Biaxial Flexure Strength and Dynamic Fatigue of Soda–Lime–Silica Float Glass

Abstract

The strength and dynamic fatigue behavior of float glass was investigated using biaxial flexure tests. The samples were tested using the ring‐on‐ring (ROR) biaxial flexure test geometry, and the data analyzed using a conventional two‐parameter Weibull distribution. The as‐received samples revealed that the air side exhibits a higher characteristic strength (243 MPa) compared with the tin side (114 MPa); fractographic analysis confirmed the presence of significantly larger flaws on the tin side of the specimens, presumably due to contact damage by the rollers in the float glass process. Dynamic fatigue results for as‐received and indented samples were performed to assess whether differences in the stress corrosion behavior of float glass exist because of tin penetration. No statistical difference in the stress corrosion exponent was found between the air (n= 21.7) and tin (n= 21.6) sides of the float glass. This indicates either that the tin penetration (which extends ∼25 μm) plays no role in altering the stress corrosion susceptibility of float glasses because the native flaw size is larger than the tin penetration depth or that the tests do not have the required sensitivity to distinguish the effect of the tin. Alternative test methods for direct observation of slow crack growth in tin‐doped bulk glasses are planned to investigate this in the future.