Effects of phase separation on crack growth in borosilicate glass

Abstract The effect of phase separation on crack propagation was determined in a soda-borosilicate glass. Crack velocity - K I curves in the velocity range of 10 −9 to 10 −4 m/s were shifted to lower K I with increasing heat-treatment time. A velocity plateau of 10 −4 m/s occurred, independent of heat treatment conditions. It is shown that the compositional changes in the SiO 2 rich phase formed during heat treatment controls crack growth rates. Results are discussed in terms of glass corrosion mechanisms.