20.500.12556/RUL-149678 Karakterizacija nekovinskih vključkov v zlitinah Pb-Ca-Sn magistrsko delo Characterization of non-metallic inclusions in Pb-Ca-Sn alloys master's thesis V magistrski nalogi so bili raziskovani in kategorizirani nekovinski vključki v dveh svinčevih zlitinah Pb-Ca-Sn, ki se uporabljajo za izdelavo kislinskih vžignih akumulatorjev. Odlikuje jih dolga življenjska doba, nizka potreba po vzdrževanju in ter ohranjanje moči v stanju pripravljenosti. Nekovinski vključki, ki se pojavljajo v svinčevih zlitinah so nezaželeni in negativno vplivajo na potek litja ter mehanske in elektrokemijske lastnosti zlitin. Nekovinski vključki večinoma nastanejo zaradi stika taline z atmosfero. Kemijska analiza zlitin je bila opravljena z optičnim emisijskim spektrometrom na vzbujanje z iskro. Vzorci so bili pregledani s svetlobnim in elektronskim mikroskopom, ki omogoča analizo kemijske sestave. Potek strjevanja in taljenja dveh zlitin je bil opredeljen z diferenčno vrstično kalorimetrijo. Na podlagi kemijske sestave zlitin so bili opravljeni termodinamični izračuni ravnotežnega in neravnotežnega strjevanja, ki pomagajo pojasniti tvorbo vključkov. Rezultati kažejo, da se v zlitinah Pb-Ca-Sn nahajajo večinoma oksidni vključki. Identificirali smo nekovinske vključke s kemijsko sestavo, ki opredeljuje stehiometrijo oksidov PbO2, Pb2O3, Al2O3 in CaO. Največ vključkov se nahaja blizu površine vzorca, ki je imela največ stika z atmosfero. Delež nekovinskih vključkov je mogoče znižati z uporabo zaščitne atmosfere med taljenjem. The master's thesis analysed and categorized non-metallic inclusions in two lead alloys Pb-Ca-Sn, which are used for production of lead-acid starter batteries. These batteries are characterized by long lifespan, low maintenance requirements, and the ability to maintain power in a ready to use state. Non-metallic inclusions that occur in lead alloys are undesirable and have a negative impact on the casting process, as well as on mechanical and electrochemical properties of the alloys. Non-metallic inclusions mostly occur due to contact between the melt and the atmosphere. Chemical analysis of the alloys was performed using spark-induced optical emission spectrometry. Samples were examined using light and electron microscopy, which allows analysis of chemical composition. The solidification and melting processes of the two alloys were studied using differential scanning calorimetry. Thermodynamic calculations of equilibrium and non-equilibrium solidification were defined based on the chemical composition of the alloys, which help explain the formation of inclusions. The results show that Pb-Ca-Sn alloys mostly contain oxide inclusions. Non-metallic inclusions with the chemical composition of PbO2, Pb2O3, Al2O3, and CaO were identified. Most inclusions are located near the surface of the sample, which had the most contact with the atmosphere. The proportion of non-metallic inclusions can be reduced by using a protective atmosphere during melting. Kontinuirno litje nekovinski vključki rafinacija svinec svinčene zlitine. Continuous casting lead lead alloys non-metallic inclusions refining. true false false G. Šegel Slovenski jezik Angleški jezik Magistrsko delo/naloga 2023-09-08 09:01:11 2023-09-08 09:01:12 2023-10-05 11:25:52 0000-00-00 00:00:00 2023 0 Ljubljana 0 Ljubljana XVII, 57 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 2026-09-26 669 95420 167128579 17984.pdf 17984.pdf 1 39296F5285350D93698B80222D6C6C9F a4632d8043aefc4531bb6b5d461da9e4975dfbafee6f37a9c4ddd5ddee5325f1 7e72ce82-4e15-11ee-9323-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=174167 Naravoslovnotehniška fakulteta 0 0 0