Vpliv hitrosti deformacije na dolžino stiskalniškega ostanka med iztiskavanjem aluminijeve zlitine EN AW-6082 : magistrsko delo

Mlinar, Timotej (author), Fajfar, Peter (mentor), Cvahte, Peter (comentor)

Aluminijevo zlitino EN AW-6082 odlikujejo visoka trdnost, odlična korozijska odpornost in dobra varivost, zaradi česar so izdelki omenjene zlitine široko uporabni v transportni in gradbeni industriji. Globalizacija in dinamika trga narekujeta časovno verigo od naročnika do dobavitelja, ki strmijo k visoki zmogljivosti in kakovosti, čigar izdelek je odvisen od izmeta in optimizacije dela. V magistrskem delu je bil obravnavan vpliv hitrosti deformacije na dolžino stiskalniškega ostanka med procesom vročega iztiskovanja aluminijeve zlitine EN AW-6082. Preizkušanje je potekalo z iztiskavanjem palice, premera 80 mm, pri povprečni hitrosti pomika bata 9 mm?s-1, 9,5 mm?s-1, 10 mm?s-1, 10,16 mm?s-1 in 11 mm?s-1. Rezultati mehanskih preizkusov so pokazali odstopanja mehanskih lastnosti med začetkom in koncem iztiskavanih palic. Med tem, ko se mehanske lastnosti konca palice približujejo nominalnim vrednostim, je vpliv napak v začetku previsok, kar se odraža pri nižjih trdnostnih lastnostih. Metalografska analiza je na mestih z najnižjimi mehanskimi lastnostmi potrdila prisotnost nehomogenega mešanja materiala in vsebnost oksidnih vključkov različnih velikosti. Eksperimentalni del je bil podprt z računalniškimi simulacijami iztiskavanja po metodi končnih elementov, kjer so bile spremljane veličine razvoja temperature, tok materiala in hitrosti deformacije pri vseh petih različnih hitrostih iztiskavanja. Rezultati simulacij in metalografske analize so pokazali vpliv hitrosti pomika bata na smer tokovnic materiala, temperaturni profil in dolžino dosega notranjih napak.

• Language: Slovenian
• Keywords: Aluminijeva zlitina, EN AW-6082, vroče iztiskavanje, stiskalniški ostanek, simulacija.
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Place of publishing: Ljubljana
• Publisher: T. Mlinar
• Year: 2023
• Number of pages: XV, 52 f.
• PID: 20.500.12556/RUL-151103
• UDC: 669
• COBISS.SI-ID: 167899907
• Publication date in RUL: 29.09.2023

MLINAR, Timotej, 2023, Vpliv hitrosti deformacije na dolžino stiskalniškega ostanka med iztiskavanjem aluminijeve zlitine EN AW-6082 : magistrsko delo [online]. Master’s thesis. Ljubljana : T. Mlinar. [Accessed 14 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=151103

Secondary language

• Language: English
• Title: Effect of strain rate on length of discard during extrusion of aluminium alloy EN AW-6082 : master's thesis

Abstract

Aluminium alloy EN AW-6082 is characterized by high strength, excellent corrosion resistance and good weldability, which makes the products of the mentioned alloy widely applicable in the transport and construction industries. Globalization and market dynamics dictate the time chain from the client to the supplier, which strives for high performance and quality, whose product depends on the ejection and optimization of work. In the master's thesis, the influence of the deformation rate on the length of the press residue during the hot extrusion process of the aluminium alloy EN AW-6082 was discussed. The test was carried out by extruding a bar with a diameter of 80 mm, at an average speed of ram movement of 9 mm⠙s-1, 9.5 mm⠙s-1, 10 mm⠙s-1, 10.16 mm⠙s-1 and 11 mm⠙s-1. The results of the mechanical tests showed deviations of the mechanical properties of the beginning and end of the extruded bars. While the mechanical properties of the rod end approach the nominal values, the influence of defects is initially too high, which is reflected in the lower strength properties. Metallographic analysis confirmed the presence of inhomogeneous mixing of the material and the content of oxide inclusions of different sizes at the places with the lowest mechanical properties. The experimental part was supported by computer simulations of extrusion using the finite element method, where the temperature development, material flow and deformation rate were monitored at all five different extrusion speeds. The results of simulations and metallographic analysis showed the influence of ram movement speed on the direction of the material flow, temperature profile and the length of the reach of internal defects.

• Keywords: Aluminium alloy, EN AW-6082, hot extrusion, extrusion discard, simulation.