The bachelor’s thesis was carried out to optimize the elements of the casting-feeding system of grey cast iron heating plate castings with lamellar graphite where shrinkage porosity occurred. The defect was caused by a sub-optimal geometric design of the casting-feeding system and in particular of the gate where the casting metal was last solidified in the casting. First, we measured the casting temperatures in the mold and calculated the heat transfer parameters within the mold. The measurements were used to calculate the heat transfer coefficient in the mold. We also used virtual tools to help us, using ProCast which performs simulations based on the finite element method. To calculate the casting, we needed a 3D virtual CAD model of the mold which we opened into the program. We prepared the appropriate geometry with meshing. We set heat transfers between volumes and defined material properties and boundary conditions. The result of the casting process calculation is a virtual casting flow. Specifically, the flow of liquid metal through the elements of the casting-feeding system and casting cavities, solidification of the metal, and the formation of micro- and macro-shrinkage porosity during solidification.
To avoid shrinkage porosity, we changed the geometry of the gate, which had been hardening before the casting creating visible shrinkage cavities on the casting surface. This was due to the insufficient geometric modulus of the gate. In the first correction, the geometry of the gate was increased to achieve unidirectional solidification. In the second correction, the dimension of the channel was reduced because there were problems with breaking the castings from the casting-feeding system.
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