Creep of a fine-grained, fully-lamellar, two-phase TiAl alloy at 760{degree}C

Technical Report · Tue Jan 31 23:00:00 EST 1995

DOI:https://doi.org/10.2172/46701· OSTI ID:46701

Wang, J N; Schwartz, A J; Nieh, T G ^[1]; Liu, C T; Sikka, V K ^[2]; Clemens, D ^[3]

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1. Lawrence Livermore National Lab., CA (United States)
2. Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)
3. Pratt-Whitney, United Technologies, Jupiter, FL (United States)

Creep of a TiAl alloy, having a composition of Ti-47Al-2Cr-2Nb (in atom %) and a fine-grained, fully-lamellar structure, was carried out at 760 C and stresses between 69--723 MPa. It was found that, in addition to having good room temperature properties, the alloy exhibits higher creep resistance than other TiAl alloys with a similar composition. Both the creep data and microstructures of the alloy suggest that there exists a change in deformation mechanism from a glide-controlled process at high stresses to a recovery-controlled process at low stresses. Also, microstructural evidence indicates that the rate-controlling recovery mechanism is the climb of dislocation segments pinned by ledges at {gamma}/{alpha}{sub 2} interfacial boundaries.

• Research Organization: Lawrence Livermore National Lab., CA (United States); Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48; AC05-84OR21400
• OSTI ID: 46701
• Report Number(s): UCRL-JC--119681; CONF-950201--11; ON: DE95009531
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CHROMIUM ALLOYS
CREEP
EXPERIMENTAL DATA
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
NIOBIUM ALLOYS
QUATERNARY ALLOY SYSTEMS
TITANIUM ALLOYS