Influence of biaxial pre-deformation on fracture properties using pre-notched small punch specimens

In recent years, the pre-notched or pre-cracked small punch test (P-SPT) has been successfully used to estimate the fracture properties of metallic materials in those cases where there is not enough material to identify these properties from standard tests, such as the CT or SENB specimens. The P-SPT basically consists of deforming a pre-notched miniature specimen, whose edges are firmly gripped by a die, using a high strength punch. The novelty of this paper lies in the estimation of the fracture properties using the P-SPT on a material previously subjected to a biaxial deformation by the Marciniak stretching test. The obtained results show a linear decreasing fracture toughness tendency under the influence of biaxial pre-strain in plane stress conditions.