Modelling the strain rate sensitivity of strain aging alloys

Journal Article · Sun Aug 01 00:00:00 EDT 1993 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(93)90501-I· OSTI ID:6138271

Schlipf, J ^[1]

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1. Inst. fuer Metallkunde und Metallphysik, Aachen (Germany)

It is generally accepted that dislocation motion during plastic deformation is non-uniform. The glide dislocations are held up at major obstacles (viz. forest dislocations) where they form a junction while waiting for thermal activation. In a solid solution additional pinning may take place during the waiting time due to rearrangement of solutes in the vicinity of the glide dislocation (dynamic strain aging, DSA). Two pinning mechanisms are currently discussed: in lineal pinning solutes from the bulk move into binding positions at the dislocation core, and in the case of forest strengthening solutes move via pipe diffusion to the junction where they contribute to the strength of the barrier. In both cases diffusion is accelerated due to drift in the stress field of the glide dislocation. If DSA is active, the strain rate sensitivity (SRS) as measured in a strain rate change test strongly decreases and may even become negative. When a critical negative value of the SRS is exceeded plastic instabilities occur. It is the purpose of the present paper to provide a simple model for the behavior of the SRS as observed in experiments on strain aging.

• OSTI ID: 6138271
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 29:3; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
AGING
ALLOYS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DEFORMATION
DIFFUSION
DISLOCATIONS
DISPERSIONS
LINE DEFECTS
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MIXTURES
PLASTICITY
SOLID SOLUTIONS
SOLUTIONS
STRAIN AGING
STRAIN RATE