Toward glasses with better indentation cracking resistance

The microcracking sequence (radial, median, lateral, and ring-like) arising at the glass surface under sharp contact loading and the extent to which these cracks develop is intimately related to the way the material attempts to relax the corresponding stress field. Two processes which are known to occur upon indentation are densification and isochoric shear flow. The contributions of both mechanisms were quantitatively assessed for glasses belonging to different chemical systems in previous papers [1], [2] and [3]. In the present study, indentation cracking maps are provided, which offer guidelines to the design of glasses with better surface damage resistance based on their elastic properties and hardness.