Conclusions
Due to their lightweight, magnesium alloys are very attractive materials for transportation industry. Therefore, un understanding of fracture behavior of these alloys is essential. Notches are unvoidable and their presence possess a risk against structural integrity of machines. The quasi-static fracture of ZK60-T5 magnesium extrusion has been investigated for U and V notched specimens. The followings summarize the major outcomes of this research:
  1. Mechanical tests show that the notch acuity is inversily related to the ductility
  2. Fractographic observations indicate that the material exhibits fibrous and shear failure mechanisms that are common in ductile materials.
  3. The FE-SEM fractographies confirm that increasing the notch acuity reduces the ductility as shown by the reduction of the shear lips size with the increase in the notch acuity
  4. Observed secondary cracks are attributed to the presence of high stress field near the notch tip and due to stress triaxiality.
  5. The strain energy density criterion was successfully used to estimate the fracture load of U and V notched specimens with different sizes and geometries.