抄録
There is a potentially hazardous finishing process in which hydrofluoric acid is used to etch glass surface 10-100 μm depth to increase residual stress hence bending properties. However, the environmentally-friendly process of water treatment (WT) on the flexural strength (σ_b) and its bending strain (ε_b) of ultra-thin soda glass was studied. Water treatment mostly improved the σ_b and ε_b by the annihilation of residual stress at surface in the soda glass. On the other hand, the electron beam irradiation (EBI) mostly improved the σ_b and ε_b by the generaton of residual compressive stress probably occurring in front of crack tips in the soda glass. WT for short period gets the dull of the sharp tips of Griffith crack, whereas small dose of EBI cut the chemical bonds and generated dangling bonds at terminated atoms with both repulsive force and stress relaxation. Thus, enhancements of bending strength of glass treated by both WT and/or EBI can be explained. The enhancement of the final process of both WT and/or EBI can often improved the yielding ratio in industrial production process, the large cost reduction can be expected.
