Opredelitev tehologije sistema lokalnega stiskanja za izdelavo tlačnih ulitkov

Gorše, Gregor (author), Mrvar, Primož (mentor)

Tlačno litje je proizvodnji proces, s katerim izdelujemo geometrijsko zahtevne ulitke in je zaradi svojih številnih prednosti široko uporaben v avtomobilski industriji za katero veljajo visoki standardi kakovosti. Namen mojega magistrskega dela je bil izboljšanje končne kakovosti ulitka iz industrijskega projekta, katerega problem je bila krčilna poroznost v nosilnem delu ulitka. V tradicionalno tehnologijo tlačnega litja smo na osnovi temeljitih predhodnih livarskih izračunov in eksperimentalno dobljenih izkušenj aplicirali lokalno stiskanje taline na t. i. kritičnem območju. Preizkuse na tlačnem stroju smo izvedli z desetimi različnimi časi zakasnitve vklopa lokalnega stiskanja od časa, ko je bila livna votlina polna in skupno izdelali 200 različnih vzorcev. V fazi eksperimenta smo uporabili nižji tlak III. livarske faze kot smo ga uporabljali v serijski proizvodnji. Vzorce smo analizirali s štirimi različnimi metodami (RTG, CT analizo, metalografijo in analizo merjenja globine vtiskovanja trna). Poroznosti na opazovanem kritičnem mestu praktično nismo identificirali (majhno smo zaznali smo zaznali le pri času zakasnitve vklopa LS 0,5 s). Ugotovili smo, da so različni časi zakasnitve vklopa LS vplivali na globino vtiskovanja trna, vendar posebnega vpliva na končno kakovost izdelka ni bilo. Tudi nižji uporabljeni tlak III. faze ni poslabšal kakovosti izdelka, smo pa z njim mnogo manj obremenili tlačno orodje in mu tako podaljšali življenjsko dobo. Zastavljeni cilj magistrskega dela je bil dosežen nad pričakovanji in je močno pripomogel k ekonomski učinkovitosti proizvodnega procesa.

• Language: Slovenian
• Keywords: tlačno litje, lokalno stiskanje taline, aluminijeva zlitina, mikrokrčilna poroznost
• Work type: Bachelor thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2017
• PID: 20.500.12556/RUL-95411
• Publication date in RUL: 20.09.2017

GORŠE, Gregor, 2017, Opredelitev tehologije sistema lokalnega stiskanja za izdelavo tlačnih ulitkov [online]. Master’s thesis. [Accessed 20 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=95411

Secondary language

• Language: English
• Title: The definition of squeeze casting technology for production of die castings

Abstract

Die casting is a production process, which enables production of castings with complex geometry and due to many advantages, it is widely used in automobile industry with high quality standards. The aim of my master´s thesis was the improvement of final quality of casting of production project in which we noticed a problem of shrinkage porosity in the main part of casting. We implemented local squeeze casting on a critical area in a traditional die casting technology. The implementation was based on detail numerical calculation of casting process and already existing experiences with die casting. We performed tests on die casting machine with ten different delay times for activation of local squeezing from the time, when the casting cavity was full. In total, we poured 200 samples. During our test we used lower pressure than it is usually used in serial production. The quality of samples was analyzed with four different methods (RTG, CT analysis, metalography and analysies of depths of core squeezing). We didn't found critical shrinkage porosity with none of them. We found out that different delay times influent on the depths of core squeezing, but without any special impact on final quality of casting. The lower pressure, used during the process, didn't influence on the quality of casting, but it less burdened the die casting machine and consequently prolong its shelf life. Our goal was achieved above the expectations and it greatly contributed to the economic efficiency of the production process.

• Keywords: aluminium alloy, die casting, local squeezing, shrinkage porosity