| EPSRC Reference: |
GR/K03388/01 |
| Title: |
COHERENCY STRAIN AND HIGH-STRENGTH HIGH-TEMPERATURE MATERIALS |
| Principal Investigator: |
Dunstan, Professor D |
| Other Investigators: |
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| Project Partners: |
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| Department: |
Physics |
| Organisation: |
University of Surrey |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
16 January 1995 |
Ends: |
15 January 1997 |
Value (£): |
86,546
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| EPSRC Research Topic Classifications: |
| Materials Characterisation |
Materials Processing |
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| EPSRC Industrial Sector Classifications: |
| Aerospace, Defence and Marine |
Construction |
| Energy |
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Summary on Grant Application Form |
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Thin strained layers show surprisingly high elastic strains at temperatures as high as 80% of their melting points. Thick strained-layer superlattices with alternating strains (tensile and compressive) in adjacent layers are therefore predicted to retain high yield strengths to large fractions of their melting point. It is proposed to test this prediction in the model system of InGaAs grown by molecular beam epitaxy on InP substrates, in which accurate control of layer thicknesses, compositions and strains is available. Layer thicknesses will be a few tens of nanometres, with strains up to 1.5%, and the superlattice structures will be about one micron thick. They will be characterised by X-ray diffraction and transmission electron microscopy. The alternating strains are intended to prevent dislocation multiplication processes from operating, ensuring high tensile and compressive strength even at temperatures close to the melting point. Strength will be measured, firstly, by the residual stress-thickness product that the films can support. Direct tensile strength will be measured using the bulge technique, applying gas pressure to a small are of unsupported film. A bulge tester will be developed to allow tensile testing at elevated temperature. There is world-wide interest in establishing what fraction of the melting-point can be reached.
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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.surrey.ac.uk |