Doctoral Dissertations

Abstract

"The validity of ideal barrier layer diffusion kinetics was examined in the NaCl/KCl - glycerol and Al2O3-CaO-Al2O3-SiO2/slag corrosion systems. Single crystals and dense polycrystalline plates of pure NaCl or KCl exhibit steady-state corrosion rates within 10%, of calculated theoretical values, while dense mixtures of the two salts corrode at rates higher than either pure material. The results are compared to the grooving phenomena of NaCl/KCl bicrystals.

Polycrystalline Al2O3 is shown to corrode at the same rate as single crystal sapphire at 1400°C in CaO-SiO2-Al2O3 slag, while at 1450° c intergranular attack causes an increase in K', the steady-state corrosion rate. Small CaO additions (0.009m%, to 0.90m%,) produced both increases and decreases in K' relative to pure polycrystalline Al2O3. The results are examined in conjunction with the corroded surface phase assemblage detected through X-ray diffraction analysis. Under certain conditions, intergranular attack is impeded by formation of the reaction products CaO-6Al2O3 and 2CaO·Al2O3·SiO2"--Abstract, page ii.

Advisor(s)

Anderson, H. U. (Harlan U.)

Committee Member(s)


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

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering

Publisher

University of Missouri--Rolla

Publication Date

Spring 1985

Pagination

x, 121 pages

Note about bibliography

Includes bibliographical references (pages 103-106).

Rights

© 1985 Robin Ashley Murphy, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 5205

Print OCLC #

13141321

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