Masters Theses

Keywords and Phrases

fatigue; fracture toughness; Glass; stress corrosion; Subcritical crack growth

Abstract

"Delayed failure in silicate glasses can be linked to subcritical crack growth (SCCG) where surface defects grow over time until catastrophic failure. This phenomenon originates from stress-enhanced chemical interactions between the environment (e.g. water) and the strained silicate bonds at the crack tip. SCCG must be accounted for to predict the long-term survivability of silicate-glass components. This study compares two methods to measure SCCG parameters for a commercial alkali silicate sealing glass and for a series of binary xNa2O-(1-x)SiO2 glasses, where 0.15 ≤ x ≤ 0.35. A constant moment double cantilever beam (DCB) technique was used to directly measure the three regions of crack velocity (ν) as a function of stress intensity (KI) to describe the conditions of SCCG up to catastrophic failure. The two-point bend (TPB) method was used to determine failure strains as functions of relative humidity for fibers drawn from melts of the same glasses. The fatigue parameters calculated from the dependence of failure strain on the TPB faceplate velocity were then compared with those obtained from the direct velocity measurements by using a power-law model to calculate the Region I crack velocity" -- Abstract, p. iii

Advisor(s)

Brow, Richard K.

Committee Member(s)

Miller, F. Scott, 1956-
Watts, Jeremy Lee, 1980-
Strong, Kevin T, Jr.

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Materials Science and Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2024

Pagination

x, 49 pages

Note about bibliography

Includes_bibliographical_references_(pages 45-47)

Rights

©2024 Noah Weyrauch , All Rights Reserved

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 12433

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