Influence of Microshrinkage Cavities on the Plastic Deformation and Fracture Under Tensile Loading in Ferritic Ductile Iron

This work focuses on the study of the influence of microshrinkage cavities on the plastic deformation and fracture of ferritic ductile iron. Cast samples were especially developed to include dispersed microshrinkage. Tensile testing and digital image correlation analysis are employed to assess the influence of dispersed microshrinkage cavities as preferential sites for crack initiation and propagation under uniaxial static load. The results show that small microshrinkage cavities of up to 3.5 times the area of graphite nodules are not linked to the initiation and propagation of cracks in ductile iron. The methodology developed in this work becomes useful to evaluate the influence of size, distribution, and morphology of different microshrinkage defects on the damage evolution during tensile loading.