Doctoral Dissertations


"Triaxial porcelain bodies containing various forms of silica, quartz, cristobalite and fused silica, were strength tested in bending. Significance tests were employed to discern real differences in the strength sample statistics caused by the various forms of silica. Firings were performed at three temperature levels. The differences in strength sample statistics were correlated to the microstructures of these silica porcelains.

A triaxial alumina porcelain body was employed as a model brittle solid for a study of the effect of flaw density on mean fracture stress. The flaws were introduced in the form of large diameter (d̄ = 115 microns) rounded quartz grains which underwent severe microcracking during cooling from temperatures in the maturing range. The fracture stresses were determined using a diametral loading method. The mean fracture stresses for large samples when plotted versus quartz particle concentration demonstrated a log concentration dependency for Quartz particle concentrations below 2.5 weight percent. The equation relating mean fracture stress to flaw density (quartz particle concentration) is one predicted by statistical theories of the rupture of brittle solids.

Deductions on the nature of quartz-associated flaws In triaxial porcelains were made based on the results of these and other recent studies reported in the literature.

The theory and practice of the diametral loading technique were analyzed, especially the practice developed in this study for the tensile testing of porcelain bodies"--Abstract, pages 1-2.


Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering


Missouri School of Mines and Metallurgy

Publication Date



xii, 163 pages

Note about bibliography

Includes bibliographical references (pages 135-140).


© 1962 Robert Eugene Moore, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Ceramic Materials -- Testing
Strains and stresses -- Mathematical models
Ceramics -- Microstructure
Strength of materials

Thesis Number

T 1379

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