Structure and properties of Fe-Al-Ti intermetallic alloys

Structure and mechanical properties of Fe-Al-Ti alloys in the composition r ange Fe-(10 27.5) wat.%Al-(10-30) at.%Ti have been studied. The alloys exhi bited a wide range of microstructure comprising alpha -Fe, Fe2Ti (Laves pha se) and/or Fe2AlTi (Heusler phase) depending on the composition. Their room temperature hardness, Young's modulus, ratio of plastic to elastic work an d yield strength were determined. Elevated temperature yield strength and c reep properties of these alloys were also studied. It was observed that sig nificant increase in strength and hardness may be achieved in alloys contai ning two or more phases. The compressive creep behaviour of these alloys fo llowed the power law in creep in the temperature range 873-1073 K. Creep st ress exponents in the range 3-6 were observed, suggesting dislocation creep to be the operative mechanism. Apparent activation energy for creep was fo und to be in the range of 400 to 600 KJ/mol. (C) 2001 Elsevier Science Ltd. All rights reserved.