Mikrostrukturna karakterizacija CuAlMn trake s prisjetljivosti oblika

undergraduate thesis

• Title (english): Microstructural characterization of CuAlMn shape memory ribbon
• Author: Ivan Bogeljić
• Mentor: Stjepan Kožuh (mentor)
• Committee member: Mirko Gojić (predsjednik povjerenstva)
• Committee member: Stjepan Kožuh (član povjerenstva)
• Committee member: Tamara Holjevac-Grgurić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Metallurgy; Sisak
• Defense date and country: 2016-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Metallurgy; Physical Metallurgy

Abstract

Zbog svojih dobrih svojstava, posebice duktilnosti, CuAlMn slitine s prisjetljivosti
oblika bi mogle imati široku tehničku primjenu. U ovom radu je prikazana mikrostrukturna
analiza CuAlMn slitine s prisjetljivosti oblika nakon taljenja (ingot) i lijevanja (brzo skrutnuta
traka). Slitina kemijskog sastava Cu – 8,96% Al – 7,08 % Mn (mas. %) je pripremljena iz
čistih metala a potom i lijevana tehnikom „melt spinning“ u inertnoj atmosferi argona.
Najprije je dobiven ingot mase 684 g i dimenzija ø45x55 mm koji je korišten kao ulazni
materijal za lijevanje. Mikrostruktura slitine analizirana je optičkom mikroskopijom i
pretražnom elektronskom mikroskopijom. Također, mjerenjem električnog otpora
ustanovljene su mikrostrukturne promjene u brzoskrutnutim trakama. Metalografska analiza
ingota je potvrdila postojanje dvofazne mikrostrukture (α+ β), dok je u brzo skrutnutim
trakama zamijećeno postojanje martenzita. Rezultati mjerenja električnog otpora i DSC
analiza pokazuju faznu transformaciju koja može biti povezana s formiranjem precipitata
ravnotežne α– faze i sređivanja austenitne strukture.

Abstract (english)

Because of their good characteristics, especially ductility, CuAlMn shape memory
alloys could have wide application in engineering. In this paper, microstructural analysis of
CuAlMn shape memory alloys after smelting (ingot) and casting (rapidlysolidified ribbon) is
shown. Alloy with the chemical composition of Cu – 8.96 Al – 7.08 %Mn (wt. %) was
prepared from pure metals and then the alloy was casted by melt spinning tehnique, under
inert argon atmosphere. The prepared ingot weight was 684 g and dimensions of ø45x55 mm
and it was used as an input material for casting. The microstructure of the alloy was analysed
with optical microscopy and scanning electron microscopy. Also, by measuring the electrical
resistance in the rapidly solidified ribbons, the microstructural changes were determined.
Metallographic analysis of ingot confirmed the existence oftwo-phase microstructure (α+ β),
while rapidly solidified ribbons substantiate the existence of martensite. Measurements of the
electrical resistance showed a phase transformation which canbe associated with the
formation of precipitates of the equillibrium α– phase and with order – disorder transition of
austenite.

• Keywords: CuAlMn; slitine s prisjetljivosti oblika; martenzit; „melt spinning“ postupak; toplinska analiza
• Keywords (english): CuAlMn; shape memory alloys; martensite; melt spinning tehnique; thermal analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:115:623595
• Project: Number: IP-2014-09-3405; Title: Dizajniranje mikrostrukture i funkcionalnih svojstava legura s prisjetljivosti oblika na bazi bakra; Acronym: DMFP-CuSMA; Leader: Mirko Gojić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Metallurgy; specializations in: Metallurgical Engineering, Industrial Ecology; Course: Metallurgical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka metalurgije (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka metalurgije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Public note: Ovaj je rad financirala Hrvatska zaklada za znanost projektom IP-2014-09-3405.
• Created on: 2016-09-30 09:07:02