Microstructural characterisation of casted ingot of the CuAlMn alloy

U ovom radu provedena je mikrostrukturna karakterizacija CuAlMn legure s prisjetljivosti oblika. Ispitivanje je provedeno na uzorcima legure u lijevanom i toplinski obrađenom stanju. Ispitivana legura dobivena je taljenjem tehnički čistih elemenata bakra, aluminija i mangana ciljanog kemijskog sastava Cu – 8.6%, Al – 9,9% Mn (mas.%). Toplinska obrada uzorka provedena je na temperaturi od 900 °C u vremenskom periodu od 15 minuta nakon čega je usljedilo hlađenje vodom. Mikrostrukturna karakterizacija CuAlMn legure provedena je optičkom mikroskopijom i pretražnom elektronskom mikroskopijom opremljenom s energetsko disperzijskim spektrometrom. Rezultati su pokazali da uzorci posjeduju dvofaznu (α + β) mikrostrukturu u lijevanom stanju, dok je nakon toplinske obrade zamijećena samo martenzitna mikrostruktura. Provedeno je ispitivanje mikrotvrdoće Vickersovom metodom te rezultati pokazuju veću tvrdoću nakon toplinske obrade.In this research a microstructural characterisation of CuAlMn shape memory alloy has been performed. The research was performed on alloy samples in as-cast and heat treated state. The tested alloy was obtained by melting technically pure elements of copper, aluminium and manganese with a targeted chemical composition of Cu – 8.6%, Al – 9,9% Mn (wt.%). The heat treatment of the sample was carried out at a temperature of 900 °C for a period of 15 minutes after which it was cooled with water. Microstructural characterization of the CuAlMn alloy was performed by optical microscopy and scanning electron microscopy equipped with an energy dispersion spectrometer. The results showed that the sample had a two – phase (α + β) microstructure in as-cast state while after heat treatment only a martensitic microstructure was observed. Microhardness testing was performed using the Vickers method and the results show higher hardness after heat treatment