Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

The influence of microstructure on creep deformation in {gamma} TiAl

Book ·
OSTI ID:225167
 [1];  [2];  [3]
  1. Wright Lab., Wright-Patterson AFB, OH (United States)
  2. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Material Science
  3. Ford Motor Co., Dearborn, MI (United States)

The influence of microstructure on creep deformation has been examined in two {gamma} TiAl alloys, Ti-49Al-1V-0.07C and Ti-48Al-1V-0.3C. Microstructure was shown to have a significant influence on the creep behavior of these alloys, with a fully lamellar microstructure having the highest creep resistance. Overall creep resistance was influenced by the volume fraction of lamellar constituent, with the lowest creep resistance observed at intermediate lamellar volume fractions. The decrease in creep resistance of the duplex microstructure, compared to the near-{gamma} microstructure is explained by an increase in dislocation mobility within the equiaxed {gamma} constituent. The high creep resistance of the fully lamellar microstructure is attributed to the fine spacing of the lamellar structure, which results in a decreased slip length for dislocation motion. Significant improvement in creep resistance was observed in the high carbon alloy compared with the Ti-49Al-1V-0.07C alloy. The formation of sub-boundaries is inhibited with the addition of carbon in the duplex microstructure. These findings suggests that solute/dislocation interaction mechanisms may be responsible for the significant increase in creep resistance observed with the addition of carbon.

OSTI ID:
225167
Report Number(s):
CONF-950201--; ISBN 0-87339-304-X
Country of Publication:
United States
Language:
English