Gravity casting in sand molds is one of the oldest casting methods, which is still widely used in industry today. In this process, molten alloy is poured into a sand mould, where the mould cavity is filled by gravity. The quality of the casting is influenced by numerous factors, including the proper design of the gating and feeding system, the casting properties of the melt, the quality of the mould and the solidification conditions. The aim of the diploma thesis was to design the casting technology of gravity sand casting for the production of a fuel injection throttle body housing from aluminium alloy AlSi9Cu3. Numerical simulations of various casting technologies were carried out using the ProCAST software package. Based on the obtained results, moulds were prepared from a sand mixture in the laboratory. Castings were then produced with improved feeding. The porosity of the samples was analysed by computer tomography and the samples were also cross-sectioned for visual inspection of porosity. A comparison of the numerical simulation results and the real samples showed good agreement, which confirmed the reliability of the numerical simulation tool for the design of casting technology. The reference sample, prepared without optimised technology, contained significant porosity, particularly in the bosses of the casting. By adding a chill on the lower part of the casting and an insulated feeder on the upper part, directional solidification was achieved, which significantly reduced the porosity of the final casting. From the obtained results it was determined that porosity was still partially present in the upper half of the final casting, indicating that the feeder was not sufficiently massive to fully feed the entire casting.
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