diplomsko delo
Anej Cergol (Author), Maja Vončina (Mentor)

Abstract

Primarnim blokom (ingotom) se v praksi za pretaljevanje v industrijskih pečeh dodaja približno 50 % krožne litine. Pri tlačnem litju krožna litina zajema izmetne ulitke in ulivni sistem, ki je sestavljen iz livnega ostanka (čepa), razdelilnih in dovodnih kanalov ter elementov odzračevalnega sistema (oddušniki). Z dodatkom krožne litine se lahko močno spremenijo oz. poslabšajo mehanske lastnosti končnega izdelka. Z oddušniki, ki so prenasičeni z oksidi, se v končnih izdelkih poveča število vključkov in poroznosti. Čep, ki predstavlja zadnjo talino, ki pride v ulivno napajalni sistem, vsebuje vključke in je prenasičen z železom, ki v mikrostrukturi povzroči tvorjenje faz na osnovi Fe v obliki železovih iglic, ki še dodatno poslabšajo mehanske lastnosti izdelkov. V okviru diplomskega dela smo analizirali vzorce iz zlitine AlSi10Mg(Fe), ki so bili izdelani iz 50 % čiste zlitine (ingota) ter 50 % krožne litine različnega izvora. Na vseh vrstah krožne litine, na bloku pred začetkom taljenja ter na vzorcih po litju smo analizirali kemijsko sestavo. Pretaljene zlitine smo ulili v jekleno kokilo za izdelavo nateznih epruvet. Z nateznim preizkusom ter meritvami trdote po Brinellu smo ugotovili, kako določena vrsta krožne litine vpliva na mehanske lastnosti zlitine AlSi10Mg(Fe). V nadaljevanju smo izdelali obruse za analizo mikrostrukture, pri čemer smo z optičnim mikroskopom analizirali delež in porazdelitev mikrostrukturnih sestavin, ki se tvorijo ob dodatku različne vrste krožne zlitine, ter z elektronskim mikroskopom analizirali faze ter vključke, ki jih z dodatkom različnih vrst krožne litine vnesemo v material.

Keywords

zlitina AlSi10Mg(Fe);krožna litina;mehanske lastnosti;natezni preizkus;mikrostruktura;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL NTF - Faculty of Natural Sciences and Engineering
Publisher: [A. Cergol]
UDC: 669
COBISS: 1732703 Link will open in a new window
Views: 1486
Downloads: 563
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Other data

Secondary language: English
Secondary title: influence of scrap revert type on mechanical properties of AlSi10Mg(Fe) alloy
Secondary abstract: During melting process, 50 % of scrap revert is added to primary aluminium blocks (ingots) in industrial furnaces. At high pressure die-casting, scrap revert contains scrapped products and gating systems, which are containing remains of tablets, channels, overflows and elements of feeding or vacuum system. By adding scrap revert, mechanical properties of final product can be drastically deteriorated. Using elements of feeding systems, which contain oxides, final products are contaminated with inclusions and oxides. Tablet, which represents last melt of gating system, contains inclusions and is saturated with iron, which forms iron rich needles in materials microstructure and additionally deteriorate mechanical properties of final products. Within this diploma work, we analyzed samples made from AlSi10Mg(Fe) alloy containing 50 % of primary alloy ingots and 50 % of different scrap reverts. We analyzed chemical composition on all scrap revert samples, primary alloy ingots before casting and samples after casting. We casted melted samples into steel mould, from which tensile test samples were made. With tensile tests and hardenss measurements according to Brinell, we determined how specific type of scrap revert influences mechanical properties of AlSi10Mg(Fe) alloy. Furthermore, we prepared samples for microstructure analysis, where we analyzed amount and distribution of microstructural constituents which are formed by adding different types of scrap revert. Microstructural analyses were performed using optical microscope and scanning electronic microscope equipped with EDS analysis were we analyzed different phases and inclusions which are entering the melt by adding different types of scrap revert.
Secondary keywords: alloy AlSi10Mg(Fe);scrap revert;mechanical properties;tensile test;microstructure;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Naravoslovnotehniška fak. , Odd. za materiale in metalurgijo
Pages: VI, 35 f.
ID: 10942582