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Improving the quality of automobile wheel discs cast by the low-pressure casting method
Bělota, Martin ; Krutiš, Vladimír (referee) ; Kaňa, Václav (advisor)
The thesis deals with the identification of defects occurring in cast automotive wheels. The thesis also includes the design and experimental verification of measures that lead to an increase in the quality of production. The first chapter of the theoretical part deals with the occurrence of gases in aluminium alloys, especially hydrogen, its sources, solubility in aluminium alloys and the formation of gas cavities in castings. The second chapter describes ways of degassing the melt by vacuuming and bubbling with inert and active gases. The third chapter deals with controlled melt gasification, the purpose of melt gassing and methods of controlled gassing. The fourth chapter is devoted to the defects that occur in automotive wheels produced by lowpressure die casting technology. The fifth chapter describes the aluminum alloy AlSi7Mg0.3, which is used for the manufacture of cast wheels. It also describes the heat treatment of cast wheels. The sixth chapter deals with the practical part of the thesis, which includes the identification of defects using microscopic and radiographic methods. The next part describes the design and execution of an experiment in which Probat-Fluss MIKRO 100 was selected to improve the quality of production based on the results of defect identification. At the end of the practical part, the conducted experiment is evaluated, which also served to verify the effectiveness of Probat-Fluss MIKRO 100.
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