SEM analiza deformirane CuAlMnZr legure s prisjetiljivosti oblika

master's thesis

• Author: Dijana Knežević
• Mentor: Ivana Ivanić (mentor)
• Committee member: Mirko Gojić (predsjednik povjerenstva)
• Committee member: Ivana Ivanić (član povjerenstva)
• Committee member: Stjepan Kožuh (član povjerenstva)
• Granter: University of Zagreb; Faculty of Metallurgy; Sisak
• Defense date and country: 2023-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Metallurgy

Abstract

Legure s prisjetljivosti oblika (eng. ShapeMemoryAlloys- SMA) su vrlo važni inženjerski metalni materijali, koji su zbog svojih poboljšanih svojstava zastupljeni u brojnim područjima istraživanja.U diplomskom radu prikazana je mikrostrukturna analiza deformirane CuAlMnZr legure s prisjetljivosti oblika koja je dobivena postupkom lijevanja u grafitnu kokilu te kovanjem u šipke promjera 13 mm. Na uzorcima je provedena i toplinska obrada zagrijavanjem na 850 °C u trajanju od 30 minuta te hlađenjem u vodi do sobne temperature. Mikrostrukturna analiza lijevanog i kovanog stanja CuAlMnZr legure provedena je svjetlosnom i pretražnom elektronskom mikroskopijom, dok je mikrostrukturna analiza nakon toplinske obrade provedena pretražnom elektronskom mikroskopijom. Rezultati su pokazali da uzorci nakon kovanja posjeduju dvofaznu (α+β) mikrostrukturu, dok je nakon toplinske obrade utvrđena martenzitna mikrostruktura. Cirkonij se kao legirajući element pojavljuje u obliku uključaka što dovodi do zaključka da se nije u potpunosti homogenizirao u talini.

Abstract (english)

Shape memory alloys (SMA) are very important engineering metal materials, which are present in numerous research areas due to their improved properties. This paper presents the microstructural analysis of a deformed CuAlMnZr shape memory alloy casting into a graphite mold and forging into 13 mm diameter bars. The samples were heat treated by heating at 850 °C for 30 minutes and then cooling in water to room temperature. Microstructural analysis of the CuAlMnZr alloy in the as-cast and forged states was performed by light and scanning electron microscopy, while microstructural analysis after heat treatment was performed by scanning electron microscopy. The results showed that after forging, the samples exhibit a two-phase (α + β) microstructure, while after heat treatment, a martensitic microstructure was determined. As an alloying element, zirconium appears in the form of inclusions, suggesting that it was not completely homogenized in the melt.

• Keywords: CuAlMnZr legura s prisjetljivosti oblika; mikrostruktura; toplinska obrada
• Keywords (english): CuAlMnZr shape memory alloy; microstructure; heat treatment
• Language: croatian
• URN:NBN: urn:nbn:hr:115:046537
• Study programme: Title: Graduate study program Metallurgy; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka metalurgije (magistar/magistra inženjer/inženjerka metalurgije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-09-15 09:54:58