High temperature thermo-mechanical stability of lamellar ({gamma} + {alpha}{sub 2}) Ti-49Al-2V

Book · Sun Dec 31 00:00:00 EST 1995

OSTI ID:225085

Guillard, S ^[1]; Rack, H J ^[2]

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1. Concurrent Technologies Inc., Johnstown, PA (United States)
2. Clemson Univ., SC (United States)

The high temperature thermo-mechanical stability of lamellar two phase {gamma} + {alpha}{sub 2} Ti-49Al-2V has been examined. At low temperatures and high rates the flow behavior exhibited initial strain hardening, followed by flow softening and steady-state behavior at high strains. As the temperature increased and/or the strain rate decreased, strain hardening was eliminated, flow softening commencing upon yielding. Dynamic material modeling showed that two stable flow regions exist in this alloy and microstructural condition, both stable regimes being associated with dynamic spheroidization of the lamellar {gamma} + {alpha}{sub 2} structure. At higher temperatures and lower rates, dynamic spheroidization involved both the {gamma} and {alpha}{sub 2} lamellae, while at lower temperatures and/or higher rates the {alpha}{sub 2} lamellae remained essentially unchanged, all deformation occurring within the {gamma} phase. Finally, unstable flow is related to lamellae kinking, flow localization and surface cracking.

• OSTI ID: 225085
• Report Number(s): CONF-950201-; ISBN 0-87339-304-X; TRN: IM9621%%15
• Resource Relation: Conference: Annual meeting and exhibition of the Minerals, Metals and Materials Society (TMS), Las Vegas, NV (United States), 12-16 Feb 1995; Other Information: PBD: 1995; Related Information: Is Part Of Gamma titanium aluminides; Kim, Y.W. [ed.] [UES, Inc., Dayton, OH (United States). Materials and Processes Div.]; Wagner, R. [ed.] [GKSS Research Center, Geesthacht (Germany). Inst. for Materials Research]; Yamaguchi, Masaharu [ed.] [Kyoto Univ. (Japan). Dept. of Materials Science and Engineering]; PB: 1023 p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
33 ADVANCED PROPULSION SYSTEMS
TITANIUM ALLOYS
MICROSTRUCTURE
PLASTICITY
ALUMINIUM ALLOYS
VANADIUM ALLOYS
GAS TURBINE ENGINES
MATERIALS
INTERMETALLIC COMPOUNDS
STRAIN HARDENING
FLOW STRESS
LAMELLAE
STRAIN RATE
OPTICAL MICROSCOPY
TRANSMISSION ELECTRON MICROSCOPY
TEMPERATURE DEPENDENCE
ACTIVATION ENERGY
EXPERIMENTAL DATA