Importance of microstructural stability in creep resistance of lamellar TiAl alloys

Creep behavior of lamellar Ti-45Al-8Nb-0.2C (in mol%) alloy was studied paying special attention to microstructural degradation during creep. Minimum creep rate of Ti-45Al-Nb-C is reduced to 25% of that of binary Ti-45Al. Nb retards recovery of dislocations. Nb and C addition stabilizes lamellar microstructure. As a result, lower minimum creep rate and slower creep acceleration in tertiary creep are attained in the TiAl alloy with Nb and C. (C) 2007 Elsevier B.V. All rights reserved.