| Bimetal composite materials gain much attention because they have more advantages than single metal. In this research,4045/3003 composite ingot has been manufactured by direct cooling continuous casting. The problem of interfacial bonding strength can be solved by this method, and metallurgical bonding can be obtained.In this paper, the Fluent simulation software contained in the commercial finite element software ANSYS is used to establish a mathematical model to describe the process of coated casting of composite ingot. The mathematical model can accurately describe the temperature field and the flow filed of the process of the coated casting of the composite ingot and the process of solidification of the composite ingot In the paper, the numerical simulation is used to study the temperature field and the flow filed of the process of solidification during the process of coated casting of the ?140mm/?110mm aluminum alloy composite ingot. The influence of divided flow method, casting speed, casting temperature, liquid height of skin-material and cooling intensity of core-material on the temperature field, flow field and composite interface during the process of composite casting has been studied in detail.The conclusions obtained from the simulation are as follows:(1) when the skin-material are divided densely and unevenly, the melt flows gently and the temperature distributes evenly.(2) with the increasing of the casting speed, the depth of the liquid cave of the core-material increases, and temperature of the supporting outer surface decreases and its thickness decreases; an excessive casting speed makes the skin-material gain back too much heat after contacting the supporting layer, and the core-material remelts, which results in the destruction of the composite interface; when the casting speed is too low, the metallurgical bonding can't be obtained because of the too long cooling time which makes the temperature of outer supporting layer of core-material too low, when other conditions keep unchanged and the casting speed is 100mm/min, the best compound effect can be obtained.(3) increasing the temperature of skin-material has little influence on the process of solidification, but an appropriate increase can increase the smoothness of the outer surface of the supporting layer and be conducive to the composite of the alloys.(4) increasing of the cooling intensity of the mould in the core-material, decreasing of the depth of liquid cave and increasing of the thickness of supporting layer, the temperature of the outer surface of the supporting decreases. The best effect can be obtained when the cooling intensity of the mould is 3000 Wm-2K-1,(5) the liquid level of the skin-material should be a higher value, which is close to the liquid level of the core-material, in order to decrease the difference in pressure between the inner and the outer of the supporting layer.(6) when the secondary cooling water is too low, remelting may occur around the composite surface because of the small thickness of the core-material's supporting layer and the lower temperature of its outer; an excessive secondary cooling water, which make the thickness of the supporting layer bigger and the temperature of its outer higher, would easily lead to a lower interfacial bonding strength, even lead to the experiment failure.(7) the best technological parameters have been obtained with which the production of bimetal coated ingot with high interfacial bonding strength can be guided:(1) the skin-material should be divided densely and unevenly; (2) the cooling speed is around lOOmm/min; (3) the casting temperatures of the two alloy are 1000K, and the temperature can be increasing accordingly; (4) the liquid level of the two alloys should keep the same; (5) the cooling intensity of the core-material is around 3000 Wm-2K-1. |
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