Abstract    In this paper, torsion extrusion (TE) process on 1050 aluminum alloy was investigated by simulation as a severe plastic deformation (SPD) method and the effects of friction coefficient, angular velocity of the rotating die and punch speed on maximum punch force were studied. A finite element (FE) model was developed to simulate the TE process via DEFORM software. The FE results were validated compared with experimental results and then the FE model was used for implementing the set of simulations designed by Taguchi’s L9 orthogonal array. Maximum punch force was determined and put into signal to noise (S/N) ratio and the analysis of variance (ANOVA) techniques to specify the importance and contribution of parameters. The results indicated that the friction coefficient has the most effect on maximum punch force and effects of the angular velocity and punch speed are not sensible. Results analysis represented that maximum punch force enhances by increasing the friction coefficient. Moreover, friction coefficient of 0.18, angular velocity of 0.11 rad/s and punch speed of 0.2 mm/s lead to the minimum punch force.

Keywords    Torsion Extrusion, Maximum Punch Force, Finite Element Simulation, Taguchi Method

چکیده    در این مقاله، فرآیند روزنرانی چرخشی بعنوان یک روش تغییر شکل پلاستیک شدید روی آلیاژ آلومینیوم 1050 با شبیه­سازی بررسی و تاثیر ضریب اصطکاک، سرعت زاویه­ای قالب مدور و سرعت سنبه روی بیشینه نیروی سنبه مطالعه شد. یک مدل اجزای محدود با استفاده از نرم­افزار DEFORM برای شبیه­سازی فرآیند استفاده شد. صحت نتایج شبیه­سازی در مقایسه با نتایج تجربی تایید شد و سپس از مدل اجزای محدود برای اجرای آزمایشات طراحی شده با آرایه متعامد L9 تاگوچی استفاده شد. بیشینه نیروی سنبه استخراج شده و با استفاده از تکنیک­های نسبت سیگنال به نویز و آنالیز واریانس، میزان اهمیت و درصد مشارکت پارامترها مشخص شد. نتایج نشان داد که ضریب اصطکاک بیشترین تاثیر را بر بیشینه نیروی سنبه دارد و تاثیر سرعت زاویه­ای و سرعت سنبه نامحسوس است. با تحلیل نتایج مشخص شد که بیشینه نیروی سنبه با افزایش ضریب اصطکاک افزایش می­یابد. بعلاوه ضریب اصطکاک 18/0، سرعت زاویه­ای 11/0 رادیان بر ثانیه و سرعت سنبه 2/0 میلیمتر بر ثانیه منجر به کمترین میزان نیروی سنبه می­شود.

References    1.      Afrasiab, M., Faraji, G., Tavakkoli, V., Mashhadi, M. and Bushroa, A., "Excellent energy absorption capacity of nanostructured cu–zn thin-walled tube", Materials Science and Engineering: A,  Vol. 599, (2014), 141-144. 2.      Babaei, A., Faraji, G., Mashhadi, M. and Hamdi, M., "Repetitive forging (RF) using inclined punches as a new bulk severe plastic deformation method", Materials Science and Engineering: A,  Vol. 558, (2012), 150-157. 3.      Afrasiab, M., Faraji, G., Tavakkoli, V., Mashhadi, M. and Dehghani, K., "The effects of the multi-pass parallel tubular channel angular pressing on the microstructure and mechanical properties of the cu–zn tubes", Transactions of the Indian Institute of Metals,  Vol. 68, No. 5, (2015), 873-879. 4.      Segal, V.M., Shear-extrusion method. 2006, Google Patents. 5.      Jahedi, M. and Paydar, M.H., "Three-dimensional finite element analysis of torsion extrusion (te) as an spd process", Materials Science and Engineering: A,  Vol. 528, No. 29, (2011), 8742-8749. 6.      Furui, M. and Aida, T., "Development of extrusion-torsion simultaneous processing for grain refinement in magnesium alloys", in IOP Conference Series: Materials Science and Engineering, IOP Publishing. Vol. 63, (2014), 012005. 7.      Mizunuma, S., "Large straining behavior and microstructure refinement of several metals by torsion extrusion process", in Materials Science Forum, Trans Tech Publ. Vol. 503, (2006), 185-192. 8.      Ma, X., Barnett, M. and Kim, Y., "Forward extrusion through steadily rotating conical dies. Part i: Experiments", International Journal of Mechanical Sciences,  Vol. 46, No. 3, (2004), 449-464. 9.      Chino, Y., Sassa, K. and Mabuchi, M., "Enhancement of tensile ductility of magnesium alloy produced by torsion extrusion", Scripta Materialia,  Vol. 59, No. 4, (2008), 399-402. 10.    Khosravifard, A., Jahedi, M. and Yaghtin, A.H., "Three dimensional finite element study on torsion extrusion processing of 1050 aluminum alloy", Transactions of Nonferrous Metals Society of China,  Vol. 22, No. 11, (2012), 2771-2776. 11.    Shamsborhan, M., Moradi, M. and Shokuhfar, A., "Numerical optimization of “planar twist channel angular extrusion” as a novel severe plastic deformation method by doe method",  (2016). 12.    Shamsborhan, M., Shokuhfar, A., Nejadseyfi, O., Kakemam, J. and Moradi, M., "Experimental and numerical comparison of equal channel angular extrusion (ecae) with planar twist channel angular extrusion (ptcae)", Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science,  Vol. 229, No. 16, (2015), 3059-3067. 13.    Okafor, E.C., Ihueze, C.C. and Nwigbo, S., "Optimization of hardness strengths response of plantain fibres reinforced polyester matrix composites (pfrp) applying taguchi robust resign", International Journal of Science & Emerging Technologies,  Vol. 5, No. 1, (2013). 14.    Hashemi, S. and MirzaeiMoghadamb, I., "Influence of nano-silica and polypropylene fibers on bond strength of reinforcement and structural lightweight concrete", Polymer,  Vol. 900, (2014), 6-18mm. 15.    Alimirzaloo, V. and Modanloo, V., "Minimization of the sheet thinning in hydraulic deep drawing process using response surface methodology and finite element method", International Journal of Engineering-Transactions B: Applications,  Vol. 29, No. 2, (2016), 264-271. 16.    Modanloo, V., Hasanzadeh, R. and Esmaili, P., "The study of deep drawing of brass-steel laminated sheet composite using taguchi method", International Journal of Engineering-Transactions A: Basics,  Vol. 29, No. 1, (2016), 103-110. 17.             Modanloo, V., Doniavi, A. and Hasanzadeh, R., "Application of multi criteria decision making methods to select sheet hydroforming process parameters", Decision Science Letters,  Vol. 5, No. 3, (2016), 349-360.