20.500.12556/DKUM-92415 Vakuumsko litje stelitne zlitine magistrsko delo Vacuum casting of stellite alloy Magistrsko delo obravnava razvoj postopka izdelave stelitne zlitine v laboratorijskem okolju, ki se uporablja v zobni protetiki za kovinska ogrodja zobnih protez. Predstavljeni so postopki vakuumskega indukcijskega litja in termo-mehanske obdelave (visokotemperaturno homogenizacijsko žarjenje, mehko žarjenje in kovanje). Obrazložene so mehanske in fizikalne lastnosti ter mikrostruktura stelitnih zlitin v odvisnosti od pogojev, načina litja in termo-mehanske obdelave. Pojasnjena je prednost vakuumskega indukcijskega litja v kovinske kokile v primerjavi z litjem v enkratne peščene forme. Magistersko delo obravnava tudi okoljski vidik vakuumskega indukcijskega taljenja in ulivanje stelitnih zlitin v forme. S svetlobnim in vrstičnim elektronskim mikroskopom je bila v okviru raziskav opravljenih v tem magistrskem delu okarkterizirana mikrostruktura sletitne zlitine. Določene so bile tudi fizikalne in mehanske lastnosti te stelitne zlitine. V sklepnem delu smo dokazali, da je lahko z uporabo vakuumskega indukcijskega litja in naknadne termo-mehanske obdelave zmanjšana prisotnost livarskih napak. To so lunkerji, kristalne in blokovne izceje, razpoke, vključki, plinska in krčilna poroznost. Tako izdelamo stelitno zlitino, ki ustreza lastnostim, ki so za ta tip zlitin podane v standardu ASTM F75 The master's thesis examines the laboratory process of manufacturing a stellite alloy used in dental prosthetics for the metal frameworks of dental prostheses. The thesis presents vacuum induction casting and thermo-mechanical processing techniques, including high-temperature homogenisation annealing, soft annealing, and forging. It analyses the mechanical and physical properties, as well as the microstructure of stellite alloys, depending on the casting conditions and thermo-mechanical treatments. The thesis also explains the advantages of vacuum induction casting into metal moulds, compared to casting in single-use sand moulds. Additionally, the thesis considers the environmental aspects of vacuum induction melting and casting of stellite alloys. As part of the research conducted in this master's thesis, the microstructure of the stellite alloy was analysed using optical and line-scanned electron microscopy, and its physical and mechanical properties were determined. The conclusion demonstrates that the use of vacuum induction casting combined with subsequent thermo-mechanical processing can reduce the presence of casting defects, such as shrinkage cavities, dendritic and blocky segregations, cracks, inclusions, and gas or shrinkage porosity. This enables the production of a stellite alloy that meets the properties specified in the ASTM F75 standard. Stelitne zlitine vakuumsko indukcijsko litje kovinska kokila poroznost karbidi mikrostruktura Stellite alloy vacuum induction casting metal moulds porosity carbides microstructure true true false [K. Križovnik] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2025-04-07 12:11:59 2025-05-05 13:56:56 2025-05-08 03:20:48 0000-00-00 00:00:00 2025 0 Maribor 0 Maribor 1 spletni vir (1 datoteka PDF (XI, 70 f.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 621.74,04:669.255(043.2) 234996995 MAG_Krizovnik_Katja_2025.pdf MAG_Krizovnik_Katja_2025.pdf 1 8CC2EA635A56E47DCEBC8DA2BB400745 b1dac09d279dc2574009e4f69367e650228a542d5a44586008e8ef7dc8484de9 4b6aab36-2797-11f0-a86b-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=190602 Fakulteta za strojništvo 0 0 0