Ferritische Hochtemperaturlegierungen

Iron-aluminium-based alloys with a ferritic matrix are potential candidates for high temperature applications because of their low density, good thermal conductivity and their good corrosion as well as oxidation behaviour at high temperatures. The matrix can be present as a disordered A2 α-(Fe,Al)-, an ordered B2 α2-FeAl- or an ordered D03 Fe3Al-crystal structure, depending on the chemical composition of the alloy. In case of a matrix with disordered A2 crystal structure thermal activated processes occur relatively fast, thus leads insufficient tensile and creep strength at elevated temperature. There are several mechanisms to improve the mechanical properties, i.e. precipitation hardening, especially hardening with incoherent Laves-Phases. Literature research about the current state of the art of iron-aluminium-based alloys as well as the microstructural characterisation of various experimental alloys have been done within this work.