Experimental Study and FEM Simulation of the Effect of Significant Parameters in the Thixoforging of the Gearbox Cap
الموضوعات : فصلنامه شبیه سازی و تحلیل تکنولوژی های نوین در مهندسی مکانیک
امین کلاه دوز
1
(دانشجوی دکتری، دانشکده مکانیک، دانشگاه صنعتی نوشیروانی بابل)
سلمان نوروزی
2
(دانشیار، دانشکده مکانیک، دانشگاه صنعتی نوشیروانی بابل)
محمد بخشی جویباری
3
(استاد، دانشکده مکانیک، دانشگاه صنعتی نوشیروانی بابل)
سید جمال حسینی پور
4
(دانشیار، دانشکده مکانیک، دانشگاه صنعتی نوشیروانی بابل)
الکلمات المفتاحية: Semi-solid Forming, Thixoforging, Isothermal Forging, Al-A356,
ملخص المقالة :
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
[1] Chou H.N., Govender G., Ivanchev L., Opportunities and challenges for use of SSM forming in the aerospace industry, TTP, solid state phenomena, vol. 116-117, 2006, pp. 92-95.
[2] Jaffari M.R., Zebarjad S.M., Kolahan F., Simulation of A356 Aluminium Alloy Using finite element method, Matertials science engineering A, vol. 2007, 454-455.
[3] Motegi T., Tanabe F., sugiura E., Continuous casting of semisolid aluminium alloys, Material Science Forum, vol.1, 2002, pp. 203–208.
[4] Shiomi M., Takano D., Osakada K., Otsu M., Forming of aluminum alloy at temperatures just below melting point, Internatinal Journal Machine Tool Manufacture, 2003, pp. 229–235.
[5] Giordano P., Chiarmetta G., Thixo and rheo casting: comparison on a high production volume component, Proceedings of the 7th international conference on semisolid processing of alloys and composites, Japan, vol. 2002, pp. 665–670.
[6] S.M. Ghavamodini, S. Nourouzi, H. Baseri , A. Kolahdooz, S. Kaboli, M. Botkan, A Study of the Effects of Semi-solid Casting Parameters on the Microstructure and Hardness of Al-A356 Alloy, Advances in Materials and Processing Technologies, Istanbul, Turkey , July 2011.
[7] Nourouzi S. Ghavamodini S.M. Baseri H. Kolahdooz A., Botkan M., Microstructure evolution of A356 aluminum alloy produced by cooling slope method, Advanced Material Research vol. 402, 2012, pp.272-276.
[8] Tzimas E., Zavaliangos A., Evolution of near-equiaxed microstructure in the semisolid state, Material Science Engineering A, vol. 289, 2000, pp. 228–240.
[9] Nourouzi S., Bakhshi M., Kolahdooz A., Hosseinipour S.J., Effect of temperature on the Microstructure of semi-solid casting in cooling slope method, Aerospace Mechanics Journal, under Published, vol. 19(3), 2012, pp. 55-65, Persian Language.
[10] Bames H.A., Thixotropy—a review, Journal of Non-Newtonian Fluid Mechanic, Vol. 70, 1997, pp. 1-3.
[11] Nourouzi S., Kolahdooz A., Botkan M., Behaviour of A 356 alloy in semi-solid state produced by mechanical stirring, Advanced Material Research, vol. 402, 2012, pp.331-336.
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.
[12] Kang C.G., Cho J.S., Kim K.H., The effect of strain rate on macroscopic behavior in the compression forming of semi-solid aluminumalloy, Journal of material Process Technology, 88, 1999, pp. 159–168.
[13] Kang C.G., Kim H.H., Cho S.H., Evaluation of microstructure and mechanical properties by using nano/micro-indentation and nanoscratch during aging treatment of rheo-forged Al 6061 alloy, Material Science and Engineering A, vol. 485, 2008, pp. 272–281.
[14] Kang C.G., Bae J.W., Seol D.Y., Lee S.M., Die life prediction considering thermal fluid flow and solidification phenomenon in rheology process, Journal of material Process Technology, vol. 201, 2008, pp. 336–341.
[15] Pouyafar V., Sadough S.A., Hosseini F., Rahmani M.R., Design of experiments for determination of influence of different parameters on mechanical properties of semi-solid extruded parts, Transaction of Nonferrous Metal Society of China, vol. 20, 2010, PP.794-797.
[16] Fadavi Boostani A., Tahamtan S., Microstructure and mechanical properties of A356 thixoformed alloys in comparison with gravity cast ones using new criterion, Transaction of Nonferrous Metal Society of China, vol. 20, 2010, pp. 1608-1614.
[17] Fadavi Boostani A., Tahamtan S., Effect of a novel thixoforming process on the microstructure and fracture behavior of A356 aluminum alloy, Materials and Design, vol. 31, 2010, pp. 3769–3776.
[18] Fadavi Boostani A., Tahamtan S., Microstructural characteristics of thixoforged A356 alloy in mushy state, Transaction of Nonferrous Metal Society of China, vol. 20, 2010, pp. 781-787.
[19] Martin C., Kumar P., Brown S.B., Shear rate thickening flow behavior of semi-solid slurries, Matallurgical Transaction A, vol. 4, 1993, pp. 1107-1116.
[20] llegbusi O.J., Brown S., Mold filling of semisolid metal slurries, Journal of Material Engineering Perform, vol. 4, 1995, pp. 486-493.
[21] Zavaliangos A., Lawley A., Numerical-simulation of Thixoforming, Journal of Material Engineering Perform, Vol. 4, 1995, pp. 40-47.
[22] حجتی م.ح.، بخشی م.، حسینی پور س.ج.، مبانی و کاربرد آهنگری سرد و گرم، چاپ اول، انتشارات مازندران، بابلسر، 1385.
[23] Hasford W.F. Caddell R.M., Metal forming (mechanics and metallurgy), second edition, prentice hall, 1993.
