A microstructural investigation of the shear distortions and energetics of motions observed in an aged high damping 53Cu-45Mn-2Al alloy

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Authors
Farkas, David Michael
Subjects
High damping
Cu-Mn
Cu-Mn-Al
Tweed microstructure
Flickering
Image extinctions
Energetics
Chaotic activity
Advisors
Perkins, Jeff
Date of Issue
1989-03
Date
March 1989
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
The shear distortions developed upon aging of a 53Cu-45 Mn-2Al alloy were studied using transmission electron microscope image extinctions and diffraction spot streak analysis. It was determined that a lattice distortion of (110) planes, in 111 directions developed in the alloy as aging progressed. This matured 111 shear induces a distinct V-shaped contrast which displays dynamic motion under the electron-beam irradiation of TEM examination. Video imaging techniques were applied to this activity, termed 'flickering', to investigate the energetics of the underlying crystalline lattice motion. The real-time behavior at the flicker sites suggests that the underlying mechanism which produces the dynamic contrast change is a gradual crystallographic transition, typical of a second-order phase transition.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
107 p.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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