The master's thesis investigates the problem connected to the formation of surface cracks after the plastic deformation of aluminum castings, which are cast and annealed in Mariborska Livarna Maribor. The castings in question are flange housings manufactured with high pressure die casting of the alloy AlSi10Mg, the chemical composition of which corresponds to the DIN EN 1706 standard. After die casting, the casts are annealed in order to provide the required strength of the semi-finished products, so that the buyer can properly deform them and thereby insert the rubber component. Throughout the entire production process of making castings in Mariborska Livarna Maribor, the customer's construction requirements are taken into account. However, even though the requirements are fulfilled and quality control, which confirms the suitability of the semi-finished product to the purchaser's required parameter, is carried out during, as well as after the production process, visible cracks still appear on the castings after the deformation.
Thus, the master's thesis analyses samples of castings at all stages of production, and presents an overview of the literature in the field of defects and damages in high pressure die casting, annealing and plastic deformation, in order to determine the type of defects that occur and are responsible for cracks. On the basis of the obtained results, the casting process was optimized by changing the gating system, which led to the improvement of the quality of the castings. We re-analyzed the new castings to check if the experiment was successful and if the initially found defects did not appear anymore or if they appeared on a smaller scale.
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