diplomsko delo
Tomaž Ulčar (Author), Milan Bizjak (Mentor)

Abstract

Z razvojem tehnologije narašča povpraševanje po »pametnih« materialih, ki so se sposobni aktivno odzvati na spremembe zunanjih pogojev (temperature, magnetnega polja, itd.) in pri tem celo opraviti neko delo. Mednje spadajo tudi zlitine s spominom oblike. To so materiali, ki si zapomnijo kako so bili oblikovani predno smo jih deformirali in se bodo pri segrevanju/ohlajanju povrnili v prvotno obliko brez uporabe zunanjih sil. Pogoj za nastanek oblikovnega spomina je kristalografsko reverzibilna martenzitno – avstenitna transformacija, katere potek zasledujemo s pomočjo določevanja temperatur začetka in konca transformacije med ohlajanjem (Ms in Mf) ter segrevanjem (As, Af). V diplomskem delu smo analizirali vpliv termičnega cikliranja na spremembo karakterističnih temperatur martenzitno - avstenitne transformacije zlitine Cu-Al-Mn. Vzorce v obliki tankih trakov smo izdelali po metodi prostega strjevanja na vrtečem se valju. Spremembo karakterističnih temperatur martenzitno - avstenitne transformacije med termičnim cikliranjem smo zasledovali s pomočjo natančnih in-situ meritev spremembe električne upornosti. Hkrati smo spremljali tudi spremembo mikrostrukture te zlitine s primerjavo in analizo mikrostruktur vzorcev pred in po termičnem cikliranju. Karakterizacijo mikrostrukture smo opravili s svetlobnim (SM) in elektronskim vrstičnim mikroskopom (SEM), s katerim smo izvedli tudi mikrokemično analizo mikrostrukturnih sestavin z metodo energijske disperzne spektroskopije (EDS).

Keywords

zlitine s spominom oblike;Cu-Al-Mn;avstenitno - martenzitna fazna transformacija;meritve električne upornosti;temperature faznih transformacij;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL NTF - Faculty of Natural Sciences and Engineering
Publisher: [T. Ulčar]
UDC: 669
COBISS: 1843295 Link will open in a new window
Views: 595
Downloads: 160
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Other data

Secondary language: English
Secondary title: effect of thermal cycling on the reverse martensitic phase transformation of CuAlMn shape memory alloy
Secondary abstract: With the development of technology, the demand for "smart" materials, capable of actively respond to external influence (temperature or magnetic field, etc.) and even doing some work, has been increasing. These materials also include shape memory alloys, which remember how they were shaped before we deformed them and, when heated or cooled, will return to their original form without the use of external forces. The condition for the formation of shape memory effect is the crystallographically reversible martensitic - austenitic transformation, that can be followed by measuring the start and end temperatures of the transformation during cooling (Ms and Mf) or heating (As, Af). In the diploma work, we studied the influence of thermal cycling on the change of the characteristic temperatures of the martensitic-austenitic transformation of Cu-Al-Mn alloy. Samples in the form of thin ribbons were produced by the melt spinning method. The change in the characteristic temperatures of the martensitic-austenitic transformation during thermal cycling was followed by accurate in-situ measurements of the change in electrical resistance. At the same time, we also monitored the change in the microstructure of the alloy by comparing and analyzing the microstructures of samples before and after thermal cycling. Characterization of the microstructure was performed by light and electron scanning microscope (SEM), equipped with the energy dispersive spectrometer (EDX).
Secondary keywords: shape - memory alloys;Cu-Al-Mn;austenitic - martensitic phase transformation;electrical resistivity measurements;phase transformation temperatures;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Naravoslovnotehniška fak., Odd. za materiale in metalurgijo
Pages: XII, 33 f.
ID: 11238015