Solidification microstructures and carbides morphology in rapidly solidified Fe-Al-Cr-C alloys

The combined effects of alloying additions and heat treatment on the evolution and development of the microstructures of Fe3Al-based Fe-Al-Cr-C alloys produced by melt suction processing have been examined. Particular emphasis has been placed on the distribution and morphology of carbides in rapidly solidified Fe3Al-based intermetallics. The results suggest that the formation of intrinsically hard and brittle Fe3AlC and Cr7C3 type carbides depends on the alloying content. These carbides tend to form preferentially along the grain boundaries where more continuous and coarse networks are observed, especially for alloys having higher Cr and C content. These networks are fragmented as a result of heat treatment at 1200 degrees C and subsequent air cooling and quenching.