Palmqvist method
The Palmqvist method, or the Palmqvist toughness test, is a common method to determine the fracture toughness for cemented carbides. In this case, the material's fracture toughness is given by the critical stress intensity factor KIc. It was developed c. 1962.
Approach
The Palmqvist-method uses the lengths of the cracks from a number of Vickers indentions to determine the fracture toughness. The Palmqvist fracture toughness is given bywhere HV is the Vickers hardness in N/mm2, P is the indentation load in N and T is the total crack length after application of the indenter.