diplomsko delo
Mitja Rupnik (Author), Maja Vončina (Mentor)

Abstract

Aluminij je med kovinami eden izmed najpomembnejših materialov, ki se ga uporablja v najrazličnejših aplikacijah. Da aluminiju izboljšamo lastnosti mu dodajamo legirne elemente kot so: baker, mangan, magnezij, silicij, cirkonij, železo, itd. Vsak legirni element se dodaja s točno določenim namenom. Najpogostejše aluminijeve zlitine so iz sistemov Al-Cu, Al-Mg in Al-Si, med katere spada tudi naša preiskovana zlitina Silafont-36 (AlSi10MnMg). Silicij je eden izmed najbolj pogosto dodanih legirnih elementov, saj izboljša livnost in poveča obrabno obstojnost orodja. Mangan v zlitini preprečuje lepljenje ulitka na orodje in preprečuje tvorjenje škodljive faze ?-Al5FeSi, ki zaradi igličaste oblike povzroča zarezni učinek in poslabšuje mehanske lastnosti. Magnezij tvori intermetalne faze in izločke, ki zlitino še dodatno utrjujejo. Za izboljšanje duktilnosti se dodaja stroncij, ki povzroči spremembo morfologije evtektskega ?-Si in posledično dobimo boljše obdelovalne lastnosti. V okviru diplomske naloge smo raziskovali, kakšen vpliv ima vanadij na zlitino Silafont-36. Izdelali smo štiri vzorce z različnimi koncentracijami vanadija v zlitini. S pomočjo ohlajevalne krivulje smo analizirali, kako vanadij vpliva na potek strjevanja. Opravili smo še diferenčno vrstično kalorimetrijo (DSC analizo) s katero smo dobljene rezultate preverili in potrdili. S pomočjo programa Thermo-Calc smo izračunali potek ravnotežnega in neravnotežnega strjevanja glede na koncentracije elementov v eksperimentalnih zlitinah. Kot zadnje smo pripravili še vzorce za analizo mikrostrukture. Zanimalo nas je katere so novo nastale faze v zlitini z vanadijem in njegov vpliv na izoblikovanje mikrostrukture. Vse dobljene rezultate smo okarakterizirali in podali celoten vpliv vanadija na strjevanje in izoblikovanje mikrostrukture zlitine Silafont-36. Ugotovili smo, da vanadij zviša likvidus temperaturo in razširi območje strjevanja, v mikrostrukturi pa dobimo novonastalo fazo Si2V.

Keywords

zlitina Silafont-36;dodatek vanadija;strjevanje;termodinamični izračun;termična analiza;mikrostruktura;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL NTF - Faculty of Natural Sciences and Engineering
Publisher: [M. Rupnik]
UDC: 669
COBISS: 1841759 Link will open in a new window
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Other data

Secondary language: English
Secondary title: characterization of AlSi10MnMg alloy with vanadium addition
Secondary abstract: Aluminium is one of the most important materials among metals, which is used in a wide range of applications. To improve the properties of aluminium, alloying elements such as: Copper, Manganese, Magnesium, Silicon, Zirconium, Iron, … are added. Each alloying elements is added for a specific purpose. The most common aluminium alloys are from the Al-Cu, Al-Mg and Al-Si systems, which include our investigated alloy Silafont-36 (AlSi10MnMg). Silicon is one of the most commonly added alloying elements, because it improves castability and increases wearability of the tool. Manganese in the alloy ensures that the alloy casting does not stick to the die and prevents the formation of the harmful phase ?-Al5FeSi, which, due to needle shapes, produces a notch effect and aggravates mechanical properties. Magnesium forms intermetallic phases and precipitates, which further strengthen the alloy. In order to improve ductility, strontium is added, which causes a charge in morphology of eutectic ?-Si, and consequently, better treatment properties are achieved. Within the diploma thesis, we investigated the influence of vanadium on the alloy Silafont-36. We made four samples with different concentrations of vanadium in the alloy. Using the cooling curve, we analysed effects of vanadium on the solidification process. We also performed the differential scanning calorimetry (DSC analysis) in order to verify and confirm gained results. Using the Thermo-Calc program we calculated the course of equilibrium and non-equilibrium solidification with respect to the concentrations of the elements in the experimental alloys. Finally, we also prepared samples for analysing of the microstructure. We were interested in what are the newly formed phases in alloys with vanadium and its influence on the formation of the microstructure. All obtained result were characterized and the total influence of vanadium on the solidification and microstructure formation in the alloy Silafont-36 was reported. We have found that vanadium raises the liquidus temperature and broadens the solidification region, in the microstructure, and the newly formed Si2V phase is obtained.
Secondary keywords: alloy Silafont-36;the addition of vanadium;solidification;thermodynamic calculation;thermal analysis;microstructure;
Type (COBISS): High school thesis
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Naravoslovnotehniška fak., Odd. za materiale in metalurgijo
Pages: XI, 36 f.
ID: 11223566