Defect dragging contribution to dislocation damping in electron-irradiated high-purity polycrystalline aluminum
A study by internal friction and Young's modulus measurements were made on high-purity polycrystalline aluminum of the effects on dislocation damping by 1-Mev electron irradiation in the temperature range 78 to 360 deg K. These measurements confirm the presence of an internal friction peaking'' effect in aluminum, in agreement with the defect-dragging model proposed by Simpson and Sosin. In particular it is observed that, during electron irradiation and for specific mechanical and thermal hisiories of the sample, the logarithmic decrement delta increases and later decreases. The increase is found to be generally strain-amplitude independent and to be highly structure-dependent, disappearing after a suitable high-temperature anneal. Simultaneous modulus measurements show little or no effect due to electron irradiation between 78 and 240 deg K, but the modulus increases monotonically for irradiations above 240 deg K. The corresponding point-defect kinetics exhibit a complex annealing behavior.
- Research Organization:
- Univ. of Utah, Salt Lake City
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-29-005546
- OSTI ID:
- 4402354
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 44; ISSN JAPIAU; ISSN 0021-8979
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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