Effects of EB irradiation on fracture toughness were studied for soda lime glass and glass fiber. The EB irradiation improved the hardness, ductility, fracture stress and fracture toughness. The fracture stress was 1.43 GPa for the glass fiber before EB treatment. The irradiation enhanced the fracture stress. The fracture stress at P_f=0.5 was 1.89 GPa for glass fiber samples treated by 65 Mrad-irradiation. It was approximately 0.46 GPa larger than that before EB treatment. Based on ESR results, the reinforcement can be explained. The changes in fracture stress were in good agreement with the density change in dangling bonds, because a high tensile glass fiber was obtained at 65 Mrad-irradiation. Thus, we confirmed that the glassy cluster structure with high dangling bond density was obtained in high tensile glass fibers prepared by 65 Mrad-irradiation. The EB irradiation controlled the fracture toughness of glasses. To confirm the mechanism, an alpha-aluminum oxide crystal sheet was also studied.

Date Published: 13 November 2002
PDF: 8 pages
Proc. SPIE 4934, Smart Materials II, (13 November 2002); doi: 10.1117/12.468652

Published in SPIE Proceedings Vol. 4934:
Smart Materials II
Alan R. Wilson, Editor(s)