Torsional relaxation in polycrystalline cadmium as a function of surface phenomena
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Authors
Edelson, Burton I.
Subjects
Advisors
Robertson, W.D.
Date of Issue
1953-10
Date
October 1953
Publisher
Yale University
Language
en_US
Abstract
An investigation of the tortional after-effects in polycrystalline cadmium wires which had undergone torsional plastic deformation was made. The influence of surface phenomena on relaxation rates was studied. Relaxation rates of clean wires were not influenced by the surrounding media; air, distilled water and dilute sulfuric acid. Relaxation rates of wires which had an oxide surface film were greater than those of the clean wires, and application of acid to oxidized wires caused reversals in the strain versus log time relaxation curves. Cold working caused the initial strain rate to increase; annealing prior to oxidation caused it to decrease. Increasing film thickness did not effect relaxation rate but lengthened the time during which reversal occurred. Delay in applying acid to oxidized wires increased the amount of reversal and the time for it to occur. Oxidizing the wire after twisting caused the initial strain rate to be smaller, but when acid was applied the rate became greater. The results are explained by assuming the oxide films to act as elastic, coherent jackets which modify the normal relaxation rates of the bare wires.
Type
Thesis
Description
This thesis document was issued under the authority of another institution, not NPS. At the time it was written, a copy was added to the NPS Library Collection for reasons not now known. It has been included in the digital archive for its historical value to NPS. Not believed to be a CIVINS (Civilian Institutions) title.
Series/Report No
Department
Metallurgy
Organization
Yale University
Identifiers
NPS Report Number
Sponsors
Office of Naval Research
Funder
Format
Citation
Distribution Statement
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.