Screening of NiAl-base Ni-Fe-Al alloys for structural high temperature applications and development of a new Ni30Fe-10Al-Cr alloy

Various Ni-Fe-Al alloys on the basis of the intermetallic phase NiAl with B 2 structure with additional ordered or disordered Ni-rich phases were scree ned with respect to room-temperature ductility and strength at low and high temperatures up to 1100 degrees C. Alloys with combinations of NiAl and di sordered fee Ni-Fe were found to offer best possibilities for obtaining suf ficient room-temperature ductility and strength at low and high temperature s. About 25 vol.% ductile Ni-Fe phase were sufficient for a distinct improv ement of the room temperature ductility of NiAl. Further alloying with Cr f or obtaining an improved high-temperature corrosion resistance did not affe ct the advantageous mechanical properties. The development resulted in a ne w Ni-base alloy Nicrofer 6009 Al10 with 26 wt.% Fe, 10 wt.% Al, 8 wt.% Cr a nd 0.1 wt.% Hf, which is ready for application in industrial furnaces, coal conversion systems and petrochemical plants.