Investigation of molten metal flow pattern during the vertical ingate filling in non-pressurized bottom gating system in A356 alloys |
کد مقاله : 2659-IMES-CONGR |
نویسندگان: |
علی خیرابی *1، امیر باغانی2، احمد بهمنی3، پرویز دوامی4، مرتضی تمیزی فر5 1تهران -خیابان حجربن عدی- خیابان 192 غربی - پلاک 91 -واحد 2 غربی 2Razi Metallurgical Research Center, No.8, Fernan St.,Sorkhehesar Road, Km 21 Karadj Makhsous Road, Tehran – IRAN. P.O.Box: 14515-386 3مرکز پژوهش متالورژی رازی 4دانشگاه صنعتی شریف 5associate professor of iran university of science and technology |
چکیده مقاله: |
During the mold filling process, surface turbulence cause the entrainment of oxide films into the bulk liquid which are detrimental to the cast integrity. For avoiding these defects, non-pressurized and bottom-gating systems are strongly recommended for reducing the surface velocity of the liquid metal entering into the mold cavity at the early stages of mold filling. In spite of using mentioned gating system in casting process, exceeding surface velocity from the critical value has been observed at the mold entrance. In this study numerical simulation was used to analyze mold filling and distribution of velocity in different portions of gating system thoroughly, in order to evaluate why surface turbulence was observed even in non-pressurized and bottom-gating systems. It has been concluded that by formation of dead zones and vortex flows in runner's tail, the new entered liquid will push to the ingate and then cavity with a higher velocity. Therefore, it was proved that runner's tail play an important role in making a chaotic regime and unexpected flow pattern in the ingate. This means that, design based on conventional gating system ratio is not valid enough to avoid surface turbulence. |
کلیدواژه ها: |
gravity casting, surface turbulence, gating system, numerical simulation, velocity distribution, vortex flow |
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