Structure and properties of Fe–Al–Ti intermetallic alloys

Structure and mechanical properties of Fe–Al–Ti alloys in the composition range Fe–(10–27.5) at.%Al–(10–30) at.%Ti have been studied. The alloys exhibited a wide range of microstructure comprising α-Fe, Fe2Ti (Laves phase) and/or Fe2AlTi (Heusler phase) depending on the composition. Their room temperature hardness, Youngʹs modulus, ratio of plastic to elastic work and yield strength were determined. Elevated temperature yield strength and creep properties of these alloys were also studied. It was observed that significant increase in strength and hardness may be achieved in alloys containing two or more phases. The compressive creep behaviour of these alloys followed the power law in creep in the temperature range 873–1073 K. Creep stress exponents in the range 3–6 were observed, suggesting dislocation creep to be the operative mechanism. Apparent activation energy for creep was found to be in the range of 400 to 600 KJ/mol.