Masters Theses

Abstract

"A Unitron hot stage and polarized light were used to enable direct observation of recrystallization in high purity (99.99 per cent) zinc and high zinc content alloys. Electrolytic polishing was investigated in an attempt to prepare unetched surfaces which would show good structural contrast under polarized light and thus permit structural changes occurring during recrystallization to be observed.

Kinetic data obtained from a sequence of photographs during each recrystallization trial showed typical sigmoidal isothermal reaction curves characteristic of a nucleation and growth process. It was determined that rates of nucleation and grain growth are a maximum over the same time interval that isothermal recrystallization rates show a maximum.

Grain growth rates were found to be irregular and to vary considerably for different grains of the same sample.

Orthophosphoric-ethyl alcohol solutions were the only electrolytes found which would give polished surfaces free of preferential attack at grain or twin boundaries. Operating voltages determined the contrast obtained when viewing the polished surface under polarized light. Current density was important in preventing etching and pitting"--Abstract p. ii

Advisor(s)

Hollis P. Leighly, Jr.

Committee Member(s)

William A. Frad
G. Edwin Lorey
Wilbur P. Tappmeyer

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Metallurgical Engineering

Publisher

Missouri School of Mines and Metallurgy

Publication Date

1963

Pagination

vi, 75 pages

Note about bibliography

includes bibliographical references (page 74)

Rights

© 1963 Roy Ashley Smith, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 1456

Print OCLC #

5950337

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