Vpliv količine krožne litine na kakovost ulitka iz zlitine AlSi9Cu3

Šmalc, Jan (author), Petrič, Mitja (mentor), Vončina, Maja (comentor)

V livarnah in industriji aluminija se sekundarne surovine uporablja za boljši izkoristek in večjo produktivnost procesa. V magistrskem delu smo preučili vpliv deleža krožne litine na kvaliteto AlSi9Cu3 ulitkov. Opazili smo vplive različnih deležev krožne litine na mehanske lastnosti, kot naprimer trdota in natezna trdnost. Sprva smo izvedli enostavno termično analizo (ETA) za pridobitev ohlajevalne krivulje. Ohlajevalni krivulji smo določili karakteristične temperature, ki se pojavljajo med procesom strjevanja zlitine. Za potrditev nastanka faz smo izvedli tudi diferenčno vrstično kalorimetrijo (DSC) in svetlobno (OM) ter elektronsko mikroskopijo (SEM+EDS). Za razumevanje vpliva krožne litine na kakovost ulitka iz zlitine AlSi9Cu3 smo izvedli mikrostrukturno analizo s pomočjo svetlobnega mikroskopa in vrstičnega elektronskega mikroskopa (SEM). Z višanjem deleža krožne litine so se v mikrostrukturi pojavljali različni deleži faz. Poleg tega smo s pomočjo EDS detektorja analizirali vse faze, ki se pojavljajo v mikrostrukturi. V mikrostrukturi se pojavljata dve železovi fazi. Prva je manj škodljiva ?-Al15(Mn,Fe)3Si2, ki se pojavlja v obliki »kitajske pisave« in faza ß-Al5FeSi v igličasti obliki. Delež ?-Al15(Mn,Fe)3Si2 faze pada z večjim deležem krožne litine zaradi nižanja razmerja Mn:Fe. Natezni preizkus je pokazal, da z višanjem deleža krožne litine pada meja tečenja in natezna trdnost, raztezek ob porušitvi pa je nekoliko večji.

• Language: Slovenian
• Keywords: AlSi9Cu3, krožna litina, termična analiza, mikrostruktura, mehanske lastnosti
• Work type: Master's thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2020
• PID: 20.500.12556/RUL-119788
• COBISS.SI-ID: 31264515
• Publication date in RUL: 11.09.2020

ŠMALC, Jan, 2020, Vpliv količine krožne litine na kakovost ulitka iz zlitine AlSi9Cu3 [online]. Master’s thesis. [Accessed 19 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=119788

Secondary language

• Language: English
• Title: Influence of returns and scrap parts on quality of AlSi9Cu3 casting

Abstract

In foundries and aluminium industry, recycle materials are used for higher efficiency and better productivity of process. In this study, the influence of returns and scrap parts on the quality of AlSi9Cu3 castings was examined. The effects of different amounts of returns and scrap parts on the mechanical properties were observed, e.g. hardness and tensile test. First, the cooling curves were recorded by using Thermal Analysis (TA). Later, we analyzed them and determined the characteristic temperatures from the solidification process. To confirm the formation of phases during solidification, Differential Scanning Calorimetry (DSC) analysis was also used. For better understanding of the effects, microstructures were analyzed and observed using Light Optical Microscopy (LOM) and Scanning Electron Microscopy (SEM). By increasing the amount of recycled material, different amounts of phases were formed in the microstructure. In addition, these formed phases were analyzed by using EDS detector. Two iron rich phases occur; less harmful α-Al15(Mn,Fe)3Si2 phase has a »Chinese script« morphology and second β-Al5FeSi phase with needle-like shape. Amount of α-Al15(Mn,Fe)3Si2 phase decreases with addition of return material due to a decrease in the Mn/Fe ratio. The tensile test showed that the yield strength and ultimate tensile strength decreases as the amount of return material increases, elongation is slightly higher. The amount of phases was increased with a higher percentage of return material.

• Keywords: Key words: AlSi9Cu3, return material, thermal analysis, microstructure, mechanical properties