Comparison of the fracture toughness of high temperature ceramic measured by digital image correlation and indentation method

Abstract EN

The application of indentation techniques to the evaluation of fracture toughness is examined critically using Vickers indentation.

The fracture toughness values calculated by this method are independent of the crack profile and of the applied load.

This formula has been used by Anstis et al to median-radial cracks over a wide range of loads in the case of brittle materials (Alumina).

Also, the fracture toughness was measured using digital image correlation method for observing the crack length and the crack tip.

The load was applied using four point bending rig.

The Fracture toughness will show whether there is any significant residual stress in the surface which will affect smaller cracks.

The fracture toughness values were more accurate using digital image correlation due to the crack length and the crack tip was very clear and it is colored.