Experimental Study and FEM Simulation of the Effect of Significant Parameters in the Thixoforging of the Gearbox Cap

Document Type : Persian


1 PhD Student, Department of Mechanical Engineering, Babol University of Technology, Mazandaran, Iran

2 Associate Professor, Department of Mechanical Engineering, Babol University of Technology, Mazandaran, Iran

3 Professor, Department of Mechanical Engineering, Babol University of Technology, Mazandaran, Iran


Semi-solid forming processes are now used for producing near net shape parts especially in the automotive and aircraft industries. Non Newtonian rheology of semisolid alloys and its dependence on the various parameters such as reheating cycle, method used to produce non-dendritic structure, thermo-shear history etc. have made the simulation of the flow behavior of semisolid material a difficult mater in engineering. One of the semi-solid forming processes is thixoforging process. Thixoforming takes place between liquidous and solidous temperature and liquid phase and solid one that exists at the same time. The significant parameters in this method can be strain rate, friction and temperature terms. In this research, the simulation of thixoforging process is done using Deform-3D software and parameters such as friction factor, process temperature and rams speeds are studied. In order to verify the model, thixoforging tests were conducted with various parameters and under isothermal conditions on the A356 Alloy. The comparison of numerical results at different solid fractions with experimental data is shown. These simulations can provide an accurate model of the process. Also the simulation results had shown the effects of various parameters. Results showed that increasing the mould temperature, causes more inhomogeneous microstructure and therefore the hardness and forming force decreased %12.5 and %20.6 respectively


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4- نتیجه گیری
نتایج شبیه­سازی فرآیند تیگزوفورجینگ آلومینیم A356 برای تولید قطعه درپوش گیربکس به صورت زیر قابل ارائه می­باشد.
شبیه سازی انجام گرفته و ارائه پارامترهای وابسته به نرم افزار مربوطه به خوبی سیلان آلیاژ را در حالت نیمه جامد تقریب زده است. نتایج نشان داده که هنگامی که ماده در حالت خمیری شکل باشد، نیروهای شکل­دهی کاهش یافته که در این صورت هزینه تولیدی برای قطعه نیز کاهش خواهد یافت. کاهش اصطکاک تا لحظه 35% تغییر در دمای قطعه اتفاق نمی­افتد اما پس از آن تغییری در حدود 2% را بوجود می­آید. همچنین با کاهش اصطکاک بدلیل کاهش نیروهای وارد بر قطعه، جریان یافتن ماده به صورت آرام می­گردد که این امر باعث کاهش عیوبی از قبیل رویهم افتادگی لبه­ها می­گردد. با افزایش نرخ کرنش در ابتدا نیروهای لازم برای شکل­دهی کاهش می­یابد و سپس بدلیل پدیده کار سختی، نیرو افزایش می­یابد.
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