EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Fe-Al intermetallic alloys display interesting properties for applications at high temperatures, including excellent mechanical strength and good oxidation resistance. Moreover, their cost is attractive, and they present weight reduction compared to other iron-based alloys. However, their low ductility at room temperature prevents them to be implemented industrially by simple routes such as conventional casting. The present experimental approach considers improving their ductility by the addition of copper as alloying element. This element has been selected not only because it is an element that would promote the precipitation of ductile Cu precipitates so as to eventually improve the overall ductility, but also because the ternary Fe-Al-Cu is poorly studied in the Fe-Cu rich region and may feature interesting microstructures. For that purpose, the present study focuses on 3 different grades of Fe-28 at.% Al-X at.% Cu (X=15 at.%, 20 at.%, 25 at.%) obtained either by cold crucible induction melting or conventional ingot casting. The microstructures obtained as cast and after different heat treatments have been characterized using SEM, EDX and XRD (laboratory and synchrotron source), and their mechanical response has been evaluated thanks to hardness and tensile tests. Because ductility did not improve significantly, we have also investigated quaternary and quinary alloys, adding Cr and Ni.