Zavarivanje trenjem aluminijskih sendvič panela rotirajućim alatom

doctoral thesis

• Title (english): Friction stir welding of aluminium foam sandwich panels
• Author: Matija Bušić
• Mentor: Zoran Kožuh (mentor)
• Mentor: Damjan Klobčar https://orcid.org/0000-0002-6130-0328 (komentor)
• Committee member: Zdravko Schauperl (predsjednik povjerenstva)
• Committee member: Zoran Kožuh (član povjerenstva)
• Committee member: Damjan Klobčar https://orcid.org/0000-0002-6130-0328 (član povjerenstva)
• Committee member: Hrvoje Cajner (član povjerenstva)
• Committee member: Ivan Samardžić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2015-04-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering
• Universal decimal classification (UDC): 621 - Mechanical engineering. Nuclear technology. Machinery ; 669 - Metallurgy

Abstract

U doktorskom radu istraživan je utjecaja brzine zavarivanja, kuta nagiba alata i promjera čela alata na mehanička svojstva i nastanak nepravilnosti u zavarenom spoju pri zavarivanju trenjem aluminijskih sendvič-panela rotirajućim alatom. Obostranim zavarivanjem spajani su aluminijski sendvič-paneli u sučeljenom spoju s umetkom od homogenoga aluminijskoga ekstrudiranoga profila. Aluminijski sendvič-paneli debljine 12 mm kao jezgru imaju aluminijsku pjenu legure AlMg3Si6, a s gornje i donje strane na panelu su limovi aluminijeve legure EN AW-6082-T4 debljine 1 mm. Između panela u sučeljenom spoju postavljen je ekstrudirani profil aluminijeve legure EN AW-6060-T66 širine 3 mm. Pomoću takvoga umetka omogućen je manji pritisak alata na aluminijske sendvič-panele i također dostatan materijal za miješanje koji je nužan u spoju. Iteracijskim pristupom oblikovan je alat za zavarivanje te je ono provedeno alatima s istim oblikom trna, a različitim promjerima čela alata. Sila pritiska alata na materijal FN nije bila regulirani parametar, nego je samo mjerena, kako bi se iz eksperimenta izdvojili zavari dobiveni prekomjernim pritiskom alata. Iz zavarenih spojeva izrađeni su uzorci za statičko vlačno ispitivanje, trotočkasto savojno ispitivanje i analizu nepravilnosti u makrostrukturi. Dobiveni rezultati podvrgnuti su detaljnoj analizi i statističkoj obradbi koja je potvrdila predviđen utjecaj nezavisnih varijabla, te su također izrađeni matematički modeli za predviđanje navedenih mehaničkih svojstava u zavarenim spojevima aluminijskih sendvič-panela.

Abstract (english)

Within the scope of this doctorial thesis influence of welding speed, tool tilt angle and tool shoulder diameter upon the mechanical properties and formation of defects at the friction stir welding of aluminium foam sandwich panels has been investigated. Double side welding was used for producing butt welds of aluminium sandwich panels applying insertion of homogenous aluminium extruded section. Aluminium sandwich panels were 12 mm thick, having the core made of AlMg3Si6 aluminium foam. Both sides of panel were covered with the EN AW-6082-T4 sheeting, 1 mm thick. Between the panels in butt-weld configuration, AW-6060-T66 extruded section 3mm wide was inserted. Such insertion provided lower pressure of the tool upon the aluminium panels, providing also sufficient volume of the material required for the weldment formation.Applying iteration approach, welding tool has been designed and welding has been performed using same form of the probe with different shoulder diameters. Downward force of the tool FN was not a regulated parameter, it was just measured value.Samples for static tensile test, three-point bending test and macrostructural analysis of defects have been cut from the welded joints. Collected results have been thoroughly analyzed and statistically processed. Results confirmed anticipated effects of independent variables. Also, a mathematical model for prediction of analyzed mechanical properties in welded joints of aluminium panels has been established.

• Keywords: zavarivanje trenjem rotirajućim alatom; aluminijski sendvič paneli; brzina zavarivanja; kut nagiba alata; promjer čela alata
• Keywords (english): friction stir welding; aluminium foam sandwich panels; welding speed; tool tilt angle; tool shoulder diameter
• Language: croatian
• URN:NBN: urn:nbn:hr:235:013377
• Study programme: Title: Mechanical Engineering and Naval Architecture; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti (doktor/doktorica znanosti, područje tehničkih znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-04-20 07:47:26