Analysis of strengthening mechanisms in alloys by means of thermal-activation theory
Through a systematic measurement of the strain-rate sensitivity as a function of prestrain, theoretical models of thermally activated flow are used to identify and analyze the dominant strengthening mechanisms in a number of commerical and model alloys. Several examples of the usefulness of the technique as a diagnostic tool are given. At temperatures below the plateau stress, measurements are in good agreement with predictions, even for relatively complex commercial materials, and it was demonstrated that changes in strengthening mechanisms (e.g. during age hardening or thermomechanicl processing) can be followed directly even when the scale of the microstructure is too small for convenient observation by transmission electron microscopy. Experiments at high temperature (above the regime of jerky flow) demonstrate that, except at low stress, the material behavior at moderate strain rates is dominated by strain softening mechanisms such as dislocation rearrangement by cross-slip or climb. The major effect of solution hardening at high temperature is to increase the stress at which these processes occur.
- Research Organization:
- Argonne National Lab., IL
- OSTI ID:
- 6038458
- Journal Information:
- Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 27:7; ISSN AMETA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360101 -- Metals & Alloys-- Preparation & Fabrication
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
CHROMIUM ALLOYS
COBALT
COBALT ALLOYS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA FORMS
DEFORMATION
DENSITY
DISLOCATIONS
ELEMENTS
GRAPHS
HARDENING
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HEAT TREATMENTS
INCOLOY 800
INCOLOY ALLOYS
INCONEL 600
INCONEL ALLOYS
INCONEL X750
IRON ALLOYS
IRON BASE ALLOYS
LINE DEFECTS
MAGNESIUM ALLOYS
MATERIALS
METALLURGICAL EFFECTS
METALS
NICKEL
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
PHYSICAL PROPERTIES
STRAIN RATE
TEMPERATURE DEPENDENCE
TITANIUM ALLOYS
TRANSITION ELEMENTS