查看更多>>摘要：A fuel cell will play a part of a module of power generator instead of an internal-combustion engine. It is required to improve the productivity and miniaturizing of the fuel cell. The separator in the fuel cell is an important part. The manufacturing process of carbon/resin separators usually is injection molding or compression forming. On the other hand, the authors have developed die sliding extrusion based on the friction extrusion [1] and side flow extrusion [2]. The die sliding extrusion is a kind of valuable shape extrusion [3,4]. It is applied to manufacturing fuel cell separators which have linear channels on its upper and lower surfaces in the orthogonal direction.
查看更多>>摘要：In the present study, the extrusion process for the AZ31B magnesium alloy was simulated using a DEF0RM-3D software package to establish a database in order to provide input data for artificial neural networks (ANN). The network model was trained by taking extrusion ratio, ram speed, shape complexity and ram displacement as the input variables and the extrusion load and exit temperature as the output parameters. The data from FEM simulations were submitted for ANN as a training file and then ANN built were used to predict the target parameters. The ANN predicted results were found to be in agreement with the FEM simulated and experimental measured ones.
查看更多>>摘要：This paper is focused on determining extrusion process conditions for the first billet and, particularly, on selecting an adequate billet temperature and extrusion speed. It is important to predict these values before adjusting the die to avoid lengthy and unproductive preparation times, and to make die adjustment easier during the tests. With that in mind, this study employs two models to determine the first billet temperature (Tfb) and the extrusion speed (Se) parameters: one that applies regression techniques and another that uses neural networks. The aim of this paper is to present the results obtained by comparing the performance of the two models to determine which one offers the best results. We also analyze whether changing the number of patterns for construction of the models will improve results. The models are based on extrusion process parameters taken from real industry contexts. The results indicate that the variables chosen as predictor variables for the extrusion speed output must be refined.
查看更多>>摘要：In this research, transient finite element simulations of the aluminum extrusion process have been performed in order to study how process parameters influence flow balance and exit temperature. This has been achieved by investigating the influence of billet taper, front billet temperature and ram speed on the run-out velocity and temperature of two separate outlets. Analysis of variance (ANOVA) has been employed to study the effect of each parameter on the velocity and temperature variation of the extruded section. Results show that increasing each of these three parameters results in an undesired increase in exit velocity and temperature. The front billet temperature is found to be the most significant factor affecting the variation. The finite elements software used was Altair HyperXtrude 9.0.
查看更多>>摘要：The influence of the initial temperature and its evolution with large plastic deformation on the formation of the fully coupled chevron shaped cracks in extrusion is numerically investigated. Fully coupled thermo-elasto-viscoplastic constitutive equations accounting for thermal effects, mixed and nonlinear isotropic and kinematic hardening, isotropic ductile damage with micro-cracks closure effects are used. These constitutive equations have been implemented in Abaqus/Explicit code thanks to the user subroutine vumat and used to perform various numerical simulations needed to investigate the problem. It has been shown that the proposed methodology is efficient to predict the chevron shaped cracks in extrusion function of the main process parameters including the temperature effect.
查看更多>>摘要：Integrated automation in a manufacturing plant demands control of manufacturing and material and product flow processes. Efficient data archiving and retrieval, quality control and process automation facilities are essential components which should be deployed to form one coherent system. As managers of extruder plants running look for ways and means for meeting market requirements, the demand for such integrated automation systems is rising.
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