Tensile creep of single phase gamma TiAl

Conference · Sat Dec 30 23:00:00 EST 1995

OSTI ID:225168

Hayes, R W ^[1]; Martin, P L ^[2]

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1. Metals Technology Inc., Northridge, CA (United States)
2. Rockwell International Corp., Thousand Oaks, CA (United States)

The uniaxial tension creep behavior of two single phase gamma TiAl alloys having the nominal compositions Ti-53Al-1Nb and Ti-51Al-2Mn (at. pct.) was studied over the temperature range 760 C to 900 C at initial applied stress levels ranging from 20.6 MPa to 345 MPa. For the Ti-53Al-1Nb alloy, two regions of creep deformation identified as either dislocation motion controlled or diffusional were found depending on the temperature and stress level. For the Ti-51Al-2Mn alloy only power law creep was observed. The tertiary creep behavior is also examined for each of these gamma TiAl alloys. Tertiary creep is evaluated using a two state-variable approach to describe the damage processes leading to an acceleration of strain rate in tertiary creep. Metallographic evaluation of failed creep specimens revealed the presence of dynamic recrystallization in the Ti-51Al-2Mn alloy. No evidence of dynamic recrystallization was found under any conditions for the Ti-53Al-1Nb alloy. These observations are related to the differences in composition and the compositional dependence of the fundamental deformation processes occurring within the minimum strain rate and tertiary creep regimens.

• OSTI ID: 225168
• Report Number(s): CONF-950201--; ISBN 0-87339-304-X
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
ACTIVATION ENERGY
AEROSPACE INDUSTRY
ALUMINIUM ALLOYS
CREEP
FORGING
GRAIN SIZE
HEAT TREATMENTS
INTERMETALLIC COMPOUNDS
MANGANESE ALLOYS
MATERIALS
MATHEMATICAL MODELS
MELTING
MICROSTRUCTURE
NIOBIUM ALLOYS
OPTICAL MICROSCOPY
RECRYSTALLIZATION
SAMPLE PREPARATION
STRAIN RATE
TEMPERATURE DEPENDENCE
TITANIUM ALLOYS
TRANSMISSION ELECTRON MICROSCOPY