Analiza zaostalih naprezanja u T-spojevima od aluminijskih legura načinjenih AC MIG i DC MIG postupkom

undergraduate thesis

• Title (english): Analysis of residual stresses in aluminium alloy T-joints made by AC MIG and DC MIG process
• Author: Ivan Konjević
• Mentor: Ivica Garašić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2025-02-24, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

Završni rad obrađen je teorijski i eksperimentalno. U teorijskom dijelu naglasak je na zaostalim naprezanjima kao neizbježnoj pojavi koja se pojavljuje u materijalu kao posljedica zavarivanja. Prikazana su svojstva i karakteristike materijala uzoraka u eksperimentalnom dijelu, te su opisani postupci AC i DC MIG zavarivanja. Objašnjeni su razlozi nastanka zaostalih naprezanja nakon zavarivanja kao i svojstva materijala koja utječu na njih. Prikazana je raspodjela zaostalih naprezanja na zavarenim spojevima uz probleme koje uzrokuju te se predstavljene mjere za smanjenje zaostalih naprezanja. Ukratko su opisane najčešće metode mjerenja zaostalih naprezanja, uz naglasak na metodu rendgenske difrakcije.
U eksperimentalnom dijelu provedeno je mjerenje zaostalih naprezanja metodom rendgenske difrakcije na dvama uzorcima zavarenim AC MIG odnosno DC MIG postupkom. Provedena je analiza rezultata te su dobivene distribucije zaostalih naprezanja shodno literaturi. Usporedbom rezultata AC i DC MIG-a mogu se uočiti različiti iznosi i raspodjela zaostalih naprezanja. Provedeno je elektropoliranje uzoraka te analiza dobivenih rezultata.

Abstract (english)

The topic of this final paper was addressed both theoretically and experimentally. The theoretical part focuses on residual stresses as an inevitable phenomenon occurring in materials after welding. Initially, the materials used for the experimental samples are presented, followed by a description of AC and DC MIG welding processes. The reasons for the formation of residual stresses after welding and the material properties that influence them are explained. The distribution of residual stresses is shown, along with the problems they cause, and measures for their mitigation are discussed. The most common methods for measuring residual stresses are briefly described, with an emphasis on the X-ray diffraction method, its working principle, and basic classification, which was utilized in the experimental part of the work.
In the experimental part, residual stress measurements were performed using the X-ray diffraction method on two samples, one welded using the AC MIG process and the other using the DC MIG process. The results were analyzed, and residual stress distributions were obtained according to the literature. By comparing the results of AC and DC MIG, different amounts and distributions of residual stress can be observed. Electropolishing of the samples was performed and the results obtained were analyzed.

• Keywords: zaostala naprezanja; AC MIG zavarivanje; DC MIG zavarivanje; rendgenska difrakcija; elektropoliranje
• Keywords (english): residual stresses; AC MIG welding; DC MIG welding; X-ray diffraction; electropolishing
• Language: croatian
• URN:NBN: urn:nbn:hr:235:367875
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2027-02-20
• Created on: 2025-02-21 11:16:28