Papers by Keyword: Forging

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Authors: Andreas Krause, Hanns Kache, Georg Ullmann
Abstract: The early detection of defects in forged parts offers economical advantages due to the possibility of sorting them out of the process chain betimes. Hence, no further production costs are occurred by those parts. However, the detection of defects during forging processes is not state of the art. Usually defects of forged parts which are often not obvious and therefore cannot be identified by the press operator are detected by measurements after cooling or later by the customer. In both cases costs occur. Due to the rough conditions in forging shop floors (e. g. high temperatures and forces) the integration of sensors monitoring the forging process is hardly viable. Within the presented research project an in-situ forging process monitoring system is developed which works without sensors in the forging tool and shows results on the process quality directly after forging. A system consisting of two independent concepts (defect-identification and filling-identification) is developed to detect typical forging process failures. On the one hand the defect-identification is able to detect e.g. wrong press energy or insert-position. On the other hand the filling-identification aims to detect, if the cavity is completely filled by the work-piece. Both concepts work in real-time with the help of a computer and a screen visualising the results. One the one hand this paper presents the results of forging trials using the defect-identification and evaluates its capability. On the other hand the concept for the filling identification is presented.
Authors: Tung Sheng Yang, Yuan Chuan Hsu
Abstract: The process of precision gear forging has been developed recently because of its advantages of giving high production rates, improved strength and surface finish. For complete filling up, predicting the power requirement is an important feature of the forging process. To analyze the process of incremental forging of hollow spur gear forms from initially ring-type specimens, a series of simulations using the program DEFORM-3D was carried out. The results of current simulation were compared with the experimental data those obtained by forging of hollow spur gear forms. In addition, the influences of the process parameters such as module, number of teeth, the ratio of the inner radius to the outer radius, friction factor and the height of the billet on the forging force is also examined.
Authors: Yong Ming Guo
Abstract: Point collocation methods have no mesh, no integration. While, the robustness of the point collocation methods is an issue especially when scattered and random points are used. To improve the robustness, some studies suggest that the positivity conditions can be important when using the point collocation methods. For boundary points, however, the positivity conditions cannot be satisfied, so that it is possible to get large numerical errors from the boundary points when using the point collocation methods. The author has proposed a point collocation method with a boundary layer of finite element. In this method, by introducing a boundary layer of finite element in boundary domain of workpiece, unsatisfactory issue of the positivity conditions of boundary points can be avoided, and the complicated boundary conditions can be easily imposed with the boundary layer of finite element. A forging process is analyzed by using the point collocation method with a boundary layer of finite element.
Authors: Daniel Salcedo, C.J. Luis-Pérez, Javier León, Rodrigo Luri, Ignacio Puertas
Abstract: ECAE process is a novel technology which allows us to obtain materials of sub-micrometric and/or nanometric grain size as a result of accumulating very high levels of plastic deformation in the presence of high hydrostatic pressure. This avoids the material being fractured and permits very high values of plastic deformation to be obtained (ε>>1). Therefore, these nanostructured materials can be used as starting materials for other manufacturing processes such as: extrusion, rolling and forging among others; with the advantage of providing nanostructure and hence improving the mechanical properties. In this present study, forging by finite element of materials that have been previously predeformed by ECAE is analysed. MSC.MarcTM software will be employed with the aim of analysing the possibility of manufacturing mechanical components (spur gears) from materials nanostructured by ECAE.
Authors: Hideto Oyama, Soichiro Kojima, Kousuke Ono, Yoshimasa Ito
Authors: Ali Lahouel, Said Boudebane, Alain Iost, Alex Montagne
Abstract: The aim of this research paper is to fabricate a Fe-TiC composite by a novel and simple manufacturing method. The latter is based on two cumulative processes; a conventional sintering (transient liquid phase sintering) and a hot forging with steam hammer respectively. The blinder phase of the studied simples is varied from carbon steel to high alloy steel using alloying additive powders. The obtained outcomes showed that after the sintering process, the relative density of the performed simples is improved from 86% to 95.8% without any densification process. Otherwise, in order to ensure maximum densification and enhance in addition the solubility of the alloying additives the hot forging process is then applied. Indeed, the final obtained composite product is a TiC-strengthened steel with a relative density around 99% (about 6.5 g/cm3 of density) wherein 30% (wt.) of spherical and semi-spherical TiC particles are homogeneously distributed in the metal matrix.
Authors: G. X. Qi, Rui Bin Mei, F Wang, L Bao
Abstract: In order to predict the microstructure evolution and grain size of GH4169 alloy blade in finish forging process and optimize the parameters, a coupled simulation between thermal mechanical and microstructure evolution was realized through embedding the developed user subroutines into the DEFORM-3D software. The temperature, equivalent strain, dynamic recrystallization fraction, average grain size and grain size distribution were predicted and discussed. The experimental results of microstructure under the same forging condition were investigated. The average grain degree in the blade rabbet and body are 8 and 10 respectively. The calculated results of microstructure have a good agreement with the measured value from experimental data and the prediction error of average grain size is less than 6.7%. The developed program is reliable and the accuracy is satisfying. The distribution of grain size along the blade body is decreased from the middle to the leading and back edge. The shape and microstructure after finish forging under the condition of technology parameters meet the user’s requirement. Keywords: Blade, GH4169 alloy, Numerical simulation, Microstructure, Forging
Authors: Chun Ho Liu, A Cheng Wang, Cheng Han Lee, You Min Huang
Abstract: At present, quite a lot of enterprises, small or medium-sized, are engaged in developing the various necessaries of livelihood. And, the forming processes are generally adopted for the methods of parts manufacture. Though various forming technology progress rather well, but the warm working process often cannot obtain fine finished products in the process of manufacturing. The warm working process still needs more adequate techniques. This study is focused on the analyzing of the warm forging-flaring process of brass tube, and the improving of the die design and the working procedures. In this paper, two sets of forging and flaring die are designed for experimental works. The results of simulation are compared with the experiments, the formability of brass tube showed a good agreement. Therefore, we suggest a multi-pass of forging process instead of single-pass process. The stress distributions and loading history in forming processes are also assessed in details. The method used in this study is available in the relative warm forming processes and die design. It is helpful to increase the additional value of products and promote the level of competition in manufacturing industry.
Authors: Soraya Plaza, N. Ortega, Ainhoa Celaya, Jose Antonio Sánchez, Luis Norberto López de Lacalle, Borja Izquierdo
Abstract: The European Higher Education Area has entailed some upheaval since it has involved deep changes in university education. Among the subjects taught in technical education such as Manufacturing Technologies, which involve strong experimental contents, the use of specific tools is helpful for better understanding of such subjects. This article highlights the need for the use of simulation tools in the field of manufacturing processes. The student may achieve optimal understanding and learning from them. They can understand, in a more visual way, complex phenomena that govern different processes and the influence of key variables. Applications related to sheet metal forming, forging and casting processes are presented. The main objective is to enable students to better understand the phenomena that govern the processes of moulding and forming, with the invaluable help of simulation software. The final aim is to ensure that the student reaches an optimum knowledge of moulding and forming processes using simulation software.
Authors: F. Martín, L. Sevilla, A. Camacho, A. Sanz
Abstract: Present work applies the Upper-Bound Theorem (UBT) with Triangular Rigid Blocks (TRB) to metal forming compression processes like plane strain forge, offering an upper limit to required deformation energy. This analytical method, usually used by means of simplified models, is developed here incorporating different effects that impact in evolution of deformation process like shape factor and friction. By means of a new adaptive model, the shape and size of the rigid zones used for the UBT application are optimized according to the ratio of the width and the height of workpiece.
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