Utjecaj temperature popuštanja na mikrostrukturu i tvrdoću CuAlNi legure s prisjetljivosti oblika

undergraduate thesis

• Author: Tomislav Polak
• Mentor: Ivana Ivanić (mentor)
• Committee member: Stjepan Kožuh (predsjednik povjerenstva)
• Committee member: Ivana Ivanić (član povjerenstva)
• Committee member: Ljerka Slokar Benić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Metallurgy; Sisak
• Defense date and country: 2022-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Metallurgy

Abstract

U ovom radu prikazan je utjecaj temperature popuštanja na mikrostrukturu i tvrdoću CuAlNi legure s prisjetljivosti oblika. Legura kemijskog sastava Cu – 12,8 Al – 4,1 Ni (mas. %) je dobivena iz tehnički čistih elemenata postupkom vertikalnog kontinuiranog lijevanja. Nakon lijevanja, dobivena šipka CuAlNi promjera 8 mm, podvrgnuta je postupku toplinske obrade koji se sastojao od kaljenja na 920 °C ' hlađenje u vodi te popuštanja na 15 °C, 200 °C, 250 °C i 300 °C '/ hlađenje u vodi. Utjecaj temperature popuštanja na mikrostrukturu CuAlNi legure utvrđen je svjetlosnom i pretražnom elektronskom mikroskopijom. Utvrđena je martenzitna mikrostruktura kod svih ispitanih uzoraka te značajni porast zrna, posebice nakon popuštanja. Tvrdoća po Vickersu pokazuje značajno povećanje tvrdoće uzorka nakon popuštanja u odnosu na kaljeno stanje.

Abstract (english)

In this paper, the influence of tempering temperature on the microstructure and hardness of CuAlNi alloy with shape memory effect is presented. Alloy with chemical composition Cu – 12.8 Al – 4.1 Ni (wt. %) was obtained from technically pure elements by the process of vertical continuous casting. After casting, the resulting CuAlNi bar with a diameter of 8 mm was subjected to a heat treatment procedure consisting of solution annealing at 920 °C / cooling in water and tempering at 150 °C, 200 °C, 250 °C and 300 °C '/ cooling in water. The influence of the tempering temperature on the microstructure of the CuAlNi alloy was determined by light and scanning electron microscopy. A martensitic microstructure was found in all tested samples and a significant grain growth was noticed, especially after tempering. The Vickers hardness shows a significant increase in the hardness of the sample after tempering compared to the annealed state.

• Keywords: legura s prisjetljivosti oblika; CuAlNi; toplinska obrada; popuštanje; mikrostruktura
• Keywords (english): shape memory alloy; CuAlNi; heat treatment; tempering; microstructure
• Language: croatian
• URN:NBN: urn:nbn:hr:115:040026
• Study programme: Title: Undergraduate study program 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
• Created on: 2022-09-08 09:10:06