Phenomenological and microstructural analysis of room temperature creep in titanium alloys

Journal Article · Mon Apr 03 04:00:00 EDT 2000 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00426-7· OSTI ID:20020577

Neeraj, T; Hou, D H; Daehn, G S; Mills, M J

Primary creep is the dominant mode of deformation during creep of titanium alloys at room temperature. Based on a study of both Ti-6Al and Ti-6Al-2Sn-4Zr-2Mo, it is shown that the transient creep behavior can be described by a power law of the form {var_epsilon} = At{sup a}, while the strain-rate-sensitive Hollomon law, {sigma} = K{var_epsilon}{sup n}{dot {var_epsilon}}{sup m}, represents the constant strain rate behavior of titanium alloys reasonably well. A simple analytical result is derived to relate these two expressions. Using this solution, the long time creep response has been predicted reasonably well from the constant strain rate results for the two alloys studied. Relative to other metals, it is shown that titanium alloys exhibit exceptionally low values of strain hardening. Optical microscope observations of slip line evolution have been used to relate the deformation mechanisms to the macroscopic behavior. Operative slip systems, as well as dislocation distributions and morphologies, are also presented for the first time following creep of a single-phase {alpha} microstructure in Ti-6Al.

• Research Organization: Ohio State Univ., Columbus, OH (US)
• OSTI ID: 20020577
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 6 Vol. 48; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CREEP
DISLOCATIONS
MATHEMATICAL MODELS
MICROSTRUCTURE
PREDICTION EQUATIONS
SLIP
STRAIN RATE
TITANIUM BASE ALLOYS