Doctoral Dissertations

Abstract

"The age hardening processes in Mg-3.5 wt.% Th-1.0 wt.% Mn and Mg-1.0 wt.% Th-1.0 wt.% Mn alloys have been studied by light and electron microscopy, and by electron and X-ray diffraction. At aging temperatures of 300ºC and below, G.P. zone formation rapidly hardens these alloys followed by the precipitation of disc shaped plates during averaging. During aging above 300ºC, no G.P. zones form and the disc shaped precipitate grows to very large sizes. The combined results of X-ray and electron diffraction indicate that the disc shaped precipitate has a Mg₃Cd (DO₁₉) type structure. The basal plane of the Mg₃Th discs lie parallel to the matrix basal plane which is also the habit plane of this precipitate. Basal slip and {101̄2} twinning, the principal deformation modes, shear the G.P. zones but not the Mg₃Th discs"--Abstract, page iii.

Advisor(s)

Clark, J. B. (J. Beverley)

Committee Member(s)

Weart, H. W. (Harry Waldron), 1927-
Leighly, Hollis P., 1923-2004
Straumanis, Martin E., 1898-1973
Moore, Robert E., 1930-2003

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Metallurgical Engineering

Publisher

University of Missouri--Rolla

Publication Date

1971

Pagination

viii, 29 pages

Note about bibliography

Includes bibliographical references (page 17).

Rights

© 1971 Kuldip Singh Chopra, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

Magnesium alloys -- Testing
Hardness -- Testing
Metals -- Hardness
Magnesium alloys -- Microstructure

Thesis Number

T 2612

Print OCLC #

6038177

Electronic OCLC #

874906804

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Metallurgy Commons

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