Nanoindentation Method for Measuring Residual Stress in Brittle Materials

Abstract

The lowered threshold load for cracking with the cube‐corner indenter has been used in developing a method that can be used to measure residual stresses in small volume brittle materials. By studying a series of orthogonal cracks generated at loads not exceeding 10 mN with the cube‐corner indenter, a variation of crack length with position around a large Vickers impression in soda–lime glass was observed. Using an indentation fracture mechanics approach residual stresses were evaluated at the positions where the cube‐corner indents had been made. The stress values thus evaluated were generally higher than those reported in the literature where micro‐Vickers indents had been used to measure the stresses. Possible reasons for the disparity are discussed.