can be used to indicate the status of keyhole.

Abstract: In this paper a typical box beam structure on certain high speed power car was taken as study object, Based on the finite element analysis software SYSWELD, established the material parameters database for SMA490BW weathering steel, and performed the numerical simulation for the welding of typical box beam structure of side beam of high speed bogie, comparison between the simulation results and that of experiment test verified the existing welding procedures. For the purpose of studying the influence of welding sequence on the residual stress and providing theoretical support for actual production, the residual stress under different welding sequences was investigated then.

Abstract: A commercial software, MAGMASOFT, was used to simulate the ZM5 shell with different materials of chills. The calculated results of solidification are obtained. Shrinkage porosity is predicted by means of a built-in porosity criterion. It shows that using the different materials of chills, such as copper, gray iron and steel, a large amount of shrinkage porosity defects are formed in ZM5 shell. However, with graphite as the material of chills, shrinkage porosity defects of ZM5 shell can be effectively reduced.

Abstract: The reasonable blank shape is very important for drawing forming quality of sheet. In this paper, the blank shape is obtained by inverse calculation based on final drawing workpiece, with finite element software. The optimal blank contour is determined by modifying the 3D models of final drawing workpiece and comparing with forming quality of the different inverse calculated blank shapes, according to the stress and the material flow law in drawing process. The results show that, in the case of the given shapes of workpiece, the blank shapes with high precision can be obtained, the formability becomes better, and the number of drawing forming can be reduced by using the method. The method may also contribute to the drawing of large and medium-sized panels, rectangular boxes and special-shaped parts.

Abstract: A simplified method called “Pseudo Inverse Approach” (PIA) has been developed for the axi-symmetrical cold forging modeling in this paper. The traditional “Inverse Approach” (IA) based on the assumptions of the proportional loading and simplified tool actions may quickly give a fairly good strain distribution, but poor stress estimation. Meanwhile the PIA proposed in this paper not only keeps the advantages of the Inverse Approach but also gives good stress estimation by taking into account the loading history. To fulfill this aim, some kinematically admissible intermediate configurations represented by the free surface are used to consider the deformation paths without classical contact treatment. A new direct algorithm of plasticity integration has been used by using the notion of equivalent stress and the tensile curve, leading to a very fast and robust plastic integration procedure. An axi-symmetrical forging has been taken as an example to validate the PIA.

Abstract: The effects of Mn addition on the microstructure and hardness of 6061 aluminum alloy were studied by means of scanning electron microscope (SEM) , energy dispersive X-Ray Analysis (EDX), X-ray diffraction (XRD) and hardness tester in this work. The results shows that rod and fishbone AlSiFeMn phase will be formed in the alloy with Mn addition in 6061 aluminium alloy, and the AlSiFeMn phase increases with the increasing of Mn content . By the mean of XRD, the Al4.07 Mn Si0.74 phase is found in the 6061 aluminium alloy from 0.7% to 1.5% Mn. The hardness increases with the increasing of Mn contents both for as-cast and for T6 heat treatment. However, the hardness growth rate for as-cast is much more than that for T6 heat treatment at the same Mn addition in the 6061 alloy. Mn has a little effect on the hardness for T6 heat treatment in 6061 alloy.