Indentation fracture toughness of amorphous steel

Indentation fracture toughness experiments were performed on amorphous steel. Measured toughness values were 3.2 ± 0.3 MPa for 3-mm-thick specimens and 3.8 ± 0.3 MPa for 10-mm-thick specimens. Crack geometry was determinedto be of the “Palmqvist” or radial configuration. High indentation loads >40 N were necessary for crack formation, and indentation cracks did not form adjacent to every indent, or in a uniform pattern. Possible reasons for crack formation thresholds and geometry are discussed.