Microscopy analysis of Cu-Al-Mn alloy microalloyed with titanium

U ovom radu provedena je mikroskopska analiza (optička mikroskopija, pretražna elektronska mikroskopija i energetsko disperzijska spektrometrija) i ispitivanje tvrdoće Cu-9Al-7Mn legure mikrolegirane s titanom (0,4 mas.%). Analiza je provedena za leguru u lijevanom stanju (ingot) i nakon toplinske obrade (900 oC/30 min/ H2O). Legura je pripremljena iz čistih elemenata istaljenih u elektrolučnoj vakumskoj peći pod zaštitnom atmosferom argona. Nakon lijevanja u kalup provedena je toplinska obrada (kaljenje) i metalografska priprema. Mikrostrukturna karakterizacija provedena je optičkom mikroskopijom i pretražnom elektronskom mikroskopijom (SEM) s energetsko disperzijskom spektrometrijom (EDS). Temperatura faznih prijelaza ispitivana je diferencijalno pretražnom kalorimetrijom (DSC). Tvrdoća uzoraka u lijevnom i kaljenom stanju mjerena je Vickersovom metodom. U lijevanom uzorku nije utvrđena prisutnost martenzitne faze, dok je nakon toplinske obrade utvrđena prisutnost martenzitne faze. Temperature faznih prijelaza nisu vidljive na krivulji prilikom ispitivanja DSC analizom od sobne temperature do 300 oC. Nakon toplinske obrade došlo je do značajnog povećanja tvrdoće legure.In this paper microscopy analysis (optical microscopy, scanning electron microscpy and energy dispersion spectrometry) and hardness testing was carried out of Cu-9Al-7Mn alloy microalloyed with titanium (0.4 wt.%). Analysis was performed in as-cast state and after heat treatment (900 oC/30 min/ H2O). Alloy was prepared from pure metals in vacum electroarc furnace under the protective argon atmosphere. The heat treatment and metalographic preparation was performed after casting. Optical and scanning electron microscopy (SEM) with energy dispesion spetrometry (EDS) was used for microstructural analysis. Diferential scanning calorimetry was used for measuring temperatures of phase transformations. For hardness of samples in as-cast and as-quenched state Vickers method was used. In as-casted sample martensite phase was not detected, while after heat treatment martensite phase was detected. Phase transformation temperatures were not visible od the DSC curve measured from room temperature to 300 oC. After heat treatment significant increase in hardness of analyzed alloy was observed