Mikrotrdota v zvarnih spojih raznorodnih visokotrdnostnih aluminijevih zlitin

Margon, Uroš (author), Trdan, Uroš (mentor), Klobčar, Damjan (comentor)

V zaključni nalogi smo obravnavali mehanske lastnosti aluminijevih zlitin za gnetenje za uporabo v transportni industriji. Osredotočili smo se na trdnostne lastnosti, pridobljene po postopku varjenja s trenjem in mešanjem. V eksperimentalnem delu smo za zvarni spoj zlitine 2017A-T451 in 7075-T651, varjene pod različnimi pogoji, izvedli meritve hrapavosti in valovitosti ter izmerili mikrotrdoto v preseku zvarnega mesta. Nato smo poiskali povezave med izmerjenimi vrednostmi in varilnimi parametri. Izbrani vzorec smo pogledali pod mikroskopom ter opravili makro-in mikrostrukturno analizo. Najdene ekstremne vrednosti mikrotrdote smo na koncu primerjali s proučevanimi mikrostrukturnimi značilnostmi. Meritve hrapavosti so pokazale, da se nahaja največji aritmetični odstopek profila v smeri potovanja orodja, in sicer ob pogoju podajanja na obrat 25 vrt/cm pri vrednosti 5,4 µm. Najvišje vrednosti trdote so bile izmerjene pri vzorec s podajanjem na obrat 16 vrt/cm v zgornjem delu zvara v coni mešanja, in sicer pri okoli 170 HV0,2, medtem ko je bila najnižje izmerjena trdota pri istem vzorcu v spodnjem delu zvara v toplotno vplivanemu področju, in sicer na strani zvara z zlitino 7075 v vrednosti 96 HV0,2.

• Language: Slovenian
• Keywords: mikrotrdota, visokotrdnostne aluminijeve zlitine, varjenje s trenjem in mešanjem, topografija, mikrostruktura, makrostruktura
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Publisher: [U. Margon ]
• Year: 2018
• PID: 20.500.12556/RUL-103336
• UDC: 539.4.01+620.179.2(043.2)
• COBISS.SI-ID: 16235035
• Publication date in RUL: 16.09.2018

MARGON, Uroš, 2018, Mikrotrdota v zvarnih spojih raznorodnih visokotrdnostnih aluminijevih zlitin [online]. Bachelor’s thesis. U. Margon . [Accessed 31 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=103336

Secondary language

• Language: English
• Title: Microhardness in Dissimilar High-Strength Aluminium Alloy Welds

Abstract

In this study we investigated the mechanical properties of wrought aluminium alloys for transportation industry use. We focused on the strength properties, obtained by the friction stir welding process. In the experimental part, we took measurements of surface roughness and waveviness of friction stir welded joints in 2017A-4 and 7075-T6 aluminium alloys that were welded using different welding parameters. We also measured the microhardness profile through the transverse cross-section of butt joints. After finding the correlation between measured values and the welding process parameters, macroscopic and microscopic analyses for the chosen specimen were performed. Then we investigate the possible correlation between measured microhardness extremes and microstructure properties. The topography analysis showed us that the highest value of mean roughness (5,4 µm) was observed in the direction parallel to the welding direction in the area where welding process at a feed per revolution of 25 rev/cm took place. The maxima of microhardness were observed at the upper layer of the welding sample that was welded at a feed per revolution of 16 rev/cm with a value of 170 HV0,2. In the lower layer of the same specimen, the minimum of 96 HV0,2 was measured.

• Keywords: Microhardness, High-strength aluminium alloys, Friction stir welding, Topography, Microstructure, Macrostructure