LAUSR

Abstract The casting defects from a Fe-rich Al-Si-Cu alloy were characterized by micro tomography and Finite Element Analysis. The specimens were analyzed in a high resolution computed-tomography scan and the 3D geometry of the casting defects were segmented in a rendering software. Shrinkage pores of various shapes as well as large plate-like s-Al 5 FeSi inclusions were identified and their 3D volumetric model was imported into a FE software tool in order to calculate the stress concentration factors caused by these defects. In the case of the shrinkage pores, maximum K t factors ranging from 4.73 and 14.56 were obtained located at the holes and dendritic arms of the shrinkage pores. For the s-Al 5 FeSi particles, the highest stress concentration factors were located at the edge and the protuberances of the inclusions and ranged between 1.74 and 3.46. Large clusters of these s-phases were observed, in which micro-pores were retained. After heat treatment, a significant fragmentation and dissolution of the s-Al 5 FeSi inclusions was found together with an increase in the ductility and ultimate strength of the alloy.