Masters Theses

Abstract

"Sintering studies on a commercial natural magnesite have been done to investigate the influence of MnO doping (MnO concentration from 0.16 to 2.50 wt.%) on the densification process over the temperature range 1520 to 1760°C , over periods of time from 3,600 to 57,600s in both oxidizing and reducing atmospheres (Air and PO2 = 10-7 KPa. In an air atmosphere the additions of MnO enhances the densification process. This fact may be associated with an increase in lattice diffusion of Mg ions due to an increase in cation vacancies in the MgO lattice from the presence of Mn+3.Under reducing conditions MnO additions do not effect densification, which may be due to the minimization of cation defects since Mn should be in the +2 oxidation state. In air, sintering temperature was found to be more important than time. On the other hand, under reducing conditions little densification occurred for temperatures greater than 1640°C. This appears to be associated with an evaporation process which tends to suppress the densification rate"--Abstract, page ii.

Advisor(s)

Anderson, H. U. (Harlan U.)

Committee Member(s)

Leighly, Hollis P., 1923-2004
Moore, Robert E., 1930-2003

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Ceramic Engineering

Comments

The author is very grateful to the company MAGNESITA SA of Brazil for financial support during the course of this investigation.

Publisher

University of Missouri--Rolla

Publication Date

Spring 1982

Pagination

xiii, 149 pages

Note about bibliography

Includes bibliographical references (pages 128-141).

Rights

© 1982 Alamar Kasan Duarte, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 4809

Print OCLC #

8691570

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