Effects of Grain Size and Purity on the Low Temperature Cyclic Strain Degradation of Stabilizer Aluminum

  • L. Clark McDonald
  • K. Ted Hartwig
  • H. Zou
Part of the Advances in Cryogenic Engineering Materials book series (ACRE, volume 42)

Abstract

Aluminum specimens of 99.99% to 99.9998% purity and with grain sizes ranging from 0.1 mm up to 2.2 mm have been mechanically and electrically tested at 4.2 K to determine strain hardening and resistivity degradation characteristics. RRR values of the fully annealed (large grained) materials range from 1,150 up to 10,400. Results show that for a cyclic strain range of ±0.001 at 4.2 K, the effects of grain size are significant when purities are greater than about 99.9995%. At purities below 99.999%, the grain size has a minimal effect on the rate of strain hardening and on resistivity degradation. Mechanisms for the observed behavior are associated with increased strain hardening rates and a reduction in the total number of point defects (vacancies) generated during the low temperature deformation.

Keywords

Flow Stress Strain Range Cyclic Strain High Purity Aluminum Aluminum Specimen 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • L. Clark McDonald
    • 1
  • K. Ted Hartwig
    • 1
  • H. Zou
    • 1
  1. 1.Mechanical Engineering DepartmentTexas A&M UniversityCollege StationUSA

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