• فهرست مقالات Equal channel multi angular pressing

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        1 - Optimal Process Parameters in ECMAP of Al−3% Mg Alloy Strips
        Peyman Mashhadi Keshtiban
        Equal channel angular pressing (ECAP) is one of the most appealing severe plastic deformation (SPD) methods. The proposed equal channel multi angular pressing (ECMAP) process enhances the efficiency of traditional ECAP technique with decreasing the process time. In this چکیده کامل
        Equal channel angular pressing (ECAP) is one of the most appealing severe plastic deformation (SPD) methods. The proposed equal channel multi angular pressing (ECMAP) process enhances the efficiency of traditional ECAP technique with decreasing the process time. In this study, a complete investigation was done by the design of experiment (DOE) by compound Taguchi-Grey technique. FEM was applied by ABAQUS software in order to achieve responses of proposed Taguchi tests. Die geometrical parameters together with an important process parameter were selected as input factors and strain characteristics and also, required process load were selected as responses. The relationships between responses and input factors were obtained by regression analysis. Then, an analysis of variance (ANOVA) was used to determine the influence of each input factor on responses. ANOVA analysis revealed that FC with contribution percentage of 87.21% has the most influential factor on RPL. Furthermore, it was inferred that among input factors, with contribution percentage of 94.57% has the most effect on the PEEQ. Finally, a multi objective optimization study was done by grey relational analysis. It was concluded that among all input factors, die channel angle, friction coefficient (FC), and die corner angle with contribution percentages of 42.30%, 26.08% and 14.84% are the first, second and third most influential factors on objectives, respectively. پرونده مقاله
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        2 - Optimization of ECMAP parameters in production of ultra-fine grained Al1050 strips using Grey relational analysis
        Peyman Keshtiban Mohammad Zadshakouyan Ghader Faraji
        Production of lightweight metals with a higher strength to weight ratio is always the main goal of researchers. In this article, equal channel multi angular pressing (ECMAP) process as one of the most appealing severe plastic deformation (SPD) methods on production of u چکیده کامل
        Production of lightweight metals with a higher strength to weight ratio is always the main goal of researchers. In this article, equal channel multi angular pressing (ECMAP) process as one of the most appealing severe plastic deformation (SPD) methods on production of ultra-fine grained (UFG) materials studied. Two main routes A and C investigated by FEM and compared with each other from different aspects of view. ABAQUS commercial software used to evaluate the maximum strain, maximum required force and strain inhomogeneity index in both routes and obtained results of FEM verified by both theoretical calculations and experimental tests. It is inferred that although equivalent plastic strain (PEEQ) in route A is higher than that in route C, the strain homogeneity as a quality factor for route C is higher. So, route C selected for more investigation and optimization. Grey relational analysis used as the optimization method. Geometrical parameters taken as input variables and both inhomogeneity index and maximum required load taken as objectives. Then, the suggested tests by full factorial method were simulated by FEM. After optimization, it was concluded that the best set up belongs to experiment number 20 which the values of Φ1, ψ1 and ψ2 are 165°, 0° and 15°, respectively. Also, it is inferred that among geometrical parameters, die channel angle (Φ1) is the most effective parameter. پرونده مقاله
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        3 - Modeling and production of high strength Al strips by equal channel multi angular pressing method
        Peyman Keshtiban Mohammad Zadshakouyan Ghader Faraji
        Equal channel multi angular pressing (ECMAP) process is the efficient method to enhance the productivity of ultra-fine grained (UFG) materials, by increasing process continuity and as a result decreasing process required time. Comparing repetitive ECAP method, in the sa چکیده کامل
        Equal channel multi angular pressing (ECMAP) process is the efficient method to enhance the productivity of ultra-fine grained (UFG) materials, by increasing process continuity and as a result decreasing process required time. Comparing repetitive ECAP method, in the same period, the number of passes can be done by ECMAP. In this article, ECMAP of AL strips in two typical annealed and as received conditions studied, and route C was selected as multi pressing route. Values of equivalent plastic strain (PEEQ) and micro-hardness in the cross section of ECMAPed strips obtained both by FE simulations and practical tests, correspondingly. These values also used for obtaining the inhomogeneity of produced ECMAPed strips. Furthermore, mechanical property for both as received and annealed strips before and after pressing, studied experimentally. Also, load-displacement curve during ECMAP process obtained by FEM. For FEM results validation, PEEQ calculated by the analytical method, too. Results show that there is good conformity between FE, analytical and practical results. پرونده مقاله