The Strength of Silicate Glasses: What Do We Know, What Do We Need to Know?

In the last few years, there has been increased interest in methods to improve the practical strength of inorganic glasses. During this same time period, new theoretical and experimental techniques have appeared. In this paper, we discuss this interest and indicate how and where these new techniques may help us to achieve our objective to increase the practical strength of glass. Our ability to measure the intrinsic inert strength of glass fibers as well as the development of stresses around indentations and scratches now allows us to attack these two important issues experimentally. Likewise, major advances have been made in techniques for the modeling glass structure and mechanical properties. The advances in these three areas give us indications of how changes in glass composition and processing can influence the final strength as well as its robustness.