Effect of Carbon and Titanium Additions on Mechanical Properties of B2 FeAl

Iron aluminides based on Fe3Al and FeAl are highly oxidation and corrosion resistant and have potential for elevated temperature structural applications. Carbon is an important alloying element in Fe3Al as it increases strength and creep resistance as well as resistance to environmental embrittlement. However, addition of carbon to FeAl has not been successful as it leads to precipitation of graphite which causes decrease in strength. Graphite formation can be prevented by the addition of titanium (Ti) which forms TiC in the FeAl matrix. Ti addition imparts strength to FeAl alloys containing carbon without loss of room temperature ductility. Observed mechanical properties have been related with the microstructure. Up to 75 % increase in elevated temperature yield strength is obtained at target service temperature (923 K). This can lead to successful development of carbon containing FeAl based alloys for elevated temperature structural applications.