| EPSRC Reference: |
GR/J36815/01 |
| Title: |
FATIGUE CRACK GROWTH IN NI-BASED SUPERALLOY SINGLE CRYSTALS: MECHANISMS AND MODELLING |
| Principal Investigator: |
Martin, Dr J |
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| Department: |
Materials |
| Organisation: |
University of Oxford |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
01 April 1994 |
Ends: |
31 March 1997 |
Value (£): |
163,882
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| EPSRC Research Topic Classifications: |
| Materials Characterisation |
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Summary on Grant Application Form |
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The aim is to gather the data needed to develop a predictive model for fatigue crack growth, concentrating on the near-threshold stage I regime (which occupies the greatest part of the fatigue-limited operational lifetime) and to construct such a model. This model will be based on our successful model of the BDT, where the dynamics of dislocation motion around the crack tip are simulated. Two materials will be examined: a single crystal, single phase alloy (Cu/Al), and a commercial single crystal aerofoil alloy (CMSX-4). Specimens will be oriented for single slip, and tested in fatigue under near-threshold conditions. Tests will be interrupted, and the structure of the crack tip process zone will be characterised by TEM and by SEM channelling imaging. Data will be gathered on the variation with temperature, stress, frequency, etc of: a) the magnitude of the crack extension when the critical stage is reached; b) the number and amplitude of the strain cycles required for a single crack extension increment; c) the density and distribution of the dislocations within the process zone. The ultimate aim of the work is to develop the model, so that the essential behaviour of the crack tip plastic zone in cyclic loading can be understood, with a view to giving guidance to alloy development and for use in life prediction.
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
| Summary |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.ox.ac.uk |